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greentoe357

why are all these leaves growing so small?

greentoe357
10 years ago

In the latest months I've noticed new leaves on several of my plants grow out very small and stop growing. It's not necessarily that the whole plant has stopped growing - just the new leaves come out stunted.

I do have artificial lights above most of these plants and water and fertilize regularly, even now in winter (half-strength Foliage Pro 9-3-6). The only thing I can attribute this to is maybe spider mites. I was able to see them before, gave showers and alcohol spray treatments to those affected plants. Now I cannot see spider mites no matter how hard I look. The plants where I see smaller than expected leaves are maranta, calathea, ficus burgundy and phalaenopsis orchids - all potentially succeptible to mites and in fact maranta and ficus definitely had them.

Can mites stunt the growth of leaves like this? And why do I not see them when they were visible before?

Comments (60)

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago
    last modified: 9 years ago

    GT - Before you abandon what you're doing and go off on a wild goose chase, keep in mind that there are thousands of people growing in bark-based soils that have never been happier. Leaching of nutrients isn't an issue limited to soils with bark in them, it goes hand in hand with any soil with a high organic content because of their low bulk density and their chemical make-up. Leaching is as large a problem in peat-based soils as it is in soils based on pine bark. The only time it's a problem is when you don't fertilize frequently enough or during prolonged periods of rain.

    The color of a plant has nothing to do with its need for phosphorous. most plants use phosphorous in a N:P ratio of about 10:1.5, or 1.5 parts of P for every 10 parts of N, or 6-7X as much N as P. Your 9-3-6 is entirely appropriate for at least 95% of the plants you might grow, including maranta and ficus. Blooming plants use P at the same average ratio as plants that have inconspicuous blooms or don't readily bloom indoors.

    Plants don't tolerate lower light levels better because they slow down. The symptoms of low light just aren't as noticeable as they would be if the plants biological clock was telling it to grow like crazy, and other cultural conditions (like temp) were more conducive to growth.

    Michigan State University has developed 2 orchid fertilizer formulas that are very widely used for orchids, one for tapwater and one for RO filtered water. If you do a little research, you'll discover their formulation very closely mimics that of FP 9-3-6. They don't suggest varying application of their formula with a formulation that has a higher P content at certain times of the year or when the plant is in a particular growth phase; and it stands to reason, because no one changes the nutrient supply in nature as the plant moves through its annual cycle.

    BTW - small leaves aren't a symptom of low light. Large leaves are, along with long internodes. Smaller leaves occur in response to very bright light, tight roots, low fertility, or dense ramification in the top of the plant. Do your plants need repotting? How often are you fertilizing/ how much? Are you flushing the soil when you water?

    To me, the maranta looks like it's asking for more light and being over-watered. What say you?

    Al

    This post was edited by tapla on Sun, Jan 26, 14 at 12:11

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    > do you think your growing conditions are the same now as in summer?

    No, so I can't blame the seasons exclusively. I changed most of my plants' mix types this past summer (including mixes of the three pictured ones) and added artificial lights, and many of them responded with better growth - some soon after repotting, some much later, like this winter. So it may not be that they are growing because it's winter - it may be because they like the mix, they are just showing it with a delay and growing despite it being winter.

    > did you have better larger growth on all 3 plants before?

    Only on the maranta. That thing was growing last winter on a shady window, pre-lights, in a peaty mix, like clockwork, and the leaves were larger and darker-green, more normal looking. It even flowered on that window sill, although not in winter, I don't think. Only problem was it was one long vine that never branched. I cut it up and rooted the cuttings (on that same window sill, no lights, bagged for humidity), and what you see here are those rooted cuttings.

    The other two never had better growth for me. The ficus was suffocating in a horrible soil, so I repotted it. There were a couple of pushes of new leaves all over the plant since then, each next one pushing the leaves smaller than the last.

    The Phals are rescues from Lowes outdoor racks where rain was pounding on the packed sphagnum peat on the pots. There were barely any live roots on one and none at all on the other Phal. But now that they live in a better mix and are growing roots, I'd expect the leaf growth to be better.

    > i know you repotted your cals in 511 and probably all else?

    Calatheas yes, and they love the finer more water-retentive 511 mix. but most others (the ficus and maranta) are in gritty mix. I may try the 511 mix for the maranta as well, as it's a relative of Calathea's.

    The Phals are in a mix of 3 parts pine bark (>3/8ths of an inch, what was too large for gritty mix), 1 part coarse perlite and 1 part long sphagnum moss.

    Re fertilizer, I do use Foliage Pro at half strength at almost every watering, except for shower days every month or two (my plants love it!) and when I am lazy and just water with plain off-gassed water, but I was wondering what would happen if I fertilize with a stronger solution, maybe starting in the spring. I know Al, you do this and are happy.

    I am unlikely to use different ferts for different plants or at different stages of their development. It just sounds too complicated for me. Mixing two solutions, walking around with two bottles (three actually, because I also need plain water for some plants.) Ain't nobody got time for that! :-)

    > Are you flushing the soil when you water?

    Yes. Water once, wait a few minutes, water again till it drains freely.

    > Do your plants need repotting?

    Definitely not the ficus and not the Phals. Maybe maranta - that one has had roots waving hello to me from the drain holes for a while now. But it was repotted last just in June, so it's unlikely that it's too tight inside the pot.

    > To me, the maranta looks like it's asking for more light and being over-watered.

    You mean it's asking for being watered more, or that it's being watered too much?

    It's in gritty mix, and I water every 3-5 days. It's raised above its saucer, and when I water, I do not always get rid of the effluent, except when it reaches the bottom of the pot. The roots peeking out under the pot may be submerged though at times. (Bad idea, I know, but can it cause the small/light leaves?)

    Than you, all.

