Fertilizer provides extra nutrients that trees need to remain healthy and grow to their full potential. A healthy tree is less likely to succumb to disease or attract insects that may harm it. It is not necessary to spend a fortune purchasing chemical fertilizers for your tree; you can make a homemade tree fertilizer with a few simple ingredients.
Mark your calendar for the end of April or the beginning of May. This is the best time to fertilize trees because they have their biggest growth spurt in the spring. The extra nutrients will be highly beneficial during this time.
Measure the drip line diameter of your tree---the distance from the trunk of the tree to the edge of the circle where water drips down from its leaves, times two. Round this number to the nearest foot, then multiply it by four, and that is how many pounds of fertilizer you'll need to make for your tree. For example, if you measured a drip line diameter of 2 feet, you would need 8 pounds of fertilizer (2 x 4).
Place your blood meal, steamed bone meal, wood ashes, and dolomitic limestone in the large bucket. Mix the ingredients together.
Put on a pair of gloves and sprinkle the fertilizer around the base of the tree out to the tree's drip line.
Rake the fertilizer into the soil. Water the area so that the fertilizer is taken even deeper into the soil.