Flowering dogwoods are native to the eastern half of the United States, but they can be found as introduced species in other parts of the country. Flowering dogwoods grow to between 20 and 35 feet tall with a spread of 20 to 25 feet. Dogwoods prefer a deep sandy or loamy soil that drains well. This tree grows best in partial sun; trees growing in full sun tend to grow more slowly.
Dogwoods do better with being fertilized by decomposing mulch. If your soil needs fertilization, organic fertilizers such as compost often work well. However, if you need chemical fertilizers, a 12-4-8 fertilizer is good for dogwoods at most growth stages.
Do not fertilize your dogwood the first year. Until your dogwood reaches six feet tall, fertilize in February and June with 1/4 cup 12-4-8 fertilizer. Scatter the fertilizer around the base of the tree, but do not allow it to come into contact with the trunk.
For midsize trees, use 1 cup 12-4-8 fertilizer per inch of trunk diameter scattered evenly in a 100-square-foot area under the tree. Alternately, you can apply the equivalent of 3 ozs. nitrogen per 100 square feet of area under the tree. The amount of fertilizer depends on the type you are using. If using organic fertilizers, this may require more because most organic fertilizers contain lower concentrations of nutrients than chemical fertilizers.
Mature trees do not require as much fertilizer as younger trees. If your dogwood is growing in your lawn and you are fertilizing your lawn, this should be more than adequate for your dogwood. However, if you are not fertilizing your lawn or your dogwood is not growing in a lawn, reduce the amount of fertilizer. The amount of reduction will depend on the existing nutrients in your soil.
Over-fertilization is a frequent problem for young dogwoods. In some cases, the tree may die from over-fertilization. Fertilize for moderate growth. If you fertilize for vigorous growth, the tree may grow but at the expense of flowers.