Crepe myrtle (Lagerstroemia indica) can and does grow in Westchester County but with some caveats. Some cultivars are advertised as winter hardy in the northeast, but our experience is that while the roots will survive in the climate zones of Westchester County, the above ground plant may die back.

If you are living in USDA zone 7a (areas along the Hudson River, the LI Sound or close to NYC), then the plant should be fine over the winter with some protection needed if it gets particularly cold. If you are in zone 6, the plant has a greater chance of dying back over a harsh winter. The plant can still be grown like a buddleja bush and cut back to the ground for new growth in the spring if the plant dies back.

You should plant the crepe myrtle in a protected spot (near a wall or with trees and structures around that will break some of the wind and shelter it) for best results. Get it planted as soon as possible after Mothers' Day so that the roots are well established by winter time. It needs full sun (6+ hours per day), with full, hot sun producing the most flowers. Place it in soil that drains well and mulch the roots heavily for extra protection. Water 3 times per week at a minimum during the first growing year.

'Violet Filli' is a cultivar in the Fleming Filligree™ series, which are hardy to zone 4 or 5 (below ground) and grows only 1 to 1.5 ft. tall and wide. It has strong purple  flowers and an extended period of profuse bloom. You should consult with a reputable, local nursery for availability or recommendations on alternatives.

Courtesy of NYBG Plant Information Service