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Fertilizing in winter

Posted by eileen_plants z6 NY (My Page) on
Mon, Dec 24, 07 at 19:43

Just finished reading the thread by shiver on fertilizing plants when in bloom and some of the related topics discussed prompted me to post this thread; please forgive me if I am repeating information from previous posts, or if the discussion deteriorates as shiver's thread did.

That being said, I am interested because two weeks ago, I considered whether or not my plants would need at least some nutrients to get them through to spring and decided to weakly fertilize. I used 1/8 the recommended dose of fish emulsion on all plants, and plan to do so again next month, or perhaps in 6 weeks. I know Al fertilizes each time, so I am hoping for the best, and would be interested to know what others think of my regime, either pro or con. It seems to me that a plant, even if dormant, would need some nutrients just to maintain its overall health, but I don't know enough about the technical aspects to determine this. I have a philo, three sheff's and a dieff, as well as several others that are putting out new leaves (before the recent fertilizing) - or am I completely off base and this no fertilizing in winter only applies to plants with flowers?

Hope I am being clear and not too much of a newbie, I've been keeping houseplants for about three years, so in comparision with those of you here who have been keeping plants for many years, I am still a novice. Thanks for any thoughts...


Follow-Up Postings:

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RE: Fertilizing in winter

Eileen, I think you are feeding your plants in an ideal fashion. Not so much to encourage growth when it cant sustain it, but enough to keep the health of the plant in mind.

I think the plants and hopefully you and yours will have a prosperous and happy New Year.

Merry Christmas.


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RE: Fertilizing in winter

There is absolutely no reason, if you have adequate light to sustain winter growth to feed 'foliage plants' continually. Not enough light can cause elongating of the stems, but these can be trimmed in spring and used for cuttings.

I use the word 'foliage plants' because they are usually grown for foliage, not flowers, this doesn't mean they won't flower if given the proper care though.


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RE: Fertilizing in winter

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Dec 25, 07 at 23:10

Hi, Eileen - The house is finally quiet after what seems like a recent whirlwind of activity over the Christmas Holiday, so I'll offer a few thoughts in the hope that what I say will ring true.

Houseplants go about the business of living and adjusting their metabolic needs according to certain internal rhythms and cultural conditions. Their internal clocks and lowered light levels are key factors in the marked slowdown most of us observe in our plants in winter; however, slowed growth cannot simply be offered up as proof of "dormancy". Just because we can't see plants growing or we think they are not growing is insufficient cause for certainty. In fact, in winter, our plants are carrying on photosynthesis and respiration - keeping their systems orderly, and going about their metabolic processes in a "business as usual" manner. They are just doing it at a much-reduced rate.

Why then, would we deprive plants of the building blocks they need (fertilizer) to produce the energy (make food) to carry on their metabolism? In nature, do the nutrients just disappear from soils whenever a plant's internal clock or cultural conditions cause slowed growth? Of course not - and the idea is absurd. Even if you cannot SEE plants growing, they are STILL producing and storing photosynthate to be used in a later push of growth. Withholding fertilizer, LIMITS the plants ability to carry on this important part of its growth cycle. Plants are efficient users of nutrients, but they cannot make something from nothing.

If you were striving for ultimate growth and best vitality, it would be REQUIRED that plants should ALWAYS have a full compliment of ALL the nutrients essential for growth in a solution strong enough to supply all nutrients in the adequacy range, but not so strong that it makes it osmotically difficult for the plant to absorb water and nutrients. This bold part is key.

The reason it is so often parroted that we should refrain from fertilizing in winter isn't because the practice itself is bad for plants (simple science and a little knowledge of plant physiology is all that's needed to dispel that myth); it's because so many of us are growing in a soil that simply will not allow us to fertilize in a way that is best for the plants.

Remember, I'm often at odds with growers who support a practice out of convenience or a necessity based on cultural limits they have either placed on themselves or that they must work within. Soo often you'll find me saying that grower convenience and plant vitality are often at odds with each other and are often mutually exclusive.

Where am I headed? Well, if we KNOW that availability of low levels of all nutrients at all times is best, even in winter, why are we so often admonished against winter fertilizing? It's because of the soils we use. Even without the addition of fertilizer to our irrigation water, the level of salts and total dissolved solids (TDS) in our soils (for most of us) continues to accumulate over winter because of watering habits necessitated by slow soils. Some limit themselves by soil choice and then try to tell others that ARE using a soil that allows them to fertilize appropriately that they are doing something wrong. This, because the some lack adequate understanding about what is really happening with regard to plant's actual nutritional needs.

