Return to the House Plants Forum | Post a Follow-Up

 o
The Myth of Winter Dormancy

Posted by karen715 z5 IL (My Page) on
Wed, Feb 11, 09 at 21:30

So much of the advice we tend to see this time of year, usually starting in fall and continuing until around now, revolves around the idea that houseplants go dormant during the darker days of the year. I used to buy into the idea myself, until I really started paying attention to my plants. I live roughly 50 miles northwest of Chicago in an area that experiences rather gray winters. (Some people will say that the sun never shines during the winter here. While that is obviously not true, we do seem to have fewer really bright, sunny winter days than I remember experiencing in the NY metro area, where I spent most of my life.) I have found that while it is true that many of my plants slow down in growth between say, early November to mid February, very few of them actually stop producing new growth during that time, which is what the word "dormancy" suggests. And some of them are actually quite active in the winter. As an example, here is a list of plants that have produced particularly noticeable, healthy new growth, or have flowered, between the winter solstice (Dec. 21) and now. I am only listing plants I grow in natural light, since one expects the growth of plants under lights to be fairly consistent.

Zamioculcas zamiifolia: 5 new stalks plus a new flower.
Monstera deliciosa: 4 new leaves in January alone.
Philodendron bipinnatifidum (aka P. selloum): at least 3 new leaves (slower than spring/summer, but still active.)
Aspidistra elatior: 1 new leaf (notable because these can be very slow growing.)
Paphiopedilum orchid: New flower (probably started in early Dec.)
6 different Hedera helix cultivars: All have continued to produce new leaves.
Chlorophytum comosum: New stolon produced.
5 different Epipremnums (pothos): All have continued to produce new leaves.
Hoya carnosa: Long vine on which several new pairs of new leaves are starting, as well as a new branch off of one the vines.
Trandescantia pallida: Intermittant flowering.
Peperomia incana: new leaves.
Dracaeana reflexa ‘Song of India’: new leaves, possibly a new branch (just noticed it, not sure when it started.)
Haworthia arachnoidea: 2 of them are flowering.
Echeveria NoId: also flowering.

The moral of this story? Well, other than the fact that Karen obviously needs to get a blog or a life, or both ;-), it is that one should always observe what one’s plants are actually doing, and attend to their needs accordingly, (including frequency of watering and fertilizing) rather than accepting conventional “wisdom” (don’t feed in winter) that may be well off the mark.


Follow-Up Postings:

 o
What the??!!

I don't know where those odd characters came from. They are supposed to be apostrophes. They certainly did not show up in preview.

To clarify, I'll repeat the final portion of the last sentence (slightly modified to avoid apostrophes, in case it happens again): One should always observe what your plants are actually doing, and attend to their needs accordingly (including frequency of water and fertilizing) rather than accepting conventional wisdom (do not feed in winter) that may well be off the mark.


 o
RE: The Myth of Winter Dormancy

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Feb 11, 09 at 23:16

I'm with you 100% on this issue. It's easy to build a very convincing case that those repeating the mantra "you shouldn't fertilize in winter or when a plant is not growing" are making some very broad assumptions and exhibiting a lack of understanding about water/soil/fertility relationships. It's easier to tell everyone to stay out of the water because a few can't swim, than it is to teach the few to swim.

For years I have grown houseplants under lights in a gritty soil that drains well & remains highly aerated. I use 6-8 drops of 9-3-6 soluble fertilizer in each gallon of water, EVERY time I water, all winter long (most plants). I eventually increase the dosage to about 1/4 strength during the more active phase of the growth cycle. Some plants get watered every day, most every other day, and a few every three days or more - all are watered so about 10% of the water I apply exits the drain - all are healthy & robust. If I wasn't growing under lights, I would treat them exactly the same, except that the lower light levels would probably extent the intervals between water/fertilization for an extra day or two.

Anyway - you make a valid point.

