Answer #1 ·
Brooks Wilson's Answer · Hi Colleen,
The Sioux Crape Myrtles can get as tall as 15-20'. To keep them at 6-8' will be an ongoing task of pruning. If you prune them to 5 or 6' height in early spring they will probably put on about 5-6' feet of new growth prior to bloom time. You will need to prune them 2-3 more times before bloom buds form to have a chance of keeping them below the 6-8' range.. If you prune them too late you may not get many blooms. I wouldn't prune them any later than June. Over time the trunks will get much larger, maqking it more difficult to prune. The Pink Velour Crape myrtle would be much easier to maintain as a shrub. It's mature height is 8-10'.
Hope this helps you out.
Brooks Wilson)