Answer: In your area, crape myrtle grows best in a full sun location in a warm microclimate with protection from winter winds. (Make sure you select a more cold tolerant cultivar that is considered reliably hardy in zone 6.) It will do fine in average or better soil that is evenly moist yet well drained. Mulch year round with a flat layer of mulch over the root area, but do not allow it to touch the stems. In winter, increase the mulch to about six inches deep, the rest of the year two to three inches is enough. Each spring apply a top dressing of good quality compost along wiht a slow release or general purpose fertilizer with an analysis of 10-10-10 or similar proportions. Water as needed to keep the soil moist but not sopping wet or saturated. Although some gardeners prune back their crepe myrtles each year in late winter, this is not at all necessary. Each spring you do need to remove any winter killed branches (be very patient before you decide something is dead, these plants are slow and leaf out very late in the season) and then can prune a bit if needed to restore a roughly symmetrical look. If you want your plant to be more of a tree form, limit it to just a few trunks. If you need to prune to control size, do your pruning in late winter or early spring. This plant blooms on new growth of the season, so pruning in summer will reduce or stop it from flowering. Fall pruning will encourage late season growth that may not have time to harden before winter cold sets in. I hope this helps!
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