Al


 o
RE: The Myth of Winter Dormancy

I've found plants go in cycles, roots then leaves, and so on. It's true some plants do go dormant, meaning lose leaves and shut down. I've had citrus, ivy, and hibiscus go dormant inside, but I also feel this is when it's concentrating on root production.
I agree with Al on the not feeding during winter myth, you should feed something. I do not however feed for green growth in winter though. This is only because I grow cactus, epiphytes, which new growth would surely die in short order. Never mind that, I have blooms today :D My new Aporocactus and Rhipsalis are in bloom!


 o
RE: The Myth of Winter Dormancy

Thank You for this justification! I have been very lightly fertilizing certain plants almost all winter. These plants are described as "Everblooming", which means they have potential to grow and flower all year round. They flower every single time I give them fertilizer! (At this point, it's only once a month). The only plants that have gone dormant are two Plumerias. So- nothing for them.


 o
RE: The Myth of Winter Dormancy

Karen I would love to see your ZZ flower. I didn't know they did, but then again I never researched that they could either.
I have 2, 1 in a 8 inch pot and 1 new stalk this winter.
The other is huge in a 12 inch pot and 6 new stalks this winter. It's 3 feet tall and 4 feet wide. I think it might need repotting but it has to wait. it could use a little more light...sigh.


 o
RE: The Myth of Winter Dormancy

Gobluedjm, you aren't missing anything. ZZ flowers are as ugly as all get-out. They are typical spathe and spadix Aroid flowers, but the spathe is a plain pale green and the spadix is thick, brown and unattractive. But I'll take a picture once the current bud is fully open. :-)


 o
RE: The Myth of Winter Dormancy

Yes, I must agree, at least about ZZ plants.

I just posted a pic abt this at C&S. I just got a camera & posted a test shot of my ZZ unfurling a beautiful new shoot. Earlier I recall them sprouting new shoots in Sept., that's happened to me often, but never in Feb., I was so surprised!


 o
RE: The Myth of Winter Dormancy

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Feb 12, 09 at 15:44

Jeeli - We still need to be careful about limiting accumulations of soluble salts from fertilizers and irrigation water - all seasons, but especially as winter progresses.

The key is balance, and what facilitates balance is an appropriate soil. Plants absorb water best when there are NO nutrients dissolved in it - but that obviously creates a problem and the name is 'deficiencies'. On the other hand, as the level of dissolved solids in the soil solution increases, it becomes more and more difficult for water to move into cells. In extreme cases, when the level of dissolved solids in the soil solution is much to high, it can actually reverse the normal flow of water into cells so water is being REMOVED from cells.

Our job is to make sure that we have somewhere near the lowest level of all necessary nutrients in the soil solution that will satisfy the plants nutritional needs and prevent deficiencies. This low nutrient level in the soil solution insures an easy uptake of water AND adequate nutrition.

If our soil is so water retentive that we need to be concerned about root rot if we water copiously - it's a poor choice of soils. The reason is: a water retentive soil forces us to water in sips. This means that no water escapes the pot, and ALL the dissolved solids from both fertilizer AND irrigation water that are not used by the plant accumulate in the soil. We already know this makes it difficult for the plant to absorb water. I believe that this accumulation of salts in combination with low humidity is the primary reason most plants suffer so in winter.

Free draining soils allow you to water AND fertilize frequently at low doses, even in winter. As you apply water and fertilizer, the accumulating salts are dissolved and are carried out the drain hole. The old salts are replaced by a fresh supply in the water. Frequent watering also forces accumulating and potentially harmful gasses (like CO2 and ammonia) from the soil. It's a win/win, but you cannot simply continue to fertilize on a regular basis if you're not being careful to eliminate the old accumulating salts from the soil. Sooner or later, it WILL catch up to you. ;o) There are other ways of flushing the soil, but a fast & well-aerated soil, along with copious amounts of water when you irrigate is the best and easiest strategy.

What I said sort of makes you want to believe that those repeating the mantra 'fertilize weakly, weekly' know what they are talking about, but that mantra could easily be criticized for not adding a qualifier - 'fertilize weakly, weekly, but just make sure the sum of your weak weekly doses doesn't build gradually to the equal of a dose too strong.'

