Fertilize heavily???

[WNC Bonsai]

I often see folks recommend fertilizing heavily, however I cannot remember any posts or videos that actually define what they mean by “fertilizing heavily”. Does it mean double or triple up on the amount of fertilizer when you normally fertilize? Does it mean you should fertilize twice as often or do both? What about when it comes to organic vs inorganic fertilizers and liquid vs dry applications. I think the most definitive description was from Walter Pall who says he uses 20-60 times more than most bonsai growers, but that is his normal application rate! So if you fertilize heavily how about sharing just what you mean by that and also when you feel it is appropriate to do it. Below is from Walter’s website:

How much? WAY MORE THAN YOU THINK! I feed from 20 to 60 times more than the average bonsai grower. From the beginning of April to the middle of October, every ten days everything is fed with liquid fertilizer, using three to four times the suggested dose. All trees are fed equally, whether deciduous, conifers, small, large, repotted, collected or not. This is a span of about 200 days when the trees are being fed. Since the trees are fed three times the normal dose on twenty days in that time, it makes for 60 doses of fertilizer in the growing season. The average bonsai grower feeds maybe three or five times at half the normal dose because 'bonsai trees should not grow'. If you then add two times a year of chicken manure being given to the trees, you can then understand why this schedule is 20 to 60 times more than the average.

 

[shohin_branches]

For me it means I have a few bags of slow release fertilizer on the soil surface and I also water with full strength liquid fertilizer once a week.

 

[Wires_Guy_wires]

I use cow manure mixed with chicken manure.
For every coffee mug of soil, I use two tablespoons of fertilizer per application. Once or twice or none in spring, twice in summer and twice in fall.
Heavy is doing it more often; reapplying it every 6 weeks during any growing season.

I add a teaspoon of seaweed every summer and every spring.

These amounts are estimates, depending on what I want from the plant. If I want it to slow down, I only do late summer and fall fertilizing. If I want heavy growth, I do it all, and see how the plant responds.

It's always better to underdose. One overdose means death. So don't double the amounts, just double the timing.

 

[eugenev2]

I often see folks recommend fertilizing heavily, however I cannot remember any posts or videos that actually define what they mean by “fertilizing heavily”. Does it mean double or triple up on the amount of fertilizer when you normally fertilize? Does it mean you should fertilize twice as often or do both? What about when it comes to organic vs inorganic fertilizers and liquid vs dry applications. I think the most definitive description was from Walter Pall who says he uses 20-60 times more than most bonsai growers, but that is his normal application rate! So if you fertilize heavily how about sharing just what you mean by that and also when you feel it is appropriate to do it. Below is from Walter’s website:

If i'm not mistaken, Walter pall's approach is also based on complete inorganic and multiple waterings a day. So you need to provide the same condition and same care to follow the same approach.
My version of heavy fertilizer is solid organic fertilizer which is guano and seaweed based pellet, every 3 weeks as per the label. And then fish emultion at half strength every week for my slow growers and full strength for my black pines. But i guess "heavy" is relative

 

[River's Edge]

It Depends!
Some important clarifications with respect to fertilization. Be accurate in understanding the strength of fertilizer used and its availability to the plant!
For me heavy fertilization is making sure that fertilizer is readily available in consistent amounts as desired for the situation.
Always take the time to increase dosage slowly if wishing to provide heavier doses!
As a matter of course I typically refrain from Higher numbers than 10 for NPK, prefer organic with wide range of micronutrients and beneficial microhyzae / bacteria included. Like to use a variety of products and tend to underdone and be more continuous with a program. The exception being during advanced development and refinement.

 

[Dav4]

Yeah, I think the phrase "fertilize heavily" is a bit vague and I'm not so sure there's much upside to overfeed a tree in a pot. I think a better phrase might be "fertilize consistently". I always have some kind of solid organic fertilizer on the soil surface during the growing season, with more on young, developing trees and less on older and more developed trees. I also apply liquid fertilizers like dyna-gro and fish emulsion every 1-2 weeks all season long. In my yard, trees getting fertilized heavily have lots more solid ferts on their soil and might get a few extra servings of Dyna-gro during the summer.

Fwiw, I believe W.P. no longer feeds 3-4x the advised fert strength like he did years ago, as I believe some of his older, collected evergreens didn't enjoy it year over year.

 

[Mats Hagström]

This year I over fertilized with chemical fertilizer and all the leaves fell off several trees. I think we can safely add lots or organic fertilizer but with inorganic we should really be adding it to our weather and measure the particle content. For the trees I over fertilized I rinsed the soil a few times and will be more careful in the future. I think conifers are a bit more resilient but I know Jonas Dupuich has had fertilizer needle burn on pines.

