Can I overwinter my fennel plants in an unheated garage?
Question:
I have three swallowtail fennel plants in pots. They are about 2 1/2 feet high. Can I put them in an unheated garage? Do I cut them back? Do I water them?
Answer:
While there are some varieties of fennel that are hardier than others and fennel