Question
I am wondering what type of fertilizer to us on my crape myrtle . Should it be an acid or something else. My crape myrtle is very slow growing. It will have beautiful blossoms when it does bloom.Please advise. Thank you, Karen

Answer
Crepe Myrtle ('Lagerstoemia indica' to botanists) blooms in July here up North.  The Soil pH must be on the acid side.  Its cone-shaped clusters can get huge -- provided you don't prune this plant wrong.  That's the secret to growing Crape Myrtle.  Not fertilizing properly, but pruning properly.  Never prune a Crepe Myrtle after growth starts in the Spring.  Doing that risks clipping off future blooming growth.

Although they need Phosphorous to bloom, young Crepes really need the rich Soil even more for blooms to reach their potential.  Homeowners who use high-Nitrogen tree fertilizer spikes to feed this plant will find foliage without flowers.

Instead, top-dress your Crepe Myrtle with Bone Meal, which is high in natural Phosphorous, and Mushroom Compost.  They won't burn the plant and they'll conditino the soil it is growing in.  Phosphorous also builds strong, healthy roots.  Soil testing will pinpoint potential shortages and keep you from wasting money on things you do not need to get this plant growing to its full potential.

Another basic need of this plant: LOTS of Sun.  

Besides a ton of sun, these trees need close attention to watering, especially in the South where they are prone to dry out, and especially when they are small and root systems are still developing.

When you do get blooms, be sure to cut them off once they fade.  This is a good practice with any flowering plant or shrub, but one people pay less attention to with outdoor plantings.  It keeps the plant from pouring energy into seed production.  Any saved energy will be used for the next flush of flowers.

If your Crepe is still small, this is the time to train it for future shaping.  Do you want it to shape it into a curbside or yard Tree eventually?  Remove suckers from the base and train to a single trunk.

On a more shrubby plant, keep the interior thinned to encourage air circulation.

These are hardy all the way up here, as north as Zone 6.  We don't have enough of them.