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago
    last modified: 9 years ago

    Here is the goal that you should have in mind when you fertilize anything in a container (second time I posted it today): You should work toward ensuring that all the nutrients plants normally secure from the soil are in the soil solution at all times, in the ratio at which the plant actually uses the nutrients, and at a concentration high enough to ensure no deficiencies yet low enough to ensure the plant isn't impeded in its ability to take up water and the nutrients dissolved in water. This goal is easily achievable using one water soluble synthetic fertilizer. You CAN use organic forms of nutrition, like fish/seaweed emulsions or various types of meal, but that makes it much more difficult to achieve the goal.

    The maranta has the look of a plant that's over-watered and over-fertilized. I grow under lights & fertilize at every watering, using 1/4 tsp of 9-3-6 per gallon of RO filtered water. Flush the maranta thoroughly & start over with a low dose for the winter. Repot in summer & I bet it turns around. If it's going to need annual repotting, you might as well use the 5:1:1 for that, too.

    The next time you water, take note of how many days it is before the maranta starts to wilt. It will recover quickly if you're checking it a couple times each day and act as soon as you notice the wilt. Then make your watering interval a day or 2 less than that water-to-wilt interval. You might be over-watering.

    Al

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    > The maranta has the look of a plant that's over-watered and over-fertilized.

    Out of curiosity, can you break down what you see that tells you (a) over-watering and (b) over-fertilizing? I would love to be able to read the signs like this, but... scusi... no habla lingua planta...

    > I grow under lights & fertilize at every watering, using 1/4 tsp of 9-3-6 per gallon of RO filtered water.

    Same here, except the water is off-gassed and filtered, not RO. And I just water with plain water a couple times a month and try to give them a shower once a month or two - this is the leaching part.

    > Flush the maranta thoroughly & start over with a low dose for the winter.

    It just so happens that today was shower / no fertilizer day! Is 1/4 tsp/gal "low dose", or should I lower it?

    > The next time you water, take note of how many days it is before the maranta starts to wilt.

    It does its praying thing, so leaves often point down. What would be the sign of wilting for it then?

    > You might be over-watering.

    In gritty mix?!? Well, I guess it's still possible because I've gotten lazy and have not been tilting pots lately to let more water escape - even such chunky mix as gritty mix does have some perched water. And I also do not always keep the drain saucer empty. The pot is raised a bit, but the lowest roots, esp. the ones out of the drain holes, might be sitting in effluent occasionally.

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    smirk-smirk...how about just putting your maranta back in peat?
    it did like it,no ? or is it against the religion :))?
    besides, if it's cuttings - it's a very young plant. juvie leaves come out small and on variegated plants will not have the full markings - so it might be ok.
    however, ....all publications/growers that i find on sites recommend rich soil containing organic matter - sphag peat would be the closest subs.
    you might just need to increase it in your mix at least.

    considering your phal was without roots - new growth coming small is normal- it's like a baby plant. even with healthy plants when they start regrowth first leaves come out smaller, then they increase. in general..the growth on orchids is seasonal, mostly in summer (rainy season).

    so that leaves ficus: is it still limp? tent it to increase humidity/temps. it should perk up the leaves.
    if your temps are low (on the floor? near window?) - it will slow down the water intake. did you check the roots yet?
    if you suspect mites - spray with neem, dry, then bag. it'll help to isolate it too.

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Green, I didn't read all the replies, so I apologize to anyone who might have answered your question.

    Can mites stunt leaf growth?

    Yes. Not only do mites stunt growth, leaf color pales, looks dusty and leaf shapes may alter.

    If you're 100% certain mites aren't the problem, a second reason leaves aren't normal size is low/er light.

    Heck, I've purchased plants grown in FL and HI..Leaves were double the size..after a few months in IL, 'especially in winter,' new leaves are half the size..half if lucky.

    The same plant grown in-ground resume large foliage, but only those who live in high-zone states are lucky enough keep in-ground year round.

    If you have access to a garden during summer, plant an extra cutting, tropical or succulent, in-ground. You'll be amazed how large leaves get.

    Did anyone suggest the paper test to check for mites?

    Your Maranta, 'Prayer Plant,' doesn't look bad. Yes, some leaves are smaller, others have a little brown, but this is to be expected.
    Maranta's need high humidity, semi-cool temps and fresh, circulating air. I think Maranta is more difficult than their cousins, Calatheas.

    Plants like people need sleep. Dormancy. The reason I do not fertilize during winter months..or until new growth resumes.
    Someone tries stuffing food down my throat when I'm asleep, they're in for a bop on the head. lol.

    Toni

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    found an interesting point about light for maranta summer vs winter:
    Because the vibrant colors of the foliage can fade in bright light, the Maranta should be kept in partial shade especially during the hotter months of the year. During the cooler winter months, the Maranta should be moved to a brighter area that provides a fair amount of sunlight but still should not be left in direct sunlight. Direct sunlight will not only dull the vibrant colors of the plant, it can scorch the leaves .
    a couple of places mentioned that it needs MORE light in winter.
    it would help if you had a light meter or app to find out.

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Al, I swear...I have 15-plus bottles of fertilizer in a back room cabinet. Miracle to Peter's to Jack's Classic to Dina-Gro ..the lables all say plant food. :)

    I think most gardeners know and agree how fertilizer works. I think...???

    Al, If IL wasn't cloudy several weeks to months, 'okay, maybe a day or two of sun,' fertilizing, 'at least imo,' wouldn't be a problem, but winter is dark.
    I feel it risky fertilizing, applying nutrients, and/or unnecessary.

    When I say winter, I don't mean official dates. For instance, although it's cold, 'no not cold, freezing,' the days have been very sunny. Snow helps, reflecting light, blah blah.
    Some plants, such as Geraniums and African Violets get .25 dose, starting in Jan-Feb. If days are sunny.
    Both are in southern windows and receive 8-hours of artificial light. If only humidity was higher, but that's another issue.

    Hi Petrushka. You're absolutely right about Calatheas, and family.

    Cals dislike heat and direct sun.

