Bonsai are formed plants and trees that are trained and maintained into a specific size and shape. The techniques take years to learn properly, and many bonsai specimens are literally invaluable. Taking care of a bonsai is a labour of love and requires vigilance and consistency. Bonsai are grown in small shallow pots, often smaller than you would imagine could support such a plant. These tiny pots do not allow for much soil and nutrition storage. In fact, bonsai require frequent leaching to remove excess salts and detrimental compounds, and this removes nutrients. Bonsai therefore require frequently feeding, and knowledge of their nutrient requirements can assist you in making an organic bonsai fertiliser.
Cut a square of cheesecloth big enough to hold 363gr. of compost. Fill the 1-gallon bucket with rain or distilled water. Fill the cheesecloth with the compost and tie it shut with twine. Suspend it in the bucket. The compost tea will need to steep for three weeks.
Strain the tea into the 5-gallon bucket and dilute it with 4 parts water. Use the compost tea instead of water every other time the bonsai requires water to give it balanced nutrition. The compost provides the basic macronutrients of nitrogen, phosphorus and potassium in an organic solution.
Mix rainwater with 1 cup fish emulsion in a spray bottle until it is the colour of weak tea. Spray generously once a month to provide extra nitrogen for green growth and phosphorus for healthy roots.
Mix the 4 cups bone meal, 4 cups cottonseed meal and 1 cup baking flour in the 1-gallon bucket. Add 3 cups fish emulsion and 2 cups liquid seaweed. Don your rubber gloves and mix the ingredients with your hands.
Push the mixture into the PVC pipe. Press it in firmly with the dowel while keeping the opposite end closed. This will pack the mixture. Once packed, push hard with the dowel to force the mixture out onto a large screen.
Cut the mixture into 1-inch cakes and leave them on the screen for several days to dry. Store them in a closed container for future use. Recommended dosage is 3 to 6 cakes dotted across the top of the bonsai. The amount varies according to the size of the tree; larger ones need more cakes. When you water, the fertiliser will leach into the soil.
Remove old cakes in four weeks and replace with new ones. The homemade fertiliser is providing slow-release, complete nutrition to your bonsai.