Al


 o
RE: The Myth of Winter Dormancy

Karen, you make good points about the meaning of "dormancy"...but may I point out....well, rather ask a question..."do you think the average houseplant person actually looks into whether their plant has added one new leaf since the last time they looked.

I think generally persons see their plants in an overall look...if it looks healthy and they water according to the plants needs, such one or two new leaves are not appreciably looked at as though it is growing.
Unless something unusual, like a yellow leaf, appears, most just go about daily care of their plants and water according to how the plant is using it.

I must caution readers to not believe everything that some might say about their watering habits on their plants.
To water a plant every day....or two....just goes far beyond reasonable thinking about what a plant can possibbly do with such watering routine.
The member uses a term "gritty"....and I have certain thoughts about what she means by it...."gritty" ..envisions all kinds of possible descriptions. To suggest what she implies is to say a plant should not store in any way, moisture it must have to survive; the water goes through it like the proverbial water on a duck's back. It doesn't stick around to make any impression.

If one reads other material, in other journals, in other periodicals, or pamphlets about routine care for our plants, one's eyebrows surely comes up with wide disbelief.
Do not ...I repeat, do not take this as any kind of expert suggestion from somebody who is knowledgeable about such practice. This is her way....she has stressed this soil question before and received questionable concessions to its viability.
Before you change your watering habits so drastically, I implore people to take it slow....read, and then read some more before believing your plants will benefit from such.
All manner of watering advice is exactly opposite to this member's views.

As far as believing a houseplant is in a growing stage when such winter sun says differently, can be taken with a grain of salt. There are indeed plants that do very well with low sun intensities.....we are often asked about plants that survive low light situations, and answer in the affirmative....there are many that can be given shady places....but we do repeat the caution...ALL PLANTS NEED SOME SORT OF LIGHT SOURCE....no plant can survive long in deep shade or darkness.
Some plants go against the grain of "best exposure"...and are prescribed to be placed into a northern exposure where they do well....in fact, very well.
But such numbers of plants that fit that description is few in number. Most plants, since they are of tropical nature, do best when given as much sun as we can give them without undue strain on their systems.
That is to say, they are given mostly good light....but not direct sun. To put a plant in this catagory into darkness is an excellent way to have it survive not very long.

Plants use sunlight, or other sources of light, and from this light use water and oxygen to maintain their system.
With such low intensity of sun, they slow down...and the question then is 'just how much do they grow with the limited absorption of such light and water'.
Whether one can view one leaf as a sign that the plant is actually growing, is ....questionable..in my opinion.
One might suggest the leaf came from what light it stored and is just now using it to advance small measure of growth.

We often are encouraged to put our houseplants out of doors when temperatures rebound. There, they grow in earnest and we are encouraged to feed them to support the added growth.
When such plant is not growing, (might be considered dormant) we are forever told to not water so much, not fertilize to encourage growth, but to care for the plannts only to bring them through such winter drab until the sun can improve their lifelong wish to grow, to prosper, to generate what they can, when they can.

From Karen's remarks, I suggest readers to carefully acknowledge that their plants are doing their best and not growing to the extent that increased watering or fertilizing is now what they should do.
Examine your plants, and treat any increase of watering according to how they are growing and using such increase.


 o
RE: The Myth of Winter Dormancy

Jeannie, it may be dorky but I watch with much excitement when I see a new leaf showing up!


 o
RE: The Myth of Winter Dormancy

Hi Daw,

I'm sure you're not the only one that does that. I think that's half the fun. Personally, that fun doesn't wear off even tho' I've grown for years now.

Just today I noticed the first tiny nubs of new growth on some new Thanksgiving cacti cuttings -- very tiny but still exciting. W/out tugging on it, those tiny nubs tell my repotted cuttings have now rooted -- yippeee!


 o
RE: The Myth of Winter Dormancy

Make that two dorks then.:-)


 o
RE: The Myth of Winter Dormancy

I don't mind being a dork from time to time. You'll have to work harder than that to offend me little man.


 o
RE: The Myth of Winter Dormancy

Don't know if anyone is still into the original subject of the post, but I can say that my Rhipsalis grandiflora is currently growing six healthy-looking new branches, to add to the four it grew after I bought it in October. I've got a feeling it reacted to being repotted and, being in a south-facing window, have had enough light to keep going despite the wintery sun.