    Our local conservatory has Calatheas growing in-ground, where temps are cooler than chilly. I once placed my hand on the soil, it was cold to the touch.

    They're planted near a huge, man-made pond. Taller plants blocked sunlight. Beautiful species.

    Toni

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    toni,
    i have a totally dif experience with maranthas/cals in conservatories: both in NYC bot garden and in fairchild gardens in miami, FL they are planted in tropical 'hot' rain forest part of conservatory - and they florish there year round.
    a lot of sites show 65F-80F range with 65F being the winter min, not the preferred temps. preferred temps for growth are 70s. i would not call it cool :), but it's all relative of course. that is why stating actual temps is far more accurate then using 'hot/warm/cool' descriptions.
    greenT's temps of 68-72F are OK for 'cooler' season for all 3 plants. in summer i would raise it to 72F-75F if possible.

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    I put Maranta closer to the lights, and that browned the leaves (see photo). So back onto the lower shelf it goes.

    During the cooler winter months, the Maranta should be moved to a brighter area that provides a fair amount of sunlight but still should not be left in direct sunlight. Direct sunlight will not only dull the vibrant colors of the plant, it can scorch the leaves .

    Maybe I should move it to an even darker place - the leaf color and size were good on a darker window sill with no artificial lights at all.

    it would help if you had a light meter or app to find out.

    I already installed a few apps - just have not gotten around to measuring. I have no way of calibrating though, so these will be comparative measures, not absolute. Still helpful, I hope.

    smirk-smirk...how about just putting your maranta back in peat?

    Haha I will likely do that. Well, not into straight peat, of course, but a mix with bark, perlite and some peat. My calatheas like that mix, and maranta is a cousin of theirs, so I have hopes for that.

    considering your phal was without roots - new growth coming small is normal- it's like a baby plant. even with healthy plants when they start regrowth first leaves come out smaller, then they increase.

    Good point.

    so that leaves ficus: is it still limp? tent it to increase humidity/temps. it should perk up the leaves.

    Yes, still limp. I bagged it - good idea as always. And yes, it's relatively cold, about a foot from a window, about 65 degrees or so.

    Maybe I should bag the maranta too - it's not a fan of dry air.

    Did anyone suggest the paper test to check for mites?

    Not yet, but I was able to see them before with my naked eyes, and now I can't.

    I feel it risky fertilizing, applying nutrients, and/or unnecessary.

    I use half dose, it runs right through the mix, I do flush and it's never entirely "winter" under lights. The maranta is growing - it's just growing progressively smaller and paler leaves. So I feel like fertilizing is ok.

    Thanks, all, appreciate the answers.

    Here's my sad little plant. Perhaps repotting is now an emergency? I have high hopes for bagging as well.

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    i have a totally dif experience with maranthas/cals

    Of the 4 Calatheas I've grown, I find them very different from one to another. Roseopicta was the first, in the times before I got a bit of a clue - that one just saw its leaves desiccated from outside in when the air was dry. Makoyana also tends to do that in dry central heated air - although now I am doing a somewhat better job of keeping it bagged for humidity but out of the bag for ventilation (a fine line at times). I find "Tropical Satisfaction" and Ornata more cooperative. They do not need to be bagged, I find, and both are growing new leaves this winter, although some leaves have also dried on the Ornata.

    I kind of like how they "talk" to me. I get excited when I am able to correctly read what a plant is telling me, and that has happened multiple times with Calatheas - and the maranta until this most recent fit now that I am having a problem reading into.

  • plantomaniac08
    10 years ago
    last modified: 9 years ago

    Greentoe,
    Oh no! I'm sorry to see your plant burned! I know "grow lamps" can be a bit warm for plants if placed too close. :\

    I'm not sure repotting would be a good thing right now as it may "shock" the plant even more and make it worse off than it already is.

    Planto

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    OMG! this photo is just 2 weeks later? this looks really bad - i'd say a goner...:(... but many people post that they look really ratty by march and THEN regrow!
    brown on edges of leaves of spath/cals indicates low humidity - they really HATE it.
    i would stop watering and bag it and put it on the window where it liked to be. if and when the leaves perk up and the top half of the pot is dry - then give it some minimal drip of water. do not drench to run thru. do not mist. do not allow condensation on the bag.
    as a desperate measure (i'd be desperate, believe me) i'd pull it out, clean it up and put it in barely moistened perlite and bag it too - on the window. basically treat it like a cutting to be rooted.
    funny (sad) that you said it was better on the window in peaty mix - that's your 'writing on the wall' there. give it what it likes!
    also books say: they need high humidity even in lower temps (60s). so bagging should help any way you look at it.

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Green...poor Maranta, although yours looks a he$$-of-lot better than mine.,.In fact, it might go in the compost.

    Plants in the Marantaceae family differ. Ctenanthe and Stromanthe are hardier than Maranta, thrive in lower humidity. Thrive in lower humidity without brown spots.

    Green, you mentioned Roseopicta. I find they're less difficult than Maranta, but much fussier than Stromanthe and Ctenanthes.

    I don't have a problem fertilizing during winter, if there's sun and a plant/s producing new foliage. Plants talk, we listen.

    I've seen photos of fertilizer burn..Brown spots on foliage. Just a thought. Toni

  • plantomaniac08
    10 years ago
    last modified: 9 years ago

    Greentoe,
    I hope your Maranta makes a comeback. Perhaps just placing where you had it before and repotting it down the road (once you start noticing that it's recovering) will bring it back to its former glory. I kind of feel bad now telling you that it was suffering from lack of light, only for you to move it closer to your lights and it burned.

    Toni,
    I don't want to jinx myself, but I've had an easy time with my Maranta for some reason. I have it on a humidity tray and it's about ten feet from a South window. I also keep it consistently moist (it's not in Al's mix though). I've only had it for about three weeks now, but its already produced four new leaves and the "overall" size of the plant has doubled. It's starting to create that "vine" look to it. *scratches head*

    Now, if it dies on me down the road (I hope it doesn't though, I've already grown to like it a lot and even Hubby finds it fascinating), that will be a different story and I'll slap myself for "jinxing" it.

