Flowering trees and nitrogen

[Leo in N E Illinois]

The traditional wisdom suggests that flowering trees will yield optimal blooms when fertilized with a low nitrogen fertilizer towards the end of the summer, through fall. The explanation provided is that higher nitrogen will result in more vegetative growth and less flower budding. I would have chalked this up as an old wive's tale, but I've heard it repeated by more than a few respected bonsai growers. On the other side, I'm hearing more and more people say that next year's buds are being grown now and high nitrogen will help these very buds develop. Not quite sure what to think.

Right now I'm using Peters 20-20-20 and would prefer not to buy a seperate "bloom promoter" fertilizer for my one Chaenomeles but if that's what would be best I'll do it. FWIW the Chaenomeles is developed, I'm just looking for maximum fruits, flowers, and ramification--in that order

This is BULLSHIT and it is BAD for YOU - a quote from George Carlin, which I always find amusing.

First let's clear some things up. What is a balanced fertilizer? Take a look at your multivitamin for humans. Are all the vitamins present in the exact same quantity? Of course not. It is well known that if a human consumes an equal amount of Vitamin D, as Vitamin C, and was taking the near 1000mg of C recommended, the 1000mg of D would over the course of 2 months accumulate and cause severe health issues for the average person, and may cause death in people with risk factors. A multivitamin with a 10-10-10 ratio of the nutrients is NOT BALANCED for humans. What does this have to do with plants? Plants, and I mean pretty much ALL plants, including bonsai and orchids and seaweed and your lawn out front, all plants use nutrients in the ratio roughly 12-0.8-4 with Calcium at 13, Magnesium at 4, Sulfur at 2 and then the long list of Micronutrients. Reference - "What do Orchids Eat" by R. Lockwood 2013, this article is about orchids, but the references cited lead to the all plants statement.

So based on the article cited, and the many references cited in that article, a 10-10-10 or a 20-20-20 fertilizer is NOT BALANCED. Indeed, a 12-1-4 fertilizer is what is truly balanced. This 12-1-4 not considered high Nitrogen, this is actually a "just right" for Nitrogen. High nitrogen fertilizer would be something like a 30-1-30, which, quite honestly, we just don't see on vendors shelves. So the reality is, you have never seen an off the shelf fertilizer that is truly a high nitrogen fertilizer. Except for the single component nutrients such as Calcium Nitrate sold in the higher end hydroponics shops at huge mark up for the marijuana market. So a Balanced fertilizer is roughly 12-1-4, this is key for understanding fertilizer.

That is item one. I'll respond to later posts below.

A short list of fertilizer references is available on my website under the heading, "Fertilizer Information".

leosorchids.com

www.leosorchids.com

 

[Leo in N E Illinois]

Great info. Ok I'll keep fertilizing it like everything else then. It's a little relieving knowing that this element of growth is largely out of my control, truthfully.

The one factor that people seem to agree on is the temperature: a colder, harder freeze yields better flowers on many fruiting trees.

@0soyoung - is correct

Next statement, that "harder freeze yields better flowers on many fruiting trees" this unfortunately is almost completely false. It might be true if you were writing a gardening book for northern Georgia. But no book for agriculture, or horticultural science would ever make a statement like that, because there are so many exceptions, that the exceptions outnumber the "true" occurrences. So throw this one out with the 10-10-10 is balanced myth.

In my opinion, the biggest insult I will offer is to refer to information being worthy of a "gardening book". Gardening books are "soothing" and have no science content. Agriculture, and horticulture are sciences, and not soft sciences. These two are are hard core scientific fields that are just as dependent on higher mathematics as physics. or engineering. No farmer still in business today uses "gardening books" to produce their crops. Fact based, scientific information is used by the modern farmer, and it is high time bonsai made an effort to "catch up". throw out your gardening books, and start reading Agricultural and Horticultural science based books, website and information. Yes, some gardening books have pretty pictures, and I like pretty pictures. But not for learning how to grow bonsai.

