by John Callaway

All living things need nourishment to grow. Animals need food, water, and air to live. Plants need air, water, and sunlight to make their own food. Plants and animals must also have a healthy dose of other materials to remain healthy. This is why we're constantly reminded to maintain a complete, healthy diet. Plants also need a healthy diet.

For bonsai trees to live in the environment that we've placed them in, we must provide a certain amount of nutrition. The soils in which we grow our trees contain little or no organic matter to provide this type of feeding, so we routinely add these things to our soil. The amount of organic matter and the frequency of watering may help you determine how best to feed your trees.

There are many ways that we can provide nourishment to our trees. Fertilizer is a must to keep bonsai healthy. Whether you choose to use liquid or solid, organic or inorganic is a personal choice. However, there are some major advantages to using organic fertilizers.

Organic fertilizer cakes, such as the ones described below, are extremely easy to apply. Take a certain amount of cakes and place on top of the soil, the larger the pot, the more cakes. Then simply water and forget. These cakes will need to be removed and/or added to throughout the growing period. The ease of this process is greatly appreciated when trying to control the growth of certain species by adding and removing cakes as needed. From time to time I may apply a dose of liquid iron and/or some MirAcid for those trees that appreciate these amendments.

With each watering, small amounts of nutrients are passed through the soil and made available to the roots. The main advantage of this type of feeding is that it is a constant low dose. With fast acting, highly rated NPK liquids, you risk shocking the tree into producing long, leggy growth.

I was purchasing my fertilizer cakes from a dealer. As the amount of trees that I have continues to grow, I decided to try my hand and making some. Here is the latest recipe.

Ingredients:

• 4 cups bone meal (4-12-0)
• 4 cups cottonseed meal (7-2-2)
• 3 cups liquid fish emulsion (5-1-1)
• 1 cup baking flour (for firmness)
• enough water to make into a slurry

1. Mix ingredients in a 5 gallon bucket
2. Allow to ferment for 60 days
3. Form into small balls (I chose small paper containers)
4. Let dry and store, or apply immediately to your trees

Some people add a small amount of Sevin insecticide, but there is a potential of poisoning curious pets.

One caveat, this stuff stinks. When removing the lid after fermentation, be sure to hold your breath. Be warned, as bad as the ingredients smell going into the mix, the odor will easily triple its foulness in the next 60 days. Be sure to conduct a little research and start with the least offensive smelling ingredients that you can find. The fish emulsion is the biggest culprit, so I'll try to find a brand with a more pleasant smell for the next batch.

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Update: Over the last few years the fertilizer recipe has been tweaked and new updates have been made.  You can read about the update to the bonsai fertilizer cake recipe by following this link: http://www.matsubonsai.com/blog/post/2008/05/Bonsai-Fertilizer-Cakes.aspx