Answer: Lagerstroemia fauriei is reliably hardy as far north as USDA Hardiness Zone 6. Your zip code places you in zone 6 so I think your new crepe myrtles have a fighting chance for survival. Since you've planted them close to a foundation they should benefit from the protection of the building. You can add more protection in the late fall when the plants are dormant. Just mulch around the bases of the plant to help protect the roots. Even if the tops are killed back by winter weather, new shoots should develop from the crown of the plant. Best wishes with your crepe myrtles!
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