@Mycin - I'm not picking on you, you happen to be asking the right questions to get these answers. My friend @coh , Chris, has been asking me to write of a full blown fertilizer article for publication. These rave outs are trial runs for the future "book length" article.

 

[Leo in N E Illinois]

I guess Superthrive is a moneymaking scheme never scientifically proved to work with bonsai.

"Super Thrive" is one of many "magic elixirs" sold to the unsuspecting public. As far as I can tell, the only science around Super Thrive shows it has no effect. But it is cheap enough. Use it if it makes you feel better about your plants. Nobody so far has "proven" beyond anecdote that Super Thrive does anything at all.

If you want an elixir that does work, does have benefit, add a humic acid solution, especially any solution that has both humic and fulvic acids. Many of the seaweed extracts have these 2 components. There is a nice article showing the benefits of humic and fulvic acid acids on blueberry crop yields. I need to find my copy and post it. Point is, seaweed extracts with fulvic and humic acids are indeed beneficial elixirs. No "snake oil" involved.

 

[Leo in N E Illinois]

Rain, clear water and Potassium.

Potassium, the 3rd number in the fertilizer ratio, is has the greatest water solubility of any of the nutrients required by plants. Potassium is so water soluble that rain, or clear water can leach the potassium out of plant tissues fairly easily. Most of the other nutrients, plants can "hang on to" even after a week or two of daily rain. Potassium, being so mobile, can quickly become a "limiting nutrient" simply by being leached away. On the other hand. In greenhouse and hydroponic situations, where continuous feeding programs are popular, potassium can build up in water reservoirs to excess, and I have personally observed symptoms of excess potassium in my orchids while using a continuous feeding program. Flushing with clear water occasionally, will was away any excesses of accumulating potassium. This is only something to worry about in greenhouse, under lights and other controlled growing situations where continuous feeding and recycling of nutrients is common. A closed system is difficult to keep exactly correct.

Why is there so much Potassium (K) in so many formulations?

This is because the source of N, nitrogen, actually matters. Plants need nitrogen, and they need more nitrogen than any other nutrient. The source of N matters. Plants can absorb N in the form of ammonia, or ammonium ion, directly, expending zero metabolic energy (sugars) to do so. Plants can also absorb N in the form of amino acids, again using little or no metabolic energy. I'm not totally clear if some energy or not is required, but it is certainly not a large amount of energy. Plants can absorb nitrate ions, NO3, but require active metabolism to absorb nitrate. This requires burning sugars to absorb nitrates. A significant part of a plants daily sugar manufacture can end up going into energy to fuel the absorption of nitrates. I've seen reports that as much as 50% of the daily photosynthetic production can go into absorbing nitrates. I don't think it is always as high as 50%, but in least one study this was the case. In the active chemical process of absorbing nitrates, potassium is consumed. Rough 2 ions of K for every ion of N will be consumed when absorbing, or metabolising nitrates. This is the reason that NITRATE based fertilizers have roughly equal N and K numbers. Note: Potassium, K, is reported on labels as K2O - dipotassium oxide. This is a quirk of USA laws governing fertilizer labels. The USA rules do not hold world wide. So on a label in USA where it says 12-1-4, the real number for the K =8, because the 4 represents dipotassium oxide.

 

[coh]

@0soyoung - is correct

@Mycin - I'm not picking on you, you happen to be asking the right questions to get these answers. My friend @coh , Chris, has been asking me to write of a full blown fertilizer article for publication. These rave outs are trial runs for the future "book length" article.

Go Leo! Would love to see you put all your years of experience into an article. I'd actually like to see Paul from Australia do that too (I think he was @63pmp , haven't seen him in a while) as he seemed to be very knowledgeable on the subject.