I'm impressed with your ZZ, since mine have only just started growing a new branch again (it started in late fall but stopped growing for a few months). Might it be more/also a matter of warmth than light? My flat is pretty cold, down to 16C, and while I'm not good at fertilizing, the ZZ's been watered normally since fall.

(caveat: I took pretty poor care of it for a while and so its tubers were completely depleted last time I repotted. However, the new shoot appeared after this, so I don't think the dormancy was due to unhealthy tubers needing to "fill up".)


 o
RE: The Myth of Winter Dormancy

lol....'deja vu'! (Been back and forth on this forum since 1999)

I agree there are many plants that don't experience winter dormance, *if* their growing conditions are still ideal during the winter.

I have an Anthurium 'Red Giant' that continues to grow both new leaves and bloom stalks during the winter. This plant is just a short distance from a south window.

Many other plants that are 'banned', we'll say, to the interior portion of my somewhat 'dark' home with fluorescent lights nearby to maintain their health during the winter, do, indeed, experience a sort of dormancy.

Great topic, Karen.

Let's *CARRY ON*!


 o
Forgot

Forgot to mention...as far as noticing new growth on plants *now*...it is the middle of February, and as long as I've been growing plants indoors, it seems that the plants always *think* it's *spring* in February.

Hasn't anyone else noticed this in the past?


 o
RE: The Myth of Winter Dormancy

Yes, with the increasing light values and the warmth of the container media, houseplants do consider February to be spring (in many locales). If the light and temps are right, a plant doesn't really "know" spring from autumn, either.

Josh


 o
RE: The Myth of Winter Dormancy

I have a plant moisture regulator simply because I forget things. I check the moisture every day whether I have new AVs or years old, winter and summer. This really keeps me from underwatering which is my biggest problem. This is all very interesting reading.


 o
RE: The Myth of Winter Dormancy

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Feb 13, 09 at 15:51

Josh - plants actually do 'know' the difference between spring & fall & react quite differently. One generality: most plants will concentrate on extending the length of branches and growing new leaves, in the case of more herbaceous material, from the onset of spring growth until around the summer solstice. After that, they slow growth and concentrate on storing their energy (instead of using it like they did in spring) for the winter ahead.

Mortswife - be cautious about putting too much faith in your moisture meter. It actually measures the EC (electrical conductivity) of the soil solution instead of actual moisture content. To prove this, simply insert the tip of the meter into a cup of distilled water & note that it will read 'DRY'. Add a little salt, and the same water will read 'moist' or 'wet'.

Al


 o
RE: The Myth of Winter Dormancy

Yes, you're right. Artificial light and warm temps can't match real sunlight.

Josh


 o
RE: The Myth of Winter Dormancy

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Feb 13, 09 at 18:03

You might have missed the point, Josh. ;o) Plants' life cycles are controlled by rhythms (search endogenous and Circadian). Artificial light and warm temperatures alone, except under very specific and highly controlled circumstances, are not enough to trump these natural rhythms. If we think about it for a sec, the plant would have to repeat a 6 month growth cycle in order for spring and fall growth patterns/habits to be the same.

E.g. - I have a grow room in my basement that has only one, very small window at one end, the light from which is mostly blocked. My grow lights are on 16, off 8 every day, yet the plants unfailingly go through their seasonal cycles as surely as if they were growing in situ.

There's lots of additional physiological support for the fact that plants' responses differ between spring/fall. In spring, houseplants are often leaving a variable quiescent period and are ready to burst forth with robust new growth, while in fall, the plants are generally curtailing growth in favor of banking their energy for a winter's rest. ;o)

Al


 o
RE: The Myth of Winter Dormancy

Hi Nan, nice to see you posting! I first noticed that February was "Houseplant Spring" about ten years ago. Since I'm one of those folks who hates winter with a capital "H," the early indoor spring really cheers me up.