    Now, the only Calathea I've ever owned, however, I call that "the fastest dying plant I've ever owned." I think I should have left it where I found it. I'd been eyeballing it for weeks and decided to finally pick it up. I found it was inside a cache pot, completely soaking wet. I took it out of the pot, dried it out best I could (it didn't dry out completely), and placed it back on the pot. Overnight, the leaves all curled up and the plant flattened on the pot. It never recovered.

    Some people can grow the most "difficult" plants and have a hard time growing "easy" plants. It just depends on the person I guess. Not saying I can grow anything difficult, all I have that I'd consider "difficult" would be my Maranta.

    Planto

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    it's very difficult to judge light levels around the room. it's even more difficult to compare it to art.lights levels. that's where the meter is a must.
    you have your app, even if you can't calibrate, you can still take readings by the window and at dif distance from your lights - you will be able to gauge the relative difference. i am very curious, since i don't do lights at all.
    planto,
    i think the maranta was under the lights even before greenT posted here. it's not clear, if he actually moved it even closer since jan24 ?
    greenT,
    can you clarify, if the decline on last pic that happened in last 2 weeks was immediately after you moved maranta closer to the lights? from where to where?

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Morning,

    Planto, cross your fingers, toss salt over your shoulder, don't break any mirrors or walk under ladders. :)

    I know what you mean about jinxing yourself. Last week I was telling a friend no mealybug this year. Yesterday, I posted on the String of Heats thread about mealy.
    Today I check and found mealy on my Schefflera. Talk about jinxing.

    If you can grow Marana without problems, God Bless You. That's a compliment, btw.
    I used to kill Pothos, one of the easiest plants ever!

    Yep, I agree growing the fussiest plants come easier to some and the easiest plants die..

    This year has been he$$...Seriously.

    Hopefully, now that daylight is longer plants are starting to send out growth.

    Do you summer Calatheas outside? They love fresh air, but need shade as discussed in this thread.
    The shadiest area outdoors is brighter than the sunniest indoor window.
    Thankfully, the gangway has enough shade to keep Calatheas, and bright enough for Hoyas to bloom.

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    Planto and anyone else, please do not feel bad whatever happens! And do not be discouraged to comment in the future. Marantas are widely available here for under $4, so I can restart it at any time.

    Green, you mentioned Roseopicta. I find they're less difficult than Maranta

    It's been the other way around in my experience - but things like this should not be a surprise because people's environments differ. Growing a maranta has been good for me and I'll grow one for sure going forward. Still hoping this one is not a goner, but time will tell. I bagged it and moved it well away from lights, more than 2 ft.

    Some people can grow the most "difficult" plants and have a hard time growing "easy" plants. It just depends on the person I guess.

    Yeah, my satin pothos (Scindapsus pictus), a very easy one for many people, is not doing well at all for me this whole winter. But that's another story.

    I've seen photos of fertilizer burn..Brown spots on foliage. Just a thought.

    Toni, I do not think that's it - it just happened really quickly under harsher lights.

    can you clarify, if the decline on last pic that happened in last 2 weeks was immediately after you moved maranta closer to the lights? from where to where?

    Yeah, Petrushka, I moved it from about 9 inches under lights to top of foliage to just a couple inches under lights. These are relatively cold lights (T5HO), but still.

  • plantomaniac08
    10 years ago
    last modified: 9 years ago

    Toni,
    Hehe, thanks for the compliment. I just read about your Scheff having mealy bug. :/ I hope you get all the critters. It's one thing to throw away a plant that you have little to no attachment to, but in your case, I'd fight for it too.

    Green,
    Thanks. :)

    Planto

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    GT, first, what does app stand for?

    I'm not following the comments about your Maranta...are you saying it burned because of gro-lights?
    If so, what type of lights do you have? Fluorescent or incandescent?

    I have different shelves with lights. 7 different types. None get hot enough to burn foliage.
    One lamp holds a standard incandescent bulb..It can get warm, but not hot enough to burn leaves. If foliage is touching the bulb, it browns.

    Planto. You're welcome.

    Yeah, I'm so disgusted. I detest mealybug.
    They're gross to look at, and the harm they do to plants!

    You're right..plants we love, sentimental value are harder to ditch.
    3-years ago I tossed 30-something African Violets because of mealy. One was a trailer sowed from seed.

    The same year I discarded all but one Clivia. Let me tell you, ridding was difficult.

    Last summer, it was Hoyas. Some of my favorites went in the trash..plastic bag, directly in the garbage bins, hottest week of the year.
    A few Clivias were shipped from China..variegated. Got them on sale, now they're 35.00 and up. sigh.

    The title, why are leaves growing small.
    New foliage should grow larger now that days are longer. I notice a few Philodendrons new growth are bigger..
    The last time Philos were fertilized was last autumn...foliar spray with Fish Emulsion..before that, each got a dose in August 2013.

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    GT, first, what does app stand for?

    Application/software - in my case to be installed on my smart phone in order to measure light intensity through its camera sensor. Sorry, I myself hate when people use abbreviations that may not be familiar to others.

    I'm not following the comments about your Maranta...are you saying it burned because of gro-lights?

    A very good question actually. Yes, I was saying that, but it may just be a coincidence. There was some browning of leaf margins (probably because humidity is low) even before I moved it, but then the browning accelerated - for the lights reason or maybe because of something else.

    what type of lights do you have? Fluorescent or incandescent?

    T5 High Output fluorescents. 2 fixtures: the top one has 4 bulbs and the bottom one 2 bulbs. (See the photo at the bottom.)