Is that K-lite fertilizer still available? I haven't been to rays website (I think that's his name) in a while. Was going to give it a try but never got around to it. I note that in some of the recent Mirai podcasts dealing with the manure tea, they've talked about the fact that akadama is naturally high in phosphorus, I think - and that perhaps we are creating problems when we use "balanced fertilizers" that have relatively high P. At least for those of us using akadama. Another issue they talked about is the need for more calcium than most fertilizers have. It's such a complex topic, I hope to devote more time to it this winter while my trees are sleeping.

 

[Bnana]

There is a lot of hogwash about fertilizer sloshing around on bonsai forums and in bonsai books. It would be very good if there would be a more scientific source.

Plants can absorb N in the form of ammonia, or ammonium ion, directly, expending zero metabolic energy (sugars) to do so.

This is true of course but plants have a hard time keeping ammonia out if it's in the soil in high concentrations. They can waste a lot of energy keeping it out. How they do that differs between species.
Furthermore NH4 and NO3 are also oxidised/reduced in the soil so in the end it might not be what you had in your watering can.

 

[Leo in N E Illinois]

So if all these old fertilizer formulations are so bad, why aren't my trees dead yet? In fact, some look pretty darn good?

This is the question thrown to me the first time I was paid to give a fertilizer talk to a bonsai society. It derailed the entire talk, demoralized me, because the person who asked, had bonsai of sufficient quality that he had one or two that were donated to the National Bonsai Collection in D.C and the Pacific Rim Collection, and he had authored a bonsai book. Jack D. knew of what he spoke, and he could prove it with top quality trees.

So if all these older fertilizers are so bad, why do some trees, maybe even your own trees, look so good?

The answer is actually simple. RAIN. Flushing with clear water, or rain, washes away many of the excess nutrients that we so liberally mis-apply. Rain will actually leach out nutrients that are not chemically bound up in a leaf or a tree. This is done by simple diffusion processes. Leaves are not that thick, mere hundreds or low thousands of cells from the axial to abaxial surfaces (upper to lower). This is a short enough distance that diffusion is a significant factor. The leaf can loose nutrients very directly, also the roots will loose nutrient to relatively pure rain water flowing past the roots. So in the case of the unbalanced 10-10-10 fertilizer the excess phosphorous is simply washed away. For most nutrients, plants have a mechanism for hanging on to some of the essential nutrients, potassium is the only nutrient that can get leached away by rain to a sufficient degree that short term deficiencies can develop. Nitrogen deficiencies are the most likely to show first, and will the be deficiency we most frequently recognize, as it is the second most soluble nutrient, second only to potassium. Also, because use of nitrogen, especially nitrates, depends of the presence of potassium, a deficiency of potassium will often present as a nitrogen deficiency, at least in the case of mild potassium deficiencies.

Summary, RAIN will wash away your sins of fertilizer mismanagement. (Note: this is meant to be an attempt at fertilizer humor)

So why would you need to change your fertilizing practices?

First - efficiency. It is wasteful to dump excess fertilizer on our trees and have large parts of it wash through to our lawns, without being used.

But the "bad fertilizers" are cheap, why not?

Urban and suburban run off are major contributors to eutrophication of our lakes and streams. For example, in 1975 Madison, Wisconsin, a study of nitrogen sources into Lake Monona, a medium size inland lake that is totally surrounded by urban and suburban development, dog manure left on the lawns, contributed to roughly 25% of the total nitrogen being transported to Lake Monona for the entire year. No shit !!! The lake had become unpleasant for swimming due to algae blooms, so the study pointed out that something that in the 1970's was considered "trivial", dog poop on the lawns, actually was a significant source of the nitrogen making the lake unfit for swimming. Now are there enough individual bonsai benches leaking excess phosphates into our surface waters to make a difference? One can argue it doesn't matter, but if one is trying to live more softly on the land, every little bit helps.

If we can get our fertilizers more in line with what plants actually use, we will stress our plants less, feed them better and live more softly on the land.

 

[Leo in N E Illinois]

There is a lot of hogwash about fertilizer sloshing around on bonsai forums and in bonsai books. It would be very good if there would be a more scientific source.


