Broadcasting gorgeous pink, white, or red blossoms across their limbs, the dogwood tree (Cornus florida) is a complementary addition underneath a large tree canopy; dogwoods do not enjoy full sunlight. Preferring fertile soil, dogwood trees commonly need periodic fertilizing throughout their lifetime for the best growth and blooming potential. Two specific types of fertilizer work well for this plant, which dwells in U.S. Department of Agriculture hardiness zones 5 through 9.
Dogwood trees grow well with a 12-4-8 fertilizer ratio. The abundance of nitrogen, denoted by the first number, reflects this element's importance to the tree. Nitrogen provides the basic structure for chlorophyll, the main pigment necessary for photosynthesis within the leaves. Although important as contributing macronutrients, both phosphorus and potassium are in lower ratio amounts compared to the nitrogen; phosphorus helps with energy needs through adenosine triphosphate, and potassium provides cell division properties for a growing dogwood.
For gardeners with nitrogen-deficient soil, a 16-4-8 fertilizer helps keep the dogwood healthy. Low levels of nitrogen become apparent on the tree; stunted growth and light green leaves are a sure sign of low nitrogen. Using the fertilizer with the same phosphorus and potassium levels, along with higher nitrogen amounts, provides extra nutrients to the tree for optimum photosynthesis.
Incorrect Fertilizer Consequences
Choosing a fertilizer that is not deemed compatible with a dogwood tree can cause significant damage or death to the plant. Incorrect fertilizer ratios subject the tree's roots to an imbalanced soil composition; the roots can rot from high salt quantities or pH level swings, depending on the nutrient ratios in the fertilizer. You can easily check your soil's nutrient needs by using a soil test kit. Commonly sold in gardening or home improvement stores, these kits give you an accurate account of the soil's nutrient needs so that the correct fertilizer can be pinpointed.
Considering Fertilizer Needs
If your soil test kit shows a healthy mixture of all 16 macro- and micronutrients, you should not need to fertilizer around the tree. Specific dogwood trees, such as those younger than 1 year, should not have fertilizer applied to their soil. Their roots are beginning to establish themselves and are highly sensitive. Dogwoods near lawns that are constantly fertilized should not need fertilizer either; the spreading root system can use the lawn's fertilizer as an acceptable source for healthy growth.
Your Planting Articles
- Pennsylvania State University Extension: Growing the Flowering Dogwood Home and Garden
- University of Illinois Extension: Selecting Trees for Your Home: Flowering Dogwood
- University of Georgia: Growing Dogwood
- North Carolina State University: Flowering Dogwood
- University of Florida IFAS Extension: Fertilizing Your Home Lawn
- North Carolina State University: Essential Plant Nutrients
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