    I have not seen leaves browned like this before this maranta, unless they happened to directly touch the bulb (happened with other plants). Online sources do say that foliage is unlikely to burn even an inch away, as long as no part of the plant is touching the bulb. I do not know, maybe it wasn't the lights that browned the maranta leaves.

    New foliage should grow larger now that days are longer

    My plants' days last 16 hours to the minute on timer all year long. Earth's axial tilt be damned! :-)

    So, I finally measured light intensity on and around my plant stand.

    I had no way of calibrating the meter, so the results only make sense comparatively and not on an absolute basis.

    At ~10 am on a sunny day (but my window is west-facing and is well shaded by surrounding buildings in any case):

    (all numbers are in lux and measured at foliage levels)

    Top shelf (under the 4-bulb fixture): 2500 to 4500, ~4000 where the maranta was before burning.

    Second top shelf: 25 to 120 where the light is obstructed, 440 where there are fewest obstructions above.

    The shelf above the rooting containers (under the 2-bulb fixture): 2400-2600 directly underneath the fixture where the maranta leaves browned the most; 250 for that purple Tradescantia zebrina to 1400 for the Phalaenopsis, both in front and a little away from the light fixture, so light levels are lower there.

    Rooting containers: 630 in the back / 280 in the front of the larger container; 360 / 290 in the smaller container. For a measure of reference, this is not enough for some hoyas to get the most attractive foliage, as their leaves became darker there and lost red colors and bright leaf venation. I am gradually moving some of them out for this reason.

    Finally, on the window sill ~ 8 ft away from the plant stand: 25 to 80.

    What I see here is (1) just how drastically different the numbers are between the shadiest and the brightest spots, even on the same shelf, but also between neighboring shelves, and (2) the maranta light levels were actually lower (not higher) in the two weeks when the leaves burned more. Even though it was closer to and directly under the lights, but the lights were 2 bulbs, vs. prior to that where it was further, but from the 4-bulb fixture. So, I guess it's not the lights then.

    Hope this is not too confusing the way I wrote it.

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    GT, before I forget, again, what's the plant next to your orchid in photo 4? Love its leaves.

    Green, thanks for app definition...I don't have a Smart Phone, or heck, know what one looks like or what it does. :)
    Sorry you had to answer a question I know nothing about. Too technical for my simple brain.

    In one of my older plant books there's a section on cameras and foot candles. The author explains how it works, but the camera is older model.

    Instead of worrying about foot candles, I bought a few light meters, years ago, although I haven't used light/soil/pH gauges in a long time. BTW, all were accurate.

    Many African Violet enthusiasts set plants 2-3" from bulbs. No leaf burn.
    Perhaps there's another reason your Maranta spotted. I honestly think it's low humidity.

    God, what a beautiful light shelf! Wish I had one. lol.
    Years ago, I bought a stand..problem is it's wide instead of tall.
    The shelf is adequate for seedlings and shallow plants, but would never work with tall greens.

    Believe me the shelf was expensive. A few weeks after it was delivered, we went to Hauserman's Orchid Nursery.
    There stood a plant shelf, similar to yours for 100.00 more. I wanted to cry.
    Rooms in our house are small..so tall opposed to wide makes sense. Wanna trade? lol.

    Your plants look fantastic, very healthy.

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    i was surprised too at how quickly the light levels drop if you draw a sheer on a sunny day ;).
    very approx 10lux =1fc for conversion convenience.
    as i posted above from what i found (mostly from production guides - for fastest growth) maranta/cals is at 1000-2500fc
    my stromanthe triostar gets probably 800-1000fc at best with some 1-2 hours of dappled sun under the shelf 1' from the window about 3' high from the floor, that's for active growth in 75F and/or on heating mat.
    but for more then half of the year (and now too) it's at 500-650fc and it's doing OK. it's not growing new leaves, but it's not declining either. i am of a mind to put it on a heating pad soon - need to go buy another one.
    so yours was at 400fc and 250fc for the last 2 weeks?
    h-m-m...the burn does not sound plausible.
    also your west window measurement is impossibly low. it makes a dif how you point the camera. ideally you put a white paper where the plant is and point at that directly at 90 degrees angle. but so long as you maintain the same angle you should at least get relative numbers.
    when you place the camera under lights do you position it up towards lights or from the side? you should position it at the window in the same manner. directly into the light source (direction of strongest light). try it again.

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    GT, before I forget, again, what's the plant next to your orchid in photo 4? Love its leaves.

    Top right is a Hoya brevialata. She threw a hissy fit of the century when I dared to repot it from Exotic Angel soil. But what parts of it survived recovered nicely and is actually about to bloom! I see them at big boxes occasionally, or I can trade or share cuttings if you want when it warms up.

    Top left is Hoya wayetii and bottom right is a mini Cyclamen - in case you meant one of those.

    In one of my older plant books there's a section on cameras and foot candles.

    Yeah, Petrushka wrote about it above. I do not have a camera though other than the one in my phone.

    There stood a plant shelf, similar to yours for 100.00 more. I wanted to cry.

    I hate it too when that happens!

    A $100 MORE though? This whole stand was $80 when I bought it, and now I see it is even cheaper at $75: http://www.homedepot.com/p/Honey-Can-Do-5-Shelf-14-in-D-x-36-in-W-x-72-in-H-Chrome-Shelving-Unit-SHF-01443/202493258.

    I wanted something as tall as possible - just like you said, for effective use of vertical space, but also for better micro-climate plants create when there are more of them in a group. They come in two depths, I think, and I wanted this narrower one like the one in the link- again for space reasons but mostly because this is for display, and the plants in the back are going to be obstructed anyway on a deep shelf. Finally, the width - I'd prefer wider for my space, but this is the widest they came in at an economical price (or at any price - I do not remember now).

    It works very well with the 4-foot light fixtures. The light is a foot or so longer, which I was concerned about initially, but happy about now. You can shift the light off center to the side in order to light up a very tall plant that would not fit on the shelf - exactly like I am doing with that tall pot on the floor.

