Question
I live in SW Virginia. One of my five crepe myrtles did not bloom at all this year. The others did well. What can I do to make it bloom? It appears healthy in all other ways, no insects, mold, and the leaves are dark green. I did not prune it. Last year it was new and it did bloom well. Is there a product I can add to the soil that will make it bloom? thanks for your help. Also, if I prune new blooms as they die, will it cause the tree to bloom again during the same season? thanks again for your help.  

Answer
Crape myrtle flowers on new growth of the season, so you can prune plants any time during the late winter or early spring before growth begins without loss of flower buds. Avoid pruning in early fall before the first frost, because pruning forces new growth and keeps the plant from going dormant. Severe freezes can kill the plant if it is not fully dormant.


Pruning, however, is not essential for flowering. Some of the most spectacular floral displays can be seen on old, unpruned crape myrtles along roadsides. Flower clusters are usually smaller on unpruned crape myrtles, but the number of flower clusters is greater. Therefore, the overall floral impact of the plant is not reduced.

On some cultivars, pruning to remove spent flower blossoms after they fade will stimulate new growth and another blossom flush in late summer. A second bloom is sometimes difficult to force on cultivars that bloom after mid-July.

I would also recommend that the trees be fertilized. A complete general-purpose garden fertilizer -- such as 8-8-8, 10-10-10, 12-4-8 or 16-4-8 -- is ideal for crape myrtle. To newly planted small plants (1-gallon size), apply 1 teaspoon of fertilizer monthly from March to August along the perimeter of the planting hole. Larger, established plants will benefit from one broadcast application of fertilizer in spring. Apply 8-8-8 or 10-10-10 at a rate of 1 lb. per 100 sq. ft. or 12-4-8 or 16-4-8 at a rate of ?lb. per 100 sq. ft. Avoid over-fertilization because it causes excess growth and reduced flowering. The best time to fertilize is just before a rain. Otherwise, water in the fertilizer after application with irrigation. It is not necessary to remove mulch when fertilizing.