How to Keep a Crepe Myrtle Blooming

Crepe myrtles are popular for Southern landscapes.

Crepe myrtles make an attractive choice for home landscapes. The pink and purple flowers of this popular tree display a graceful, lacy quality. While crepes are commonly considered trees, the truth is that biologically, crepe myrtles are shrubs. Training the multiple trunks of a crepe myrtle to grow tall in height and structure is what gives it a tree-like appearance. Whether you grow it as a tree or accent shrub, use techniques to attentively care for your crepe myrtle to keep it in bloom as long as possible.

Things You'll Need

• Pruning tools
• Bone meal
• Low nitrogen fertilizer

Instructions

1. Examine the location where the tree is planted. Make sure it is in a spot that receives the best sun exposure possible to promote continuous blooms. Select a location that gets no less than 6 to 8 hours of sunlight each day.

2. Check the soil conditions to by taking a soil test. Aim to achieve an ideal pH level of 6.5, or at least a range of 5.5 to 7.5. Amend the soil accordingly to increase or decrease the phosphorus and nitrogen levels. Use bone meal as a corrective fertilizer to add more phosphorus by spreading it around the circumference and watering it well into the soil surrounding the crepe myrtle tree, according to the label instructions.

3. Use a fertilizer that has a low nitrogen ratio, such as a 4-6-8, to promote blooms; too much nitrogen limits the duration and production of blossoms. Apply fertilizer twice a month in early spring after the plant comes out of its dormant period.

4. Wait until after the blooming season to prune the tree. Use a "less is more" approach to give the tree a more natural appearance. Avoid using a "topping" technique, where you level off the tree in a horizontal fashion. Expect a delay in blooming from six to eight weeks if you use this method.

5. Prune branches individually to maximize flower production and give each branch the opportunity to bloom at its fullest. Trim away dead branches to allow more light to filter through the leaves and flowers. Remove branches that cross over other branches and "deadhead" or remove seed and damaged branches. Cut twigs that are less than one-half inch in diameter or thinner than your finger to allow nutrients to feed mature and healthy branches.

6. Avoid using lawn fertilizers near the tree, as they often contain heavy amounts of nitrogen. Fertilize once each month during summer and end fertilization before the tree goes dormant in the fall.

7. Continue to review sunlight, pH level and light filtration through the tree's branches. Look for signs of powdery mildew on the leaves, as this can limit flower production and shorten the tree's blooming period. Eradicate mildew with a fungicide and apply per label instructions.

Tips & Warnings

• You can revive a non-productive crepe myrtle by cutting all of the trunks back completely to the ground. After that, you can manage the new shoots and even divide them.

References

• Auburn University: Common Crape Myrtle
• Crape Myrtle Trails: Most Asked Crape Myrtle Questions; Neil Sperry
• Houston Chronicle: How Do I Get Crape Myrtles to Bloom?; Kathy Huber, 2007.
• Heirloom Garden Experts: Crape Myrtle Care; Elmer Krehbiel, 2004
• Fast Growing Trees: Crape Myrtle Planting Instructions
• Gardening Know How: Fixing a Crepe Myrtle That Is Not Blooming

Resources

• Read this Article in Spanish
• Seminole County Florida Extension: Crape Myrtle