So YES, many readers are limited to being unable to fertilize adequately because of soil choice, and just because plants carry through winter w/o additional fertilizer supplements over the dark months, is not an indication of anything except that plants will usually tolerate it. Is it the end of the world if you don't fertilize in winter - or you can't? Not really, but you can see that there really is a better way than simply withholding nutrients from an already stressed plant.

Dr. Alex Shigo: " ... correct the stress, which will lead to strain, that if uncorrected will lead to the death of the organism."

I use fast soils that drain freely & I fertilize with my own concoction (which is basically MG 12-4-8 with micronutrients + some STEM + some Sprint 138 Fe chelate [an iron supplement for high pH water applications] + MGSO4 + vinegar) at EVERY watering, and it works extremely well. When I add the TDS of my water and what I add to it, I'm applying the right mix of nutrients at every watering at a rate of less than 300 PPM of TDS which puts me on very sound horticultural ground. In summer, the same plants will be fertilized at somewhere near the rate of 1,500 - 2,000 PPM weekly - a big difference.

If I remember correctly, Eileen - you were asking about soil amendments in your area not long ago. I hope you found them and your question was prompted by your wish to experiment with a more open soil. If you are using a soil that allows you to water freely at every watering, you cannot go wrong by watering weakly weekly, and you can water at 1/8 the recommended dose at every watering if you wish (with chemical fertilizers, i.e. - there are some other considerations with regard to delivery of nutrients when using organic sources that depend on biotic activity to make nutrients available in elemental form, but I think they are outside the scope of the points I wanted to make in this reply).

Take good care.

Al



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RE: Fertilizing in winter

Well Al,
You said it way better than I could have. I did not mean to imply do not feed if you don't have enough light.


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RE: Fertilizing in winter

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 26, 07 at 6:57

Oh - I wasn't disagreeing with you, Mentha. We're really much closer to agreement on what was said than it appears at first reading, and I really have no quarrel with what you contributed. I was trying to reply pretty directly to Eileen's question & wouldn't have allowed what anyone else had already said to have much sway on what I had to offer. ;o)

Take care.

Al


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RE: Fertilizing in winter

Thank you very much for your post, Al, it was extremely helpful. Since reading your "A soil discussion" post, I am now using soil based on your recommendations. I have repotted 3 plants with the new soil, and they are all doing wonderfully, but I don't think I'll be repotting all my 85 plus collection just yet! I plan to do it slowly, possibly waiting until the spring; when they are all in fast draining soil, I will definitely fertilize more frequently. May I ask if you think my current regime (1/8 the recommended amount of fish emulsion every month during winter) is acceptable, keeping in mind my current soil mix is not fast draining? Any input greatly appreciated, and thank you for sharing your extensive knowledge with us all, I am certain others are equally grateful to you for sharing your expertise.


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RE: Fertilizing in winter

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 26, 07 at 17:49

Thanks for the thoughtful words, Eileen. ;o) I wouldn't expect anyone to simply up & change their soil mixes on my recommendation, but I'm always glad to learn that someone has kept open mind and is willing to try to personally validate the idea that long term aeration/structural stability is THE most important consideration in soil choice. I know you'll be very pleased with your adventure and deservedly so, as I think you went to some considerable effort. You have my admiration. ;o)

Here's the deal on fish emulsion: First, I just looked & I have gallon jugs of 0-10-10, 2-3-1, and 5-1-1, so I'm not sure what you might be using. Second, I'm not going to tell you that 1/8 strength monthly is going to be ok unless I know you're flushing the soil regularly - at least monthly. You have two factors at work that cannot be extracted from each other - the dissolved solids from fertilizer applications plus accumulating salts from your irrigation water. In the new, free-draining soil, you could fertilize weekly at 1/4-1/2 strength if you wish (though it's generally not necessary at this time of year) & no ill results will be made manifest.

I strongly prefer chemical fertilizers in the 3-1-2 ratio as they're readily available with micronutrients and are closest to the proportions of major nutrients that plants ACTUALLY use and what you'll find in tissue analysis (which is the basis of fertigation practices adhered to by commercial operations). That said, I suppose that if I had to choose only one of the fish emulsions, I'd have to opt for the 5-1-1 (but I'd probably add a little soluble potash to it, so I'd end up with something like 5-1-2, which is VERY good for a WIDE variety of plants.)

