I've had a lemon tree growing by my driveway in Southern Maryland for at least five years. It's 20 feet tall and bore fruit for the first time this summer. Obviously it can withstand snow, freezing temperatures and drought. The lemons are mostly large and delicious. Isn't this unusual in Maryland?
Lemon trees are classified as tropical. They normally need to be placed indoors as protection against Maryland's winters. However, a couple of cultivars are hardy down to 17 degrees, namely, Meyer and Lisbon.
We have had several mild winters in a row. Be prepared to protect your lemon tree should a severe winter arrive.