    I am very happy with the setup. One improvement I see making is to suspend the top light from hooks in the ceiling. Voila - one more lit shelf available for plants! I'll probably need another 4-bulb fixture then, to place exactly where the top light is now. But arguably, I need more light in there anyway, especially if the goal is to pop the color and venation on my favorite hoyas' leaves and to make them bloom more often.

    so yours was at 400fc and 250fc for the last 2 weeks?
    h-m-m...the burn does not sound plausible.

    Yeah. I am glad I did the light measurements. It was probably low humidity that was drying the leaves.

    also your west window measurement is impossibly low.
    you should position it at the window in the same manner. directly into the light source (direction of strongest light).

    Yes! I realize now that you mentioned it that I did it wrong. Under the lights I faced the phone straight up. By the window, I laid the phone on a window sill, so again pointing up, but that of course is not the direction of the strongest light. And another thing - the window frame's lowest parts were obstructing the light. "At foliage level" would be higher than where I measured, and so no obstruction by the frame parts. Duh. I'll redo out of curiosity.

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    Oh, and another "shelf" can be obtained on that unit if you set the lowest plants on the floor and raise the lowest shelf above them. I am doing that on my picture, but it may not be obvious. That empty shelf right above the rooting containers is the freed-up one after I put the containers directly on the floor.

    I need to re-jiggle the shelves now and may have too many actually for the heights of my plants, but no big deal - I'll just remove one in that case.

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Morning,

    GT, wrong photo. :)
    The plant that looks like Saxifragia/Strawberry Begonia. Fuzzy leaves. Jan 21st post. Sorry, should have typed the date.

    Ohhh, thanks for the link. I'll have to check it out.
    I have a home-made shelf with lights, but it was built 1994/5, seen its last days.

    75.00! You're joshing, right?
    Does the shelf include fixtures? Sheesh, glad I didn't buy the other unit.

    Here's my 'collecting dust,' shelf. See how wide it is?

    {{gwi:71337}}

    Btw, how much space between tiers? In other words, what's the tallest size plant that'll fit between tiers?

    Tier space on my home-made and a second shelf is 18". Not enough room for mid-size plants.

    One last question..is the shelf near a window, too?
    Thanks, Toni

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    var sources state differing ranges for light req . here's one
    •Low: min 25 fc to 75 fc, 75fc to 200 fc for good growth
    •Med: min 75 fc to 150 fc, 200 fc to 500 fc preferred
    •High: min 150 fc to 1,000 fc, 500 fc to 1,000 fc preferred
    •Very high: min 1,000 fc, 1,000+ fc preferred
    by the way one place said to point camera from high angle 1 foot from the plant when taking measurement. i assume high angle is like 20-30 degree from vertical?
    measurements can quite differ depending how you point.
    i myself just take it as guidance, not exact answer.

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    yet another stated this:
    Most plants will survive illuminance 10 times lower than listed below but will not grow as well or bloom.
    Low (500 - 2,500 lux; 50 - 250 fc) - North window at 40 latitude, 3 - 10 ft from fluo-lights
    Med (2,500 - 10,000 lux; 250 - 1,000 fc)
    - East/West window at 40 latitude, filtered daylight, 1 - 3 ft from fluo-lights, 5 - 10 ft from a 400W metal halide light bulb
    High (10,000 - 20,000 lux; 1,000 - 2,000 fc)
    - Full Daylight (10,000 - 25,000 lux), South window at 40 latitude, 2 - 5 ft from a 400W metal halide light bulb
    Very High (20,000 - 50,000 lux; 2,000 - 5,000 fc)
    - Direct Sun (32,000 - 130,000 lux), 1 - 2 ft from a 400W metal halide light bulb

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    >> another "shelf" can be obtained on that unit if you set the lowest plants on the floor

    Sigh. I did that, and did not think of the fact that the tile floor is very cold. The heating mat underneath is half-way under each of the two containers. So, three cuttings among those that were not sitting directly on top of the heater started rotting. I cut off the bad parts, washed the better parts in soapy water, disinfected the cups, applied cinnamon to roots and re-potted into fresh medium. And of course I put the containers back onto a shelf and put a blanket in there that was there before.

    Toni, do you mean the plant in the attached picture? It's a mini cyclamen from Trader Joes, but they sell them everywhere. I do not grow begonias.

    >> 75.00! You're joshing, right?
    Well, plus tax. :-)

    >> Does the shelf include fixtures?
    Nah, that would be TOO good. They are around $100 to $130 or so each, bulbs and delivery included.

    >> Btw, how much space between tiers? In other words, what's the tallest size plant that'll fit between tiers?

    That's another good thing about this unit and similar ones - all shelves are adjustable up/down in an inch intervals. If you need even taller shelves, you can just remove one or more shelves. Or add shelves (sold separately) for more shelves of shorter heights.

    >> is the shelf near a window, too?

    About 8-9 feet away, on the opposite wall of my dining area.

    Petrushka, where do you get these recommended light levels for different plants? When I google a plant name plus the word "care", I never get those - I get more of a lame person's culture information. Perhaps I should google things like "cultivation guidelines" or something?

    I re-measured light on my window sills (no obstructions, pointing at the max light, on a largely cloudy day but with lots of reflected light from snow outside the window). The results are 102 to 232 fc. That's more like it.

  • pirate_girl
    10 years ago
    last modified: 9 years ago

    Gosh Eugene (GT), that is one STUNNING looking Cyclamen photo -- Bravo!!

    Karen

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    Well, that photo is straight from the store. I was too lazy to take a new picture. It's much shaggier looking now, although the number of blooms exploded (30+ in a 4 inch pot, many drying up, but new buds rising up all the time).

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    GT, that's it...a Cyclamen!!

    Very pretty.

    Aw, your shelf is adjustable..Lucky. My metal shelf is not.
    If I can find a similar shelf, perhaps I'll remove fixtures from an old shelf and attach to a metal shelf.
    Finding adjustable shelves might present a problem though. At a reasonable price...