I'm guessing you're probably fine at 1/8 recommended dosages, but ..... Here's why I don't like fish emulsions in containers except under some specific circumstances: Delivery is unreliable and slow. You may not get the nutritional boost you need for a long time after you apply the fertilizer because it has to pass through the gut of microorganisms before it's broken down into usable elemental forms. Though not as much a problem in the 2/3 mineral soils you're experimenting with, in highly organic soils, it tends to carry over and accumulate. Since microorganism populations are normally boom/bust in containers, you can go from no nutrients being released to too much being released in a very short time. Elements can technically be abundant in the soil, but unavailable until complex hydrocarbon chains are cleaved, so even with plenty of N or other elements potentially available, nutritional deficiencies are entirely possible and they can swing to toxicity levels simply by way of increasing biotic activity in the soil.

Some of the things that affect the microorganism populations and availability of nutrients are moisture levels, pH, level of accumulated salts, and soil temperature. Any and all of these things cause wild fluctuations in microbial populations and availability of nutrients.

If you're set on growing organically, I won't try to talk you into a nice 12-4-8 or 24-8-16, both with yummy micronutrients, but if you're not - consider your arm twisted. ;o) It really will make life easier as it will be pretty near impossible to make sense of the results of your nutritional supplementation if you stay organic. I include blood/hoof/horn/bone/feather/meals and other organic forms of fertilizers as being much more difficult to manage effectively as well, though I respect anyone's want to use them.

That's about it from this perspective. I hope that doesn't confound rather than enlighten.

Al


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RE: Fertilizing in winter

Can't thank you enough for your help Al, and all the other great people on gardenweb who are so generous with their experience and knowledge. Yes, I am using 5-1-1 fish emulsion, but after carefully reading and (rereading!) your post, I think you have made a valid case for chemical feritilizers, which I will try come spring. I have only foliage plants; would the 3-1-2 ratio work equally well on plants that don't flower? Sorry for yet another question! Thanks again.


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RE: Fertilizing in winter

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Dec 30, 07 at 21:02

Yes, the 3-1-2 ratio will work fine for both plants grown for blooms or foliage. Tissue analysis of soft plant parts will show that roughly the same ratio of nutrients will be present in all tissues. This means that roughly the same ratio of NPK will be found in flower parts as you will find in leaves.

Here is a chart I put together that shows a range of the nutrients found in a huge % of various plant's tissues. I gave Nitrogen, because it's the largest nutrient component, the value of 100. Other nutrients are listed as a weight percentage of N.

N 100
P 13-19
K 45-80
S 6-9
Mg 5-15
Ca 5-15
Fe 0.7
Mn 0.4
B(oron) 0.2
Zn 0.06
Cu 0.03
Cl 0.03
M(olybden) 0.003

You can see that plants use about 6-7 times more N than P. The rest of the P in high-P formulations is wasted or acts as a stress agent. Simply reducing your N applications is more effective and better for plants than a high P blend. Reducing N slows vegetative growth, while allowing photosynthesis to continue w/o interruption. Since the plant is not making leaves or extending branches, it has plenty of reserve energy from its continuing photosynthesis and unused photosynthate to put into blooms and fruit.

Whats the harm in a little extra P? Well its more like 10-20 times the amount needed in some formulas. Even formulas like 20-20-20 and 14-14-14 have much more P than required for healthy growth. Excess P can immobilize some trace elements, as well as forming insoluble compounds with calcium. The result of phosphate overfertilizing is leaf chlorosis. Phosphorus is known to compete with iron and manganese uptake by roots, and deficiencies of these two metal micronutrients causes interveinal yellowing, so the chlorosis we might easily diagnose as a N deficiency COULD be exacerbated when we try to correct it by the addition of even a balanced blend like the commonly used 20-20-20.

From the chart above: If I average the range of P and K in plant tissues as compared to N, I come up with the values of 100-16-62. If I want to look at the values as a comparison to a 3-1-2 ratio, I simply divide each number by 33-1/3, which comes up to 3-.5-1.9, which is remarkably close to what is in plant tissues and the suggested 3-1-2 ratio blends. At first glance, it appears that the level of P might be low, but since P is usually found rather abundantly in highly organic soils like we use in containers, it's about as close to a perfect all-purpose blend as you'll find w/o engaging in measured fertigation.

As hobby growers, we need to take a shotgun approach & hope for the best, but I've talked with many people much smarter than I about what I'm sharing here, and I've had nothing but agreement. I really believe that in almost every case where we are growing in containers, that 12-4-8 or 24-8-16 liquid blends with micronutrients will give consistently superior results to either hi-bloom formulas or other commonnly used, balanced blends like 20-20-20 or 14-14-14.

Al


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RE: Fertilizing in winter

Thank you, Al. I wish you would seriously consider writing a book, you not only have a way of making the complex understandable, but pick topics that are very interesting, such as the soil amendment thread. You probably don't have the time, but you should give it some thought. It doesn't have to be a 600 page tome.