This is true of course but plants have a hard time keeping ammonia out if it's in the soil in high concentrations. They can waste a lot of energy keeping it out. How they do that differs between species.
Furthermore NH4 and NO3 are also oxidised/reduced in the soil so in the end it might not be what you had in your watering can.

Absolutely true. Somewhere around 40 ppm as ammonium ion is the beginning threshold for the most sensitive species. Majority of trees and shrubs used for bonsai have a greater tolerance above 40 ppm. If the trees or shrubs will tolerate upwards of 200 ppm that is sufficient to make use of ammonia, or ammonium ion plausible as a nutrient solution. We do not need to go all the way to 1000 ppm as N, that is a concentration for "forcing growth" as in the "tomato patch", rather than controlled growth required for bonsai. Lower concentration of fertilizer solutions, applied more frequently would allow for use of ammonia and or ammonium ions as the nitrogen source.

Good air void structure to the bonsai potting medium means oxygen is present in the root zone, this allows rapid oxidation by soil microbes of ammonia into various nitrous oxides, such as NO, and NO2, and NO3, so oxygen in the potting media does help prevent ammonia toxicity. With good air voids in the mix, the relatively low 200 ppm as N concentrations we are discussing, are fairly safe.

Fish emulsion and other protein sourced fertilizers, rely on nitrogen available in the form of amino acids, and the tolerance for amino acids in the irrigation water seems pretty high.

 

[Leo in N E Illinois]

Got a lot more I could say, but I need to go outside and get some air. My fingers are tired of typing. I bet my "dear readers" are tired of reading.

More later.

 

[Leo in N E Illinois]

Go Leo! Would love to see you put all your years of experience into an article. I'd actually like to see Paul from Australia do that too (I think he was @63pmp , haven't seen him in a while) as he seemed to be very knowledgeable on the subject.

Is that K-lite fertilizer still available? I haven't been to rays website (I think that's his name) in a while. Was going to give it a try but never got around to it. I note that in some of the recent Mirai podcasts dealing with the manure tea, they've talked about the fact that akadama is naturally high in phosphorus, I think - and that perhaps we are creating problems when we use "balanced fertilizers" that have relatively high P. At least for those of us using akadama. Another issue they talked about is the need for more calcium than most fertilizers have. It's such a complex topic, I hope to devote more time to it this winter while my trees are sleeping.

Thanks Chris
Yes, I do have both the K-Lite MSU formulation, which indeed contains Calcium and Magnesium in macronutrient quantities, ideal for people watering with collected rain water or indoors with RO or DI water systems. Originally designed for Orchids in a continuous feeding program.

I also sell a ZERO Calcium fertilizer developed for specifically Blueberries (by MSU), but is the ideal ericaceous plant food, other wise known as Acid Plant Fertilizer. It is a 11-2-6, and I use it on the blueberry farm and for my orchids

I'll put an add up in Market place, but until I do so, you can PM me for details.

 

[Forsoothe!]

Some of us prefer to stay on the low side of fert application in order to grow small, compact plants.

 

[Mycin]

Ok lots of great stuff to take in and digest from Leo I don't disagree with anything you've posted but I will defend my choices for the sake of discussion:

1) I know that the uptake of nitrogen from nitrates is quicker than urea and ammoniacal nitrogen sources. As you mention, these fertilizers are flushed out with each watering so I sought out a fertilizer with a high proportion of nitrates to ensure that my trees get the nitrogen. The only high nitrate fertilizers from JR Peters are their professional line of fertilizers, which are only available in huge bags. I would have preferred their 25-5-15 or even 20-10-20, but the only one that seems to get bagged up and sold in 1-2lb sizes is the 20-20-20. I know it's not optimal but it seemed like the best option to me. Honestly, I always thought MSU formulas were Orchid specific.