I feel pouring on fish emulsion is safe but prefer more dilute and more frequent addition of inorganic.

 

[Shibui]

Don't use higher concentrations of liquid fert. Some recommended strengths are conservative so stronger might be safe but for some, increasing the mixing rate may be too strong. That's where the strength can get to killing roots stage.
More often is usually OK. The recommendation on the container are meant for normal potted p[lants which might be watered every week or so. Because we water more, which leaches nutrients out of the pots, we can apply recommended strength fert more often that recommended.
Liquid fert every week or 2 is usually OK.

 

[defra]

I fill paper tea bags with spaghmum Moss and 2 teaspoons of fertelizer pellets from dcm and depending on how big the pot is i put between 4 to 8 of them on the pot with a wooden toothpick to keep them pinned down from spring till summer at hottest time of year i usualy stop and continue late summer till fall.
I replace the bags every 3 weeks because then the pellets are mostly gone so each watering some of the fert goes in the soil but some will come out at the bottom also i use propper soil that has good drainage.
Some trees will get some extra magnesium every once in a while.
Most of my trees need allot of growth so i can fertelize heavy but once refining the pads i can reduce the ammount of fertelizer used.

On a side note i use a little bit of zeolite in my soil and zeolite can hold and bind the nutriënts that go in the pot and the tree can take them as needed.

 

[Ininaatigoons]

So far pretty sane responses. Is there still any debate on cutting or keeping nitrogen balanced throughout the fall? I'm still a little afraid of trees not wanting to go to bed for winters nap. Any recommendations on levels of nitrogen would be appreciated.

 

[defra]

So far pretty sane responses. Is there still any debate on cutting or keeping nitrogen balanced throughout the fall? I'm still a little afraid of trees not wanting to go to bed for winters nap. Any recommendations on levels of nitrogen would be appreciated.

I am no pro but manage to keep my trees happy the past years ofcourse made mistakes and lost some in the learning curve but i basicly use the same fert for all my trees some i wait till they have flowered but other then that no different treatments.
I am aware that some fertelizer is low on nitrogen for fall fertelizer but the way i see it in the ground the tree takes what it needs while other things are in the ground also it use nitrogen to grow but if the tree stops growing and goes dormant the roots will not take it up and the remains slowly get washed out at least so far i have never had problems doing it like this but i think its an interesting discussion so looking forward to gear others about this

 

[Shibui]

Trees respond to the seasons rather than nutrient availability. Otherwise every plant close to a nitrogen source would not shut down for winter.
Low N fall fertilising is more to do with encouraging flowers next spring than winter hardiness. From around the end of Summer, flower embryos are forming in spring flowering species. lower N:K ratio at this stage seems to promote more, stronger flowers next spring.
I change to a lower N, higher K fertiliser (flowers and fruit, rose, azalea, tomato ferts are all good) soon after mid Summer and continue to leaf fall.
Non flowering species still get standard fert right through to leaf change of colour.
Non flowering evergreen species get some fert right through our mild Winters as they never seem to go completely dormant here.

 

[Paradox]

Going to low nitrogen fertilizers in the fall has been pretty much deemed as not necessary from everything Ive seen on it in the last 10 years or so

 

[WNC Bonsai]

My personal take on this is that there are so many different variables when it comes to fertilizer application that recommending someone fertilize heavily without fully discussing these variables is not a responsible thing to do. Walter Pall’s approach was predicated on coarse inorganic soil and lots of water, so much of what he applied as liquid fertilizer flushed right on through the pot and ended up on the ground. However it sounds as though he may have modified that now (but he still has it on his website). In my case I don’t increase the amount of fertilizer but instead increase the frequency of application. Applying an overly strong nutrient solution may create a harmful osmotic potential and kill sensitive root hairs. I also water before applying fertilizer and that way I don’t immediately flush out what I just applied, plus I do it immediately after watering. That way the roots have a 24 hour window of opportunity to take up the nutrients and for some to end up on exchange sites in the soil.

 

[Deep Sea Diver]

Here’s my take…

Feeding heavily merely means applying the maximum amount of nutrients a plant can accept consistent with keeping the plant in good health. But there is a twist as this looks different (I.e. nutrient load) for a plant in development and one in ramification…

Two ways to do this…. looking at the most simplified view

1. Lower the number of days between intervals while maintaining the usual dose of nutrients..

2. Increase the amount of nutrients, while using the same interval.

Both depend on the hobbyist having a good knowledge of the maximum nutrient load as plant can accept safely considering the health and species of the plant being dosed and the type of nutrients used.