The hunt is on for a 12-4-8 liquid blend fertilizer!


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RE: Fertilizing in winter

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Dec 31, 07 at 9:10

It's very easy to find - you'll probably be able to get it at many nurseries & big box stores. There's a link to 4 appropriate 3-2-1 blends you can look at in the soil conversation thread. I'm reluctant to post links because I inadvertently set off a spam filter a few weeks ago & got a note from the powers, but just look for 4 hi-lited links embedded in the text of one of my replies about half-way down the thread. ;o)

Here is a link that might be useful: C'mon - I'll take you to the thread he's talking about. Just click me!


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RE: Fertilizing in winter

Hi again Al! Still doing research and just came across this thread. I'm better understanding fertilizers and ratios and the ingredients. I've thought of a new question that I haven't seen asked yet (probably because everyone else knows what they're doing, LOL).

So if I'm looking for a fertilizer with a 3-1-2 ratio... what would make me decide between, say, the 12-4-8, or a 24-8-16? They're the same ratio, but is the higher one stronger? Would I use a lower strength of it? I don't quite understand why they make the different amounts, like a 10-10-10 or a 20-20-20.

All my research seems to lead me straight back to you!! =)


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RE: Fertilizing in winter

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Jan 4, 14 at 13:50

If you called Dave from Dyna-Gro and ask him why he sells 9-3-6 AND 7-7-7, you'll get an answer like I received: ""Al - You are correct. We market high P fertilizers because people "believe" [his emphasis] they need them. As you have noted, our Foliage-Pro does a great job start to finish. However, it is simpler to give the market what they think they need than to try to reeducate it [my emphasis]. There is some evidence to believe that low N helps to convince a plant to stop its vegetative growth and move into its reproductive phase (flowering), but environmental factors are probably more important. P is typically 5th or 6th in order of importance of the six macronutrients. There is little scientific justification for higher P formulas, but marketing does come into play for the vast majority of users who lack any real understanding of plant nutritional requirements [my emphasis]. Therefore, the market is flooded with a plethora of snake oil products that provide little benefit and can actually do harm. For example, one exhibitor at a hydroponic trade show had a calcium supplement with 2% calcium derived from calcium chloride. Can you guess what continued application of 2% chloride would do to plants?'

I hope this answers your question and am sorry for XXX's (name deleted - his employee) inaccurate response.

Cordially,
Dave Neal, CEO
Dyna-Gro Nutrition Solutions ...."

Between MG 24-8-16 and 12-4-8, there is little or perhaps NO difference when applied at recommended rates, other than one is a liquid and one a granular, soluble product. MG has done the calculations for you, but it would roughly come out to the fact that you would use twice as much of the 12-4-8 product as the 24-8-16 product to reach solutions of equal concentration.

This relatively minor consideration holds true when comparing the two MG products, but when you change to a comparison of say 24-8-16 to Foliage-Pro 9-3-6, there are significant differences that affect growth, vitality, and appearance. 9-3-6 is a 3:1:2 ratio, but it also has ALL the essential nutrients plants normally take from the soil, in a still favorable ratio. This is significant because most soluble fertilizers, the MG formulations being discussed included, lack the macronutrients Ca and Mg. So if you're using a bagged soil and Miracle-Gro 24-8-16 or 12-4-8, you depend on soil breakdown and the lime added to the soil when it was made as a Ca/Mg source. The problem with that is, the Mg fraction of dolomite is about 125X greater than the Ca fraction - so guess what becomes deficient first. ;-) Using 9-3-6 regularly ensures the Ca:Mg ratio is always balanced and that both are always available. It's extremely important that nutrients less mobile (in the plant) nutrients like Ca are ALWAYS in the nutrient stream. If they aren't, cells can't form normally.

FP 9-3-6 also delivers most of it's N in nitrate form, and none of it in the form of urea, which is where MG's N comes from. Urea promotes large, coarse foliage and long internodes, especially under low light conditions often found indoors. Nitrate forms of N, on the other hand, encourage compact, bushy growth and shorter internodes.

I use 9-3-6 on everything. I modify it regularly, only for 2 plants - tomato and hibiscus; and the modification is as simple as including some extra K in the form of Pro-TeKt 0-0-3, which is also made by Dyna-Gro.

Fertilizing can be monkey easy if you are using a soil you can water correctly. It won't take long for you to see that in order to be a proficient grower, you need to take a holistic view. It won't do you any good to get the light right if you get the nutrition wrong; and the reciprocal is just as true. Good growing is about eliminating what is limiting your plant. In most cases, the limitations can be traced directly to a poor soil, so it always makes the most sense to look there first if you want to correct problems or improve proficiency.

Al


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