    Karen, just noticed you named the plant..thanks..Toni

  • greentoe357
    Original Author
    10 years ago
    last modified: 9 years ago

    >> Finding adjustable shelves might present a problem though. At a reasonable price...

    See my link from a few days ago above. Or is it not exactly what you are looking for?

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    my 2nd post at 17:56 is from wiki of all places :)
    http://en.wikipedia.org/wiki/Houseplant_care
    search for : plant light requirements lux
    often artificial light companies put up elaborate write-ups.
    i do not do lights, but when i stumble upon one - i take notes.
    http://www.sunmastergrowlamps.com/SunmLightandPlants.html info on PAR which was new to me.
    this is on a well known site:
    http://tinyurl.com/ms2yrp3
    http://www.zone10.com/plant-lighting.html was good.
    var .edu and especially fl. university production/growing guides are excellent: though those are for optimal green house conditions usually. but since most house plants are grown there i find it very useful as perhaps unattainable but detailed guide.
    then there are special flowering plant societies like
    orchids, broms, aroids to look at.
    it takes time for sure. and google is not what it used to be.
    most of the time it is very difficult to find specific lux/fc numbers for one plant. even "foot candles" in quote pulls a lot of garbage. same for "lux".
    often generic guides are wrong about 'specialty plants'.
    the other day i stumbled upon 'common house plants grown in avg conditions will need to be replaced after 2 years' - so that's the expectation!
    i have found that generic light guidelines for the public are not enough for good growth, unless you aim for high margin.
    it's tough. but para-phasing mulder "hard data is out there". and i have a knack for finding it :).

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Pet..I just noticed your comment about sheer curtains.
    Yes, sheers definitely block light rays.
    I no longer hang curtains or blinds...long ago, I had an old camera that displayed fc. What a difference!

    Pet, where did you find, "the other day i stumbled upon 'common house plants grown in avg conditions will need to be replaced after 2 years' - so that's the expectation!"

    Do you agree???

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    somewhere .. i don't save links like that. or 90% of sites that i go thru, only those with the best info.
    but it seems that's an avg houseplant life expectation. and if you look at majority of posts in 'house plants' - you'll prolly agree that it's true ;).

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago
    last modified: 9 years ago

    Plants are organisms that can only react to their situation - to the conditions under which they are grown. If the life expectancy of a plant in situ (where it naturally occurs) is many, many years, while the life expectancy of the average houseplant is only 2 years, the responsibility for the difference falls squarely on the shoulders of the grower. It's possible that a grower might be unaware of methods that allow the grower to maintain plants in good health for many decades or beyond, or the grower might prefer to keep replacing plants as they die because of the extra effort it takes to maintain them in good health. What's important to understand is the 2 year cycle of decline followed by the death or discarding of the plant is what it is, but it doesn't have to be.

    Al

    This post was edited by tapla on Sun, Feb 16, 14 at 15:39

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Pet...2-years isn't very long for common plants.

    Pests can wipe-out an entire population..Over and under-watering, diseases.

    With proper care, basic plants should live 20+ years.

    Perhaps, people starting out lose plants...

    Gift plants are hard to keep. Azalea, Cyclamen..I can't keep Poinsettia so don't bother anymore..Others grow Poins like weeds. Weeds that flower.

    I don't know..

  • petrushka (7b)
    10 years ago
    last modified: 9 years ago

    i think you misunderstood me.
    i thought it was quite outrageous to declare the avg life-span of a house plant to be just 2yrs.
    unfortunately a lot of people don't even bother to find out what their plant needs, yet to actually GIVE them what they need?!
    yah, sometimes they get carried away - and get a plant they def DONT have conditions for. then it would be much sooner then 2yrs - more like 6mo!
    also, what i was saying earlier.. i think that generic guidelines for what kind of light the plant needs - are way too low and vague. what's low what's bright where, when? often the low margin - is what the plant will barely tolerate without dying. and people somehow construe that they can grow at these levels.
    it would me much better to get fc or lux as a ref point. but that is difficult info to get.
    my plants refuse to die.. joke - actually even my 'mity' overwintered ivies persist for 4-5 years.
    and my base core of plants i've had for 20yrs. and they can certainly go longer. and most likely will.
    so perhaps 'life span' is not a correct term - but what would be the correct term? 'how long on avg the plant will survive at home?' too wordy.
    anyways, i was sort of ranting...

  • birdsnblooms
    10 years ago
    last modified: 9 years ago

    Al, I must have been typing minutes before you submitted..I didn't mean to cut you off.

    Pet...I guess we're all guilty of buying plants that have requirements we can't possibly offer.

    One reason I'm grateful greens can be summered outdoors.

    Succulents need high light..in an apartment/house they do not get the sun they need.
    Tropical plants need high humidity and fresh, circulating air which is difficult to duplicate.

    After years of growing, I think indoor gardeners have an eye for light levels.

    Because our place has windows facing every direction, 'although not perfect,' light is fairly decent.
    For humidity, I use humidifiers, an indoor fountain, misting, showering, treys, and place little cups of water behind plants..still humidity isn't suitable for high-humidity plants.

    I don't know the life span of a plant indoors..It depends on care and plant type.

    I compare the lifestyle of birds. A parakeet or cockatiel, in the wild, has a life span of 30-years.,.'if they don't get shot by farmers.'
    Larger parrots live longer, some 80-90 years.
    As a pet, the life span decreases..quite a bit. 7-10 years average.
    My Mystic lived 17.5 years..he was a Godsend. My female cockatiels lived 7-9 years. Mystic's son, Sparkle is about 8-years,.He's very healthy...but when you least expect it....
    Plants, like birds need nutrition=vitamins, light and proper foods.
    Thankfully, birds do not need soil, so there's no debate there. :)

    Some plants are short lived...I have a plant book that lists short-lived gift plants..I do not agree on all mentioned.
    Cineraia, tuplips, florist mums, etc.

