What plant hardiness zone is Cromwell
Cromwell is located at Middlesex County, Connecticut (CT), USA.
Plant hardiness zone (winter frost zone or gardening zone) for Cromwell is 6b by the USDA scale.
Coldest zone's winter temperature is −5 … 0 °F.
Plants of 6b USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 6b USDA.
Cromwell, Connecticut @ wikipedia.