2) As for the cold winter = better fruits/flowers, that could well be a myth but it hasn't really been studied to prove or disprove it--at least as far as my cursory literature search showed. A few local growers have mentioned it to me, but what made me believe was Brent Walston--of whom I am a huge fan--indicated as much when we spoke via email. I may well have misunderstood him, I don't want to misquote or misattribute any ideas to him. But he always seems to take a scientific approach to his growing and has tons of experience growing flowering & fruiting trees

I'll follow up to see if he's willing to explain the mechanism behind the proposed idea.

 

[Leo in N E Illinois]

@Mycin - again, you are commenting on the right things. So I'll comment, I'm not trying to drown you in information, though it will be a lot.

1 - There is a bit to unpack in your first point. You got the uptake and solubility a little bit wrong, not a big deal but knowing what is actually happening helps. First, ammonia, and ammonium are absorbed more quickly than any other form of nitrogen, at no cost to the plant. Amino acids are in 2nd place for speed of absorption. Nitrates are in third place, and require significant energy output by the plant. There is a cost to absorbing nitrates. Fourth, is urea. Here you are correct, urea is the slowest. The reason urea is slow in uptake is that it is a 2 step process. Urea requires soil microbes to break down the urea into ammonium ions and nitrate ions. The ammonia and ammonium ions are absorbed very rapidly (after bacteria break up the urea) and then the nitrates are absorbed at a slightly slower rate because active metabolism has to get involved to bring the nitrate into the roots (or leaf if foliar feeding). The rate at which nutrients get flushed out of a plant by rain or clear water is pretty constant, with potassium moving more rapidly. Nitrogen, regardless of type, nitrate, or ammonia, move at a rate slower than potassium. Phosphorous is the one nutrient plants are "best" at hanging on to. Not as much phosphorous leaks out of a plant, once surplus phosphorous has dissipated. This leaching is not "total" with a single watering, some moves every time the plant is watered. It is just a fact and choice of nitrogen source does nothing to significantly change the rates of flushing.

The good thing about flushing, is it allows you to use terrible badly formulated fertilizers, and not kill your plants. Your fertilizer does not have to be as carefully formulated, rain will wash away the excesses.

Why are "professional" fertilizers the only fertilizers to use mostly nitrate? Its not because nitrate is better for the plants. It is because professional fertilizers include calcium and magnesium as macro-nutrients. You can not make a water soluble nutrient solution with calcium and any sulfur compound. Calcium and sulfate become an insoluble powder that plugs up sprayers and injectors and makes a layer of calcium sulfate rock - also known as gypsum, in the bottom of your container. If you are making fertilizer, and you add ammonia, the safest way to add ammonia is as ammonium sulfate. But you can not use ammonium sulfate with calcium formulas, because the calcium and sulfate will sludge up the solution. Ammonium nitrate is often avoided as it require more careful handling, as in its dry form, it can be explosive - think fertilizer bombs. So the reason professional grade fertilizers use nitrates is because its the only way to get calcium into a water soluble solution.

About MSU for Orchids - I shared a meal with Jan Szryn, she developed MSU Orchid fertilizer. She made it clear that the MSU for Orchids was a "minor market" afterthought. It is basically the MSU - Plug Special, designed for the potted plant trade, for cuttings and seedlings being grown in inert media. The "Plug Special" formula was designed for those mass producers of bedding plants, a big market in Michigan. Orchids are not a very large dollar market in Michigan, so the Orchid formulation came late in their priorities.

Of the two fertilizers I carry, The MSU K-Lite is a variation of the "Plug Special", or the MSU Orchid formulation which includes Calcium and Magnesium, and the Nitrogen comes entirely from Nitrate. The Blueberry Special has ZERO nitrate, it does contain Sulfur and gets 100% of its Nitrogen from ammonium sulfate. Sulfur is an essential nutrient, so the sulfate is a good thing. I really recommend alternating between the two fertilizers.

