The crape myrtle (Lagerstroemia indica) is a small flowering tree or a large bush that blooms in various shades of red, white, pink, or purple in the summer and fall. A crape myrtle is a low-maintenance plant that can reach heights of 30 feet, providing privacy as a hedge or screen planting. Fertilizing a crepe myrtle encourages new growth and blooming, but over fertilizing decreases blooming and can burn the plant, eventually leading to plant death.
Fertilize a new crape myrtle in early spring, beginning in March or early April. Add 1 teaspoon of a general-purpose fertilize once a month until August, spreading the fertilizer evenly over the soil around the plant. Keep the fertilizer localized to the planting hole to avoid getting the fertilizer too close to the base of the plant.
Fertilize mature crape myrtles in early spring when the plant begins to actively grow. Fertilize again in early summer to encourage blooming. Well-established crape myrtles that are large and several years old need only need the first round of fertilizer in spring, but you can fertilize again in summer if desired.
The amount of fertilizer depends on the type of concentration of the fertilizer product used. In general, a crape myrtle needs 1 pound of fertilizer for every inch of trunk, or 1/2 pound of fertilizer for every 100 square feet of canopy spread. Measure the diameter of each trunk that emerges from the ground in inches and add these measurements together to obtain the total trunk diameter. Measure from the center of the plant to one outside edge of canopy in feet to the other to obtain the radius of the canopy. Multiply the radius by itself and then multiply by 3.14 to determine the number of square feet of the canopy. You can round the numbers to simplify the calculations, but err on the low side to avoid adding too much fertilizer.
Fertilize when you expect rain the same day or the following day when possible. If you do not expect rain, water thoroughly after adding fertilizer. Soak the ground where you spread the fertilizer to allow the fertilizer to penetrate to the roots of the plant. Use an irrigation system or garden hose to water the crape myrtle after each fertilization.
- University of Georgia College of Agricultural & Environmental Sciences; Crape Myrle Culture; February 2009
- Crape Myrtle Trails of McKinney; Most-Asked Crape Myrtle Questions; Neil Sperry
- Fort Valley State University College of Agriculture, Home Economics and Allied Programs: Crape Myrtle-Fertilization
Fertilizer for Crape Myrtle Trees
Crape myrtle is appreciated for its strong, muscular trunks and its panicles of crepe-like flowers. An easy-care small tree, crape myrtle benefits...
How to Care for a Crepe Myrtle Tree
Crape myrtle (Lagerstroemia Indica), sometimes spelled crepe myrtle, is a graceful, flowering tree that provides year-round beauty in the form of attractive...
How to Prune Crape Myrtle
Crape myrtle (Lagerstroemia indica) blooms indefatigably throughout its perennial range in U.S. Department of Agriculture plant hardiness zones 7 through 9. The...
How to Take Care of a Crape Myrtle
Crape myrtles are beautiful trees that produce blooms in shades of pink, purple, white or red. Crape myrtles can add color to...
How to Keep a Crape Myrtle Blooming
Crape myrtle (Lagerstroemia indica) can bloom for two months or longer in the right conditions and with suitable care, but a shady...