I came across an easy and relatively cheap method of making fertilizer cakes out of regular fertilizer. It appears that simply feeding the trees out of the bag risks making the soil hydrophobic. I'll be feeding my trees for the first time next month and wanted to learn more about the use of fertilizer cakes. Have folks found that regular quick release fertilizer (Miracle Gro or whatever) makes the soil hydrophobic over time? Does the use of cakes solve this problem? Does it pay to buy cakes or make your own (seems easy, albeit stinky, to make your own)? Do the cakes need to be placed in containers or can they go straight onto the soil (not sure if they will just disintegrate and cause the same problems)?
I ask the question under the assumption that, in addition to this feeding, the trees will receive a weekly dose of fish juice.
Uh, have never heard of miracle grow making soil water repellent...if it is, probably means your soil isn't all that great.
Cake fertilizers don't "solve" anything. However, THEY CAN cause soil to become clogged over time, since traditionally they 're made with organic stuff like blood and bone meal, etc. which dissolves and works its way into the soil. Over time, they can form a layer on top of the bonsai soil.
Miracle Grow and soluable ferts like it are usually called "chemical" ferts, while cakes are generally called "organic" ferts. Both are useful, but for different things. Chemical ferts are more readily available to the tree, while organics take months to break down into useful form (with the assistance of soil microbes).That means chemical ferts offer more immediate results than organics--making chemical better for faster growing development, while organics' slow steady stream is better for developed trees that don't need to push a lot of new/fast growth.
Making your own organic cakes can either be a stinky, maggot-infested mess, or a fun pass time. It's up to the maker to decide which...