Obviously the use of standard old school organics are easier to master. However with the advent of the new wave of organic nutrients.

Three years ago Walter Oak wrote this to me.

“I have cheged d. Fertilization. learn about your tree species and requirements and fertililize accordingly. Some want a lot some much less. It depends. With some substtqtes you can over-fertilize. So be careful.”

So the upshot is one needs to have a

Cheers
DSD sends

 

[crab apple]

I wonder if one could add a little fert to a rain barrel, that way every time you watered they'd get a little fert. Probably have to keep it stired up.

 

[YoungGrampa]

Just happened to find this video yesterday.

 

[WNC Bonsai]

I wonder if one could add a little fert to a rain barrel, that way every time you watered they'd get a little fert. Probably have to keep it stired up.

Nigel Saunders adds a pinch (literally) of MiracleGro (or its equivalent) to his watering can every time he waters so the trees get a “trickle feed” all the time.

 

[August44]

Just happened to find this video yesterday.

Appreciate the link. The guy repeated himself a bit to much for me...wore me out. Also did not get to see his fertilizer applicator or know which Miracle grow he was using as there are several. Fertilizing every day seems a bit to labor intensive for me. Won't say that his procedures are not correct, they work well for him, but people who have another life would be hard pressed to go his direction.

 

[MaciekA]

Just happened to find this video yesterday.

The above YouTube video comes with an asterisk or "more to the story", which is that students and clients that fertilize like Andrew does are also otherwise doing horticulture like Andrew does and that these things go together. He is potting in certain soils, relying on training in watering & moisture monitoring practices, using pots that are correctly sized for a given tree's root system density/stage of development, waiting for generous extensions to signal strength for work suitability, etc etc. There is a magical horticulture sweet spot that dials in soil + pot dimensions + current root/canopy density + full sun w/ shade cloth adjustment + top dressing + person-always-on-site watering practices. Andrew is able to feed in a way that might cause trouble for a grower who has a young maple seedling in a 15 gallon fabric pot of organic potting soil, on a balcony, in zone 6, etc.

If you fertilize like Andrew does, then ideally you're set up in similar ways with techniques / materials / climate / etc. That is very similar to Walter Pall's situation with the "heavy feeding" comments: If you follow Walter's advice, you should probably be paying close attention to his other practices / climate factors / etc.

Consider that we are confronting an apparently-shocking idea. But then also consider that if you take a close look at what's going on with the successful growers with bushy/healthy trees, a heavy feeding scheme is often linked to some kind of horticultural constraint that gives us the "license" to do that. If their trees are healthy decade after decade, then they didn't over-feed, they heavy-fed a vigorous tree that was ready to take up a lot of fertilizer without any regrets.

An example might be that you hear from a hypothetical Japanese grower: "I can cover this JBP with fertilizer bags because it is in this soil, this container, has this root system layout, this sun exposure, with this large unpruned leader tip, and can therefore handle heavy watering. Also I have seen this work for years". I think it'd be a mistake for the observer's takeaway from this grower to only be "I can cover a JBP with fertilizer bags". Bjorn covered some pond basket JBPs in an ocean of Osmocote once, and when doing so he noted to the viewer that there were constraints that allowed this to be OK in that case, he saw it work in Japan, etc.

Rakuyo is a watering-heavy garden, with strong thirsty trees that have a lot of root mass with respect to container volume, are in soils that drain easily, are never lazy-watered ever (touch the top dressing of every tree to check moisture every time), and with surrounding work practices that allow shoots to form long bushy extensions. It's assumed water will not be sitting still, and if it is, it'll be nudged along and/or the tree will be marked and treated differently. For trees that are in-scope for the scheme of baseline + bonus-if-needed, the assumption is that trees are ready to gobble that fertilizer.

To bring it back to @WNC Bonsai 's original question, the only way I was able to ground myself in terms of knowing "what is actually meant by too much or too little fertilizer and how do I know if the grower is full of shit or not", really the only way, was to connect to growers that were aiming at similar results w/ similar species in my area and actually ask them how much they were using and when, and only ultimately trust growers in my "upstream": The ones that have vastly superior results to mine observed over the longest period of time. I've watched/helped with fertilizer doses get measured out and asked questions. For me this was the best way to get specific details. I could easily see my specific figures or advice screwing up the trees of someone in a growing season half the length of mine, in soils that are dramatically different, with a summer that isn't as wicking-dry as mine, etc.