But most of the growth that inspired this particular thread actually occurred in January or before.


 o
RE: The Myth of Winter Dormancy

< chemistry major >For what it's worth, distilled water conducts electricity just fine, because it self-ionizes (as hydroxide and hydronium ions). Perfectly pure water contains both hydroxide and hydronium at a concentration of 1x10^-7 mol/L.

Electrical conductivity does increase as other ions are added, but that doesn't mean water won't conduct on its own. < /chemistry major >


 o
RE: The Myth of Winter Dormancy

I love inspecting the plants this time of year too - I definitely notice the plants starting to grow again, even though it's cold and nasty out and I hate winter and am depressed by it every year.

Of all the plants I handle, ZZ's seem to be the most consistent in sending up new shoots in the dead of winter, especially in December and January. I think they grow MORE then than they do the rest of the year. I have no idea why. And this is true for a bunch of them in different buildings.

I was on an orchid forum recently that told of an orchid company that treats "winter dormancy" as December and January only. After that, the plants respond to the increasing light after the winter soltice and thus get fertilized again.

I have always been very light on fertilizing my foliage plants, especially the larger ones, since I don't want them to outgrow their allotted spaces. And because I'm lazy. :) They get a dose of Osmocote in March and that's usually it. They do fine. Years ago, I had some that would go years with no fertilizer and they were fine too. I'm sure if I fed them more, they would be happier, but they are "good enough".

Now, with my blooming plants OTOH, the blooms slow way down or stop when I don't feed. So I can't afford to get lazy with them!


 o
RE: The Myth of Winter Dormancy

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Feb 14, 09 at 13:36

I do realize that distilled water does conduct electricity, but the conductivity of distilled water is actually pretty poor. I don't know how to show a negative power with the keyboard, so I'll just explain what the first line below means. It says that distilled water conducts 5.5 times (10 to the negative 6 power) Siemens per meter. This is 5.5 x -10,000,000 S/m or .00000055 S/m.

Typical conductivity of waters:
Distilled water ..... 5.5 x 10-6 S/m
Drinking water ..... 0.005 0.05 S/m
Sea water ............ 5 S/m

For the sake of discussion, let's pick a number for tapwater's conductivity (between 0.005 and 0.05), and set it at 0.01 S/m. .01 divided by .00000055 shows us that tapwater conducts 20,000 times better than distilled water, and seawater about 10,000,000 times better. The soil solution would be somewhere between the conductivity of tapwater and seawater, so if we take the mean, it would be around 4,990,000 times the better conductor. That's why the inexpensive meters read distilled water as being 'DRY'.

So we're not straying too far away from the topic: I noted upthread that it's important to limit the amount of salts in the soil because EC (electrical conductivity) has direct bearing on a plant's ability to absorb water. Especially in winter when we're tempted to water in little sips because the plants aren't 'drinking' much, the salts are apt to accumulate. Flushing the soil regularly (at least monthly), or better - using a soil that allows you to water freely enough that it flushes salts EVERY time you water, keeps the EC low and makes it easier for plants to absorb water.

Much of the leaf tip and margin burn we associated with winter's low humidity can be avoided by taking the steps to keep salt levels (and accompanying EC) low.

Looks like you're back on track, Karen. ;o)

Al


 o
RE: The Myth of Winter Dormancy

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Feb 14, 09 at 14:11

Lol - settle down, Josh. No need to come out with guns a'blazin'. ;o) I'm not sure, but I think this is the second time you took me to task for something entirely innocent. There was nothing harsh in my post - I'm sorry if you took it that way - and I sure didn't take anything you said as terse, nor did it rub me the wrong way - at all. I think that whatever's been going around might be catching. ;o)

You're prolly going to be more upset now, when I tell you we're STILL talking about apples and oranges. If you reread what I said, you'll see that I never mentioned 'artificial light/warm temps vs sunlight' before your reply that said "Yes, you're right. Artificial light and warm temps can't match real sunlight." because they don't matter.