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago
    last modified: 9 years ago

    Oh - I didn't feel cut off at all. One of the main reasons I spend time at GW is because I recognize that the 2-year revolving door policy on plant replacement needn't be. I've been sort of following the thread, but not closely. It just seemed like a good spot to emphasize that any grower that wants to can break free of that whole short life span way of thinking if they want to.

    I'm sure there are a lot of growers that just accept the short life span idea as the natural progression of things. Hopefully, just the statement that it needn't be so will be enough to give pause to people just passing through the thread - sort of pique their curiosity and make them want to learn more about maintaining plants over the long term.

    Al

  • greentoe357
    Original Author
    9 years ago
    last modified: 9 years ago

    Here's an update on what happened after February 8th, since the time of that pic with lots of dried up leaves.

    This is taken about a week after, on Feb 16th:
    {{gwi:71338}}

    Yes, that's a penny next to those leaves. They were coming out even tinier than before. Repotting it or figuring the culprit further was not high on my priority list, so I stuck it in a random place (bathroom under fluorescents) and basically forgot about it, except for watering/fertilizing with other plants, of course.

    This is a pic from today:
    {{gwi:71339}}

    The two biggest leaves here are the newest just unfurled ones. They are not huge, but they are ~3 times longer than those penny-sized ones, and they are much healthier looking.

    It looks like the small leaf problem is reversing on its own - well, maybe it likes the place I put it into, but it happened without repotting.

    So, can somebody venture a guess what this was about? Is winter to blame, and now spring is credited for the recovery? (The plant is indoor and under lights though.) Humidity is probably not it - it is in the bathroom, but only one shower daily is taken there, and the door never closes, so humidity drops very fast. I don't know what else it could be.

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    .... seems to be looking better.

    A good % of plants really start to develop a full head of steam when day length becomes longer than night length (at the vernal equinox around or on 3/21). If the plant and soil can be lifted from the pot intact in mid-June, repotting it should be very helpful in restoring the plant's ability to grow like it was genetically programmed to. Notice I didn't say "give it a boost", or predict "a growth spurt"? Repotting it will simply eliminate or reduce the limiting effect of root congestion, which allows the plant to grow closer to how it would normally grow (w/o the limitations).

    Best luck!

    Al

  • pirate_girl
    9 years ago
    last modified: 9 years ago

    Hi GT,

    Have you tried taking these plants out from under the lights?

    While I don't grow these, I did some quick reading on both these & their cousin Calathea & I read they do not like direct light, but rather need bright, indirect.

    I've read that can cause the yellowing.

    I read that these are South American tropicals, which I interpret as forest plants & some ground cover. In that setting, they'd never get direct light & likely would burn readily. They'd be getting very filtered, dappled light (NOT like Hoyas which are said to grow up the canopy into brighter & stronger light).

    Just a thought I think is worth trying (if it were mine).

  • petrushka (7b)
    9 years ago
    last modified: 9 years ago

    greenT,
    can you take a light measument? just so we know what kinda light you have in the bathroom :)? where the plant is. finally the leaves look normal. that's a relief!

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    Large leaves are symptomatic of low light conditions, so a reduction in the size of newest foliage is predictable as photo-period and/or photo-intensity wax.

    Al

  • greentoe357
    Original Author
    9 years ago
    last modified: 9 years ago

    > I read they do not like direct light, but rather need bright, indirect.

    My understanding was that even the strongest fluorescent T5 light you can give plants equals to this "bright indirect" light level from plant culture descriptions - because real sun is SO MUCH brighter.

    I was at an orchid show a couple of weeks ago at New York Botanical Garden, and they had a lot of companion plants including many species of Maranta and Calathea growing on the floor of the greenhouses. I should totally have measured the light there with my phone (unlike orchids, these did not seem to be temporary exhibit, so it would have been meaningful), but I did not think to do it. Maranta growing in the ground is quite a sight to see, by the way. It's a very low ground cover - its habit is to try to grow roots into the soil at every node, so it does not reach up at all, except for its tiny little purple (or white) flowers. Very cute. I am thinking how to replicate this look at home. When it was growing on my window sill a winter ago, a long vine crept along the window sill - and it did flower at that time as well. I cut it up at that time to fill out the pot, but I am starting to think just letting it crawl where it wanted to go was a better idea. It does not seem to want to grow upright at all.

    > can you take a light measument?

    I did, finally. On my light stand, it was getting around 200-700 fc (it was on the less bright shelf not directly under lights). On the bathroom counter, I get 15-20 fc. This is with an uncalibrated phone light meter app, so absolute levels may be wrong, but comparatively, they do tell a story, I think.

    The plant stand was getting 16 hours a day on a timer at the time, and the bathroom day is roughly as long (manual turn on/off), maybe a bit shorter.

  • petrushka (7b)
    9 years ago
    last modified: 9 years ago

    15fc is too low - remeasure. i think 150fc is the very lowest anything will grow in.
    although i found in one article that 3m from north window will give you a reading of 15fc. haven't checked that.
    but then again, so long as it IS growing,
    just leave it there.
    'bathroom day' - do you have a window there? or you keep the light on for 16 hours?
    this article below lists the lowest levels i've seen anywhere for low-med-high light levels.
    and it lists maranta at low-med of 75fc-200fc.
    good article in general.

    Here is a link that might be useful: light levels indoors at the end

  • greentoe357
    Original Author
    9 years ago
    last modified: 9 years ago

    Well, it was growing pretty far under 4 fluorescent bulbs, and there was another plant hanging above it obstructing the light a bit.

    I had an idea to mount a plant and hang it on the vent in the shower to the side of the light fixture, but light intensity there was 3 fc. :-( I should explore twisting one of the four bulbs to point that way, I wonder how much that will help.

    No window in the bathroom, but I do leave lights on for about 16 hours daily.

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