Item 2 - ah, if your source of the thought was Brent Walston, it makes sense, and for him, growing winter hardy trees in California, his issue is indeed that his winters are not cold enough. I'm running a small blueberry farm in Michigan, where we have to worry about winters being too cold. You know why blueberries are not a big crop in California? Its too warm there. They can only be grown at elevation where it gets cold enough. But in Michigan, it is very possible to have a winter that is too cold. The winter of 2012-2013 in Michigan had a late season cold snap that completely destroyed the cherry, apple and grape crops, ruined 3/4 of the blueberry crops and otherwise cost the state fruit industry more than 50 million in losses that year.

Best way to consider winter chill requirements is species by species. Every tree species has a slightly different requirement. The economic crops, like apple, cherry, grape, and others there is plenty of Ag research that outlines the exact need. For the non-economic species, we just make guesses from related species that there is data about. But really, you just need to learn the individual needs of each of your species. The majority will have their needs overlap, you will be able to keep most of them happy. But it is a species by species thing.

 

[Forsoothe!]

After rereading this again, I think it is the length of a winter that is important rather than more depth of cold which can be counter productive, separately. It occurs to me that this increases the length of the rest period which may be helpful, both regenerative and/or longer bud-building, maybe alternatively year-to-year. I can't think of any stone fruits which don't mature early enough to have a problem with a shorter growing season. Apples I'm not sure one way or the other. Almost all trees have a fruitful year followed by a less fruitful year, back-and-forth, which is a product of the exhaustion of a large crop, having nothing to do with anything here.

Leo?

 

[Trueblackpercula]

This has to be one of the best threads I have read on feeding.

Wow is all I can say

Thank you @Leo in N E Illinois

 

[NateDav]

@Mycin - again, you are commenting on the right things. So I'll comment, I'm not trying to drown you in information, though it will be a lot.

1 - There is a bit to unpack in your first point. You got the uptake and solubility a little bit wrong, not a big deal but knowing what is actually happening helps. First, ammonia, and ammonium are absorbed more quickly than any other form of nitrogen, at no cost to the plant. Amino acids are in 2nd place for speed of absorption. Nitrates are in third place, and require significant energy output by the plant. There is a cost to absorbing nitrates. Fourth, is urea. Here you are correct, urea is the slowest. The reason urea is slow in uptake is that it is a 2 step process. Urea requires soil microbes to break down the urea into ammonium ions and nitrate ions. The ammonia and ammonium ions are absorbed very rapidly (after bacteria break up the urea) and then the nitrates are absorbed at a slightly slower rate because active metabolism has to get involved to bring the nitrate into the roots (or leaf if foliar feeding). The rate at which nutrients get flushed out of a plant by rain or clear water is pretty constant, with potassium moving more rapidly. Nitrogen, regardless of type, nitrate, or ammonia, move at a rate slower than potassium. Phosphorous is the one nutrient plants are "best" at hanging on to. Not as much phosphorous leaks out of a plant, once surplus phosphorous has dissipated. This leaching is not "total" with a single watering, some moves every time the plant is watered. It is just a fact and choice of nitrogen source does nothing to significantly change the rates of flushing.

The good thing about flushing, is it allows you to use terrible badly formulated fertilizers, and not kill your plants. Your fertilizer does not have to be as carefully formulated, rain will wash away the excesses.

Why are "professional" fertilizers the only fertilizers to use mostly nitrate? Its not because nitrate is better for the plants. It is because professional fertilizers include calcium and magnesium as macro-nutrients. You can not make a water soluble nutrient solution with calcium and any sulfur compound. Calcium and sulfate become an insoluble powder that plugs up sprayers and injectors and makes a layer of calcium sulfate rock - also known as gypsum, in the bottom of your container. If you are making fertilizer, and you add ammonia, the safest way to add ammonia is as ammonium sulfate. But you can not use ammonium sulfate with calcium formulas, because the calcium and sulfate will sludge up the solution. Ammonium nitrate is often avoided as it require more careful handling, as in its dry form, it can be explosive - think fertilizer bombs. So the reason professional grade fertilizers use nitrates is because its the only way to get calcium into a water soluble solution.