After you agreed with something I didn't say, I felt compelled to make sure that you understood my only point was - plants DO recognize a big difference between spring & fall. It's their endogenous and Circadian rhythms that control this response - not light levels or light source. I was only compelled to add the fact that artificial light and warm temperatures, or artificial light and warm temperatures vs sunlight, really have no practical effect on a plant's o/a differing physiological responses to spring/fall AFTER you brought it up as a factor.

Karen - I THINK this is still on-topic, but if you consider this cross-talk - please let me know & I'll butt out.

Al


 o
RE: The Myth of Winter Dormancy

Lol - Ha! I'm quite settled, Al.
Sir, there be no guns here, blazing or otherwise!
And I appreciate the explanation.

To this, I was agreeing:
"Artificial light and warm temperatures alone [...] are not enough to trump these natural rhythms."
Respectfully,

Josh


 o
Winter Dormancy

I have a related (topical) question, if I may:

Last summer, I pruned my Christmas Cactus, and left it outside until late September. This was its first summer outside in all of its thirty years.

When I brought the plant back inside, it continued to grow new leaves but no flower buds. It wasn't until the very end of January that I saw the first buds begin to set.

During its many years of house-life, this CC has always bloomed right around Christmas.

I'm curious whether this Christmas Cactus will bloom in February again next year, or if it will bloom in time for Christmas.

Is the "late" bloom date due to the pruning, the summering outside, or a combination of both? Or something else entirely, perhaps?

Josh


 o
RE: The Myth of Winter Dormancy

It's shorter days and cooler nights that tell CC to start the blooming process. They need about 6-8 weeks rest in a cool dark place.
See the link below

Here is a link that might be useful: holiday cacti


 o
RE: The Myth of Winter Dormancy

I see that the window for blooming is rather wide, and my CC isn't off its timing after all. Thanks for the link.

I am curious, however - in the link, there was a red line stating that direct sunlight must never reach the Christmas Cactus (except in winter). I understand that these are jungle cacti, but surely some sunlight must reach them in the wild...more than an hour at dawn or dusk...

Josh


 o
RE: The Myth of Winter Dormancy

Mine gets a lot of sun in summer and I know friends that grow them also and they get sun also. Kind of difficult to avoid sun here in southern ca.


 o
RE: The Myth of Winter Dormancy

I question that caution abt no direct sun as well.

My last bloomer grew on the edge of a west window, half in the window half out. I didn't turn it (I hope to w/ the new one) & only the side in the window that got direct light bloomed. Also in summer, when the direct light was strongest, my new growth came in red-purple looking (from the strong light I've concluded).

As I mentioned elsewhere, these plants (CCs) are said to originate around the area of Rio de Janeiro, Brazil, where I was raised. Tho' I know they're said to grow in the tropical forests there & would naturally get dappled light through the canopy, I'm sure they also get SOME direct sun through that same canopy. I can't imagine how it could be otherwise.


 o
RE: The Myth of Winter Dormancy

Al, I don't consider any plant/science talk to be off-topic so by all means, carry on! :-)


 o
RE: The Myth of Winter Dormancy

an old thread, but an interesting topic!

Due to a pet issue, my living room is closed off at the moment, so all the plants were moved into the kitchen/dining area, where they wouldn't be forgotten about & are enjoying southern exposure during the Pacific NW fall/winter. It's pretty crowded, but also very enjoyable. Having everyone concentrated in the same room has made the fall foliage push very striking!
I'm telling myself that the additional O2 is good for my studying :)

At the moment - late November - pretty much EVERYONE is putting on some foliage, but most notably Monstera (7+ leaves on 2 plants), Jade (2 new leaves on the end of each branch), Clivia (4 new leaves), P scandens & B semperflorens (many new little leaves), Schefflera (still actively back-budding from a summer whack), Hylocereus (a new branch at base) and Avocado, D marginata & Pachira (all putting on new apical leaves & heading upward). The ficus friends are making new leaves, the spider plant is making babies... So much for "dormancy"!! Everyone (except for the parlor palm) is within 6' of a 13'x 6' window bank & receiving only natural light.

All this growing activity is making me actually think about a little fertilizer now & then, so that come summer I can do some pruning (top & bottom)... in fact, I was browsing about pruning when I crossed this post :)


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the House Plants Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here