Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Pruning
Acoma is a unique, semi-dwarf weeping variety of crape myrtle. It can be left to grow naturally as a large shrub that will form a mound of branches that weep to the ground, or it can be limbed up to form a very attractive small tree with single or multiple trunks. If you want the tree form, it will be necessary to remove lower branches and suckers that emerge from the base of the trunk(s). Whether or not you prune the top (canopy) is up to you, but with this variety I'd suggest leaving the canopy alone...maybe just doing some light "tip pruning" of the outermost branches to remove seed pods. The best time to prune would be in very late winter or early spring, just before new growth begins to emerge. When pruning branches less that an inch or so in diameter, I use a quality pair of sharp bypass hand pruners.

Rather than go into more details of pruning a crape myrtle for tree form 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

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Feeding
Though some people never fertilize their crape myrtles, I would suggest a once-a-year feeding in the spring, just after new growth has emerged. be careful about the fertilizer you use on crape myrtles. You don't want to use a fast-acting fertilizer or one that has too much Nitrogen (the first number in fertilizer) that will cause foliage to grow too fast. Instead, use a well-balanced, slow-release "shrub and tree" food with a range of micro and macro nutrients or maybe an organic plant food. I always go the organic plant food route because the nutrients are more readily absorbed by the plants roots.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Problems
Crape myrtles don't have any serious problems with pests or disease. That being said, they aren't entirely immune. Unlike other older varieties of crape myrtle, Acoma, and other crape myrtles with Indian names (the Faueri Hybrids) have very little problem at all with powdery mildew or any other diseases. Regarding problems with insects, all crape myrtles attract the Japanese beetle in early summer and, then, maybe honeydew aphids in late summer or early fall. But neither of these insects do much harm or damage to the plant. To control Japanese beetles there's nothing better than liquid Sevin (Carbaryl). It's cheap, low in toxicity as far as chemicals go, and highly effective. To control the honeydew aphids, which leave a sticky residue on leaves that eventually turns black and is often thought by many to be a fungus or mold, can be controlled with products containing Neem oil or Malathion. That being said, I rarely if ever treat crape myrtles for insects, as even the Japanese beetle doesn't do enough noticeable damage to make spraying worthwhile.