Growing and fertilizing plants in pots is different than growing and fertilizing plants in the ground. The soil in pots leach out fertilizer with every watering. I think everybody knows that or is aware. That is why we add fertilizer to bonsai.
One day I was reading a gardening article on fertilizer. To my surprise, the article said that plants do not distinguish between molecules of organic and synthetic fertilizers.
Robert Palvis from gardenmyths.com says, “Let’s look at nitrate molecules in more detail. What is the difference between a nitrate molecule from a synthetic fertilizer and an organic fertilizer? The pictures below show the two molecules.
Can you see the difference??
There is no difference. A nitrate molecule from either source is exactly the same. Most importantly plants can’t tell the difference between a nitrate molecule from a synthetic source and a nitrate molecule from an organic source.
I’ll repeat the last sentence since it is one of the biggest gardening myths. There is absolutely no difference between a nitrate molecule from a synthetic source and a nitrate molecule from an organic source.” (http://www.gardenmyths.com/what-is-organic-fertilizer/)
On another gardening website, it said that the reason a gardener should use organic fertilizer is to build up soil structure. The next thought was, why do I need to build soil structure in a soilless bonsai potting mix? The answer: I do not need to. This benefit of organic fertilizer is completely at odds with using “boon mix” type of soils.
It seems the negative thing about synthetic fertilizers is that you have to learn how to use them properly because the margin for error is larger compared to organic fertilizer.
However, If you use organic fertilizer are you maximizing the tree's potential? I would say not.
The paradox is that we put a tree in a pot with soil less potting soil. We bend break and shape the tree. We stunt its growth in a small pot. Then we say oh no, manufactured synthetics are one step too far. That seems counterintuitive to me. To me, it seems that synthetic fertilizers give you more control over how much salts you give the tree relative to the concentration of the dosage.
A quote from sfgate.com, “The nutrients and exact elements available from an organic fertilizer, such as manure or compost, can only be guessed at without laboratory testing. This means you’re giving an inexact application that may or may not meet your plants’ needs. By comparison, applying inorganic fertilizers is simple, because the amount of a given element and the rate of application are known.” (http://homeguides.sfgate.com/inorganic-fertilizer-vs-organic-fertilizer-39528.html)
|Organic Fertilizer pic by F@c@ https://www.flickr.com/photos/16705181@N00/20588210/|
I looked up the big differences between synthetic and organic fertilizers you may have at home.
Organic- Needs organisms to break down, cold slows down the process, Nutrients are at very low levels. It takes longer to break down the organic fertilizer to stuff your plants can use. This prolongs the life of the fertilizer.
Chemical- the Larger margin for error (unless you use the Walter Pal method for feeding). Fertilizer can be used by plants as soon as it is applied. It is cheaper but not as easy to use as organic fertilizer. It is water soluble so it is leached out very quickly.
I'll give you that by using organic fertilizer you will never burn your trees. Here is the thing, we who do bonsai create these impossible tasks related to taking care of bonsai. Here is an example. Some people have a calendar on when to prune candles on Japanese black pine. They say that week one you cut off strong shoots, then week two medium strength shoots, then week three prune weak shoots or something similar. My hero Ryan Neil says that is a bunch of nonsense. He says prune all of the candles back at the same time. Why do we like to complicate our lives? Is it not easier to learn how to properly use synthetic fertilizer? Can we learn what to do so that we use the proper amounts? Won't that help our trees and simplify our lives? I think so.
Here are some quotes from Walter Pal on fertilizing bonsai:
“I use mainly liquid fertilizer that I get from our cheapest general discount market. In America it would be Walmart... 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.”
“Too much salt in the substrate is almost impossible if one waters aggressively every day. Even azaleas don't mind my treatment. They thrive very well with very hard water, ordinary baked loam and peat as the substrate and aggressive feeding like all the rest of the trees.”
Read the whole article here: http://walter-pall-bonsai.blogspot.com/2010/06/feeding-substrate-and-watering-english.html
All in all, if it what works for you is best practice. However, high risk pays high rewards. Cheers.