Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Pruning
Crape myrtles do not have to be pruned. However, if you want to form a nice tree with a full canopy and heavier flowering, pruning is required. Rather than go into all the details of pruning a crape myrtle tree here I'll just post a link to an article I wrote that provides detailed instructions for a method I've used successfully for 25 years: http://www.gardenality.com/Articles/344/How-To-Info/Pruning/How-To-Prune-A-Crape-Myrtle/default.html

Lee Veal · Gardenality Seed · Zone 8A · 10° to 15° F · Comment About Problems
We have an extremely large crepe myrtle, easily 20' that looks like it has not been trimmed in many years. My husband just trimmed it back to about 6' and I am concerned it is just hacked. I suppose that all we can do now is wait to see if it grows?

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Pruning
Hi Lee,

Since your tree was cut back from 20 feet tall to 6 feet tall, I would agree with you in that it was "hacked" to far back...much too far. When a crape myrtle is cut this far back it will send out new growth and continue to grow but never look like it might have when and if it was properly pruned. That being said, and outside of just removing the remaining stumps, there are things you can do now that might give you somewhat of an attractive tree again.

Here's a link to an article that provides instructions for corrective pruning when a crape myrtle has been hacked back to stumps:

http://www.gardenality.com/Articles/345/How-To-Info/Pruning/How-To-Prune-A-Crape-Myrtle/Instructions-for-Pruning-a-Crape-Myrtle.html

Hope this info is helpful,
Brent

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Planting
Crape Myrtle grows in a wide range of soil types but prefers a well-drained site. For best performance, plant in full to mostly sun. Some shade will be tolerated, but flowering will likely be reduced. As one of the taller growing crape myrtle Arapaho is most attractive and useful when grown as a mid-size tree. It can be planted as a single specimen or in groupings anywhere in the sunny landscape and is also useful on the corners to frame taller homes.

To plant a crape myrtle, dig a hole no deeper than the root ball and two to three times the width of the root ball and fill it with water. If the hole drains within a few hours, you have good drainage. If the water is still standing 12 hours later, improve the drainage in your bed, perhaps by establishing a raised bed or mound. Turn and break up the soil removed from the planting hole. If the native soil is dense, compacted or heavy clay mix in a good organic compost or soil amendment at a 30/70 ratio with the soil removed from the hole. Remove your plant from its container and carefully but firmly loosen the roots around the exterior of the root ball. Set the plant into the hole you've prepared, making sure the top of the root ball is slightly above the soil level to allow for settling. Pull your backfill soil mixture around the root ball in the hole, tamping as you go to remove air pockets. Then water thoroughly and cover with a one to two-inch layer of mulch.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Feeding
Crape Myrtle aren't heavy feeders. I usually fertilize them one time a year with a slow-release, well-balanced shrub & tree type fertilizer after new growth has emerged in spring. Quick release fertilizers aren't good for crape myrtle because they promote long and weaker stems that might droop too much from the weight of the large flower clusters.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Problems
Crape Myrtle are very tough plants that have few serious insect, pest or disease problems. Arapaho is a Fauriei Hybrid that has demonstrated excellent resistance to powdery mildew, which is a quite common problem on older varieties. Japanese beetles may visit crape myrtle during summer but do very little if any damage to the tree. Honeydew aphids might visit crape myrtles in late summer or early fall. These small green critters hand out on the back side of leaves during the day and venture to the top side of leaves at night, where they leave a sticky residue that turns black. I usually don't spray for these aphids unless it's a serious infestation because they cause little if any long term damage.