CRF Fertilizer vs Organic Cakes

I just purchased the book” modern bonsai practice 501 principles of good bonsai horticulture”. It has some great information and I recommend it as another book for your library. In the book the author, Larry Morton, is very pro CRF fertilizer. Does anybody use CRF successfully and if so what brand and how? I understand how CRF works in theory but most posts I see online(bonsainut) seem to be relatively neutral or negative towards CRF. He also states that organic fert, is no better and maybe even not as effective as non organic fert, but I know both Ryan, Lime and multiple podcast guests have stated in the past that they prefer to use organic and see better results. Any thoughts or recommendations for fertilizer this upcoming growing season are greatly appreciated!



Hello Alan and welcome to Mirai,

my take is that the type of fertilizer hinges considerably on your view on soil biology. Any chemical fertilizer will have the nutrients “readily” available for the plant (crf or not) vs. needs to be made available for the biological version. And here the stimulation and symbiotic relations of the microflora as well as biota in your pots come into play. I do not know the book, but general terms of “better” require proper context imo and there is many times not only one valid way. But when he states apparently (again, i did not read his book) - not better and maybe even not as effective - my question would be on which are the measurement terms for this statement and why can he not produce a clear verdict then. But why not test for yourself and come to your own conclusion based on your actual situation?
Oh, and you might guessed it, no CRF used here.



If the goal is to thicken the trunk or branches, chemical fertilizer is great. If you want to get refinement, and you don’t want long inter-nodes or explosive growth, organic is the way to go.


In a Bonsai pot environment you want all the beneficial bacteria etc you can get for long term health of the tree and soil. You won’t get that with the use of chemical fertiliser.


With organics, you are going to build up the beneficial organisms in your pot. These benefits include many health advantages.
Just a quick opinion.


Hhhmmmm… to each his own.
Welcome to Mirai Allen!
I have not seen Mr. Morton’s book. I DO understand the mindset.
Just my opinion…
What THEY (above) said…
Inorganic NPK fertilizer will keep your plants fed. Lazy use of onetime per year CRF inorganic fertilizer will keep them alive all year. Shure, it works. They will grow like crazy! However, they won’t sing…
It’s ALSO been said that plants don’t need any fertilizer. They will get what they need from the breakdown of the soil. That is true, if they are in the ground with available composted material. However, the practice of using sterile inorganic bonsai soil (akadama, pumice, lava) requires some nutrient applications.
Soft fertilizer, organic material, digested by fungus and bacteria will give the trees the micronutrients and slow released NPK they need to sing.
Benificial symbiotic microbiom grow and add their micronutrients and vitamins. Short internodes, green leaves or needles, vibrant flowers, insect resistance, healthy trees.
I don’t have to be sold on this. I’ve been raised and educated to see and utilize organic gardening practices on my bonsai. Biogold type organics and Dr Earth type inoculant products. Organic compost, fish emulsions and seaweed will do this, too.
Try going for a year without vitamin C, D, B12, or iron. Kill your gut flora and fauna with antibiotics and antifungals. Go for a week without fiber in your diet… Have you ever had to eat K rations or MREs for a month? You would survive, but you would NOT be a happy camper…
Ooohh, the humanity!
That being said, I do have and utilize CRF and inorganic fertilizers. They will grow trees if I’m not watching them closely. Especially potted pre-bonsai or in the ground trees. I do NOT rely on them as a ‘refined bonsai’ frontline, stand alone practice. Organic microbiom. My trees are crazy healthy this season. Very little insect, fungal or root problems. Their microbiom helps keep them happy.
Balance of water and oxygen…lots of sun.
Now I JUST need apply more style and refine techniques…
Yea Mirai!


thank you @Norisan for sharing the book reference --> in my amazon basket … :grinning:
And Welcome to the Mirai Community! :evergreen_tree:

There’s evidence that organic fertilizers help improve the immune response of trees against attacks by pathogens through their effect on the microbiota in the soil. At the same time there is empirical evidence of collections (such as that of Walter Pall) where exclusive use of synthetic fertilizers does not have ill effects on the trees. One thing to keep in mind is that organic fertilizers, because they depend of microbial activity in the soil, do not work with temperatures below around 15C (about 60F) whereas the tree is active from 7C (about 45F) so depending on where you live and the regimen of fertilization that you need to apply (mostly for trees in development) you’d loose considerable time if you were to use only organic. I and many people here in Quebec use synthetic early in the spring and later in the fall and organic in between. Last point I want to make is that with organic, because the nitrogen in it takes approximately 4 weeks to be metabolized by the microbes, you have a lot more control of when you stop fertilizing. With CRF, depending on how long they last - usually 4 or 6 months, you need to plan more carefully when to apply it if you know that later on you will want to withdraw it. I have videos in youtube where I discuss some of the issues around synthetic vs. organic and also energy management in pines according to the mirai methodology where I discuss when to withdraw fertilizers for example in the case of multi flush pines prior to decandling.

@Norisan i already read the book and totaly desagree that they are equal. of corse in molecular NPK (like the book said), they are equal, but the there are other components in the molecular NPK organic and chemical fertiliser that can cause huge damage to the soil and the plant, like salinity of the sintetic. is true, i use them both, sintetic subdoses in the developping trees and organic in trees that im building primary ramifications. i already killed 2 itoigawa junipers with osmocote using the recomended dose, so in itoigawa i use only organic since 2018, but in j. sinensis i use osmocote too with no problems. i never use sintetic in deciduous bonsai. i noticed that the more open are your soil and the more you water the plant, less damage you cause using sintetic, but you need to replace in short times intervals.