About MSU for Orchids - I shared a meal with Jan Szryn, she developed MSU Orchid fertilizer. She made it clear that the MSU for Orchids was a "minor market" afterthought. It is basically the MSU - Plug Special, designed for the potted plant trade, for cuttings and seedlings being grown in inert media. The "Plug Special" formula was designed for those mass producers of bedding plants, a big market in Michigan. Orchids are not a very large dollar market in Michigan, so the Orchid formulation came late in their priorities.

Of the two fertilizers I carry, The MSU K-Lite is a variation of the "Plug Special", or the MSU Orchid formulation which includes Calcium and Magnesium, and the Nitrogen comes entirely from Nitrate. The Blueberry Special has ZERO nitrate, it does contain Sulfur and gets 100% of its Nitrogen from ammonium sulfate. Sulfur is an essential nutrient, so the sulfate is a good thing. I really recommend alternating between the two fertilizers.

Item 2 - ah, if your source of the thought was Brent Walston, it makes sense, and for him, growing winter hardy trees in California, his issue is indeed that his winters are not cold enough. I'm running a small blueberry farm in Michigan, where we have to worry about winters being too cold. You know why blueberries are not a big crop in California? Its too warm there. They can only be grown at elevation where it gets cold enough. But in Michigan, it is very possible to have a winter that is too cold. The winter of 2012-2013 in Michigan had a late season cold snap that completely destroyed the cherry, apple and grape crops, ruined 3/4 of the blueberry crops and otherwise cost the state fruit industry more than 50 million in losses that year.

Best way to consider winter chill requirements is species by species. Every tree species has a slightly different requirement. The economic crops, like apple, cherry, grape, and others there is plenty of Ag research that outlines the exact need. For the non-economic species, we just make guesses from related species that there is data about. But really, you just need to learn the individual needs of each of your species. The majority will have their needs overlap, you will be able to keep most of them happy. But it is a species by species thing.

Leo,

You are a fountain of knowledge, thank you for incredible insight. I have been wondering and performing literature reviews for answers such as the ones you have provided. All of my research has been review of agricultural studies. My question for you is... Do you think that the extrapolated NPK of 12-1-4 translates 1:1 to the bonsai container?

Would this NPK ratio possibly impede bud and flower production? Would it create excessively long internodes? I would assume here that the source of nitrogen would be the real issue.

Would the plants become anemic over time given that many modern substrates are largely inert? Each watering flushing out the most soluble forms of macro and micro nutrients. The source of water would obviously be another important variable, tap vs rain vs RO vs RO re-mineralized and etc.

Given all this, hopefully, you can provide me further insight. I utilize two different mixes for my bonsai. My mix for trees entering refinement is 2 parts lava, 1 part pumice, 1 part expanded shale, 1 part turface (because it's acidic and I bought a lot a very long time ago), 10% clinoptilolite based on volume (used for is CEC, buffering, water holding capacity). The next mix is the same just add pine bark at 1/4 to 1/2 by volume as my grow mix for developing material.

I consider all aggregates used to have poor nutrient holding capacity except pine bark and zeolite/ clinoptilolite. Due to the behavior of my soil I have settled on dry organic fertilization in conjunction with liquid fertilization and tap water acidification.

Would a dry 8/6-2-3 organic fertilizer with an organic liquid 4-2-3 yield the long term results sought we seek in bonsai? In my mind, robust growth with short internodes and dense ramification that is stress/disease/pest resistant. I have gone through many fertilizer regimens over many years and am now looking to simplify it so with the following...

What are your thoughts on these?

 

[63pmp]

I

The traditional wisdom suggests that flowering trees will yield optimal blooms when fertilized with a low nitrogen fertilizer towards the end of the summer, through fall. The explanation provided is that higher nitrogen will result in more vegetative growth and less flower budding. I would have chalked this up as an old wive's tale, but I've heard it repeated by more than a few respected bonsai growers. On the other side, I'm hearing more and more people say that next year's buds are being grown now and high nitrogen will help these very buds develop. Not quite sure what to think.

Right now I'm using Peters 20-20-20 and would prefer not to buy a seperate "bloom promoter" fertilizer for my one Chaenomeles but if that's what would be best I'll do it. FWIW the Chaenomeles is developed, I'm just looking for maximum fruits, flowers, and ramification--in that order

I think to improve flowering you need to feed N in autumn. Deciduous trees will store what they need to support 3 or 4 new leaves, in spring, to maturity, the plant will then need supplementary N for any extra new growth. I would recommend watering/fertigating with a weak K and Mg solution a month or so before flowering as roots are active before bud burst. K is essential for proper flower development. If your trees are established then they do not need much N. How much depends on where you live and the plant you are fertilizing. The Japanese bonsai growers suggest little fertilizer in spring more in summer and most in autumn. As they seem to feed mostly with organic pellets you will have to fit that in with your choice of fertilizer.

 

[Forsoothe!]

I feed my landscape with chemical/inorganic ferts & conditioners in autumn because they need to break down and dissolve into the soil to become usable and that takes time. I want them available in the following spring as the plant wakes up and begins to need them. The whole thing is a sporadic process with not much happening while the soil is frozen or near freezing and increasing from minutes per day when things warm in the daytime sun and cool over night. Microbes and plant roots turn on and off with the temperature as if it was on a dimmer switch. The ferts don't really become available in autumn because it takes time to dissolve and by the time that happens the roots and microbes are quiescent. But everything is ready, willing and able to take off in spring.

Supposedly, feeding too early in spring begets plants that grow too early and get frost damage. That assumes that plants respond to ferts by growing when they shouldn't. If it were possible to fool plants into growing when they shouldn't, we could force them to grow longer in autumn just by over-feeding them. That doesn't wash. Frost is unpredictable from year-to-year and the plants that get caught are predominantly those that are grown out of their range, having nothing to do with the fertility of the media. The same logic applies greenhouse plants because protected from winter is one thing, but the warmth, intensity and duration of sunlight is more important than anything else as a governor of growth.

Trees in pots need a gentler fert program because pots are apt to warm up much more quickly in spring. I keep them on the ground longer than anybody else I know, and hate every extra minute. But putting them on the bench too early is exactly like growing species out of zone and getting them zapped by frost. My trees are not in Dayton, Ohio and putting them on the bench on a nice spring day in late April when the guys down south do is inviting a problem I want to avoid. So, I feed them in spring when I put them on the bench in the first week of May which is my traditional time to plant tomatoes in my garden. The soil is the right temperature to immediately use the commercial liquid and all is well.

 

[BrianBay9]

"Super Thrive" is one of many "magic elixirs" sold to the unsuspecting public. As far as I can tell, the only science around Super Thrive shows it has no effect. But it is cheap enough. Use it if it makes you feel better about your plants. Nobody so far has "proven" beyond anecdote that Super Thrive does anything at all.

If you want an elixir that does work, does have benefit, add a humic acid solution, especially any solution that has both humic and fulvic acids. Many of the seaweed extracts have these 2 components. There is a nice article showing the benefits of humic and fulvic acid acids on blueberry crop yields. I need to find my copy and post it. Point is, seaweed extracts with fulvic and humic acids are indeed beneficial elixirs. No "snake oil" involved.

I did an experiment with superthrive when I was working with a bonsai nursery and had enough plants to make it worthwhile. Used several species of trees, at least 30 plants per group, and tested only one of the hundreds of claims that Superthrive makes on it's label - stimulation of roots and inhibition of transplant shock. I've described it on the site before, but the bottom line was there was no difference between treated and placebo groups with all species EXCEPT for JBP. In that case the Superthrive group had a statistically significant increase in plant death. I should also note that JBP were the only conifer used in the experiment.

 

[Clicio]

.. EXCEPT for JBP. In that case the Superthrive group had a statistically significant increase in plant death. I should also note that JBP were the only conifer used in the experiment.

Ouch! Do they warn the community on their so famous label?