Fall Zone 2, 3, 4: Early September. Zone 5: Early to Mid September Zone 6: Mid September Zone 7: Mid to Late September Zone 8, 9, 10: Late September to Early October Spring Zone 3, 4: Early to Mid May Zone 5: Late April to Early May Zone 6: Mid to Late April Zone 7: Early to Mid April Zone 8: Late March to Early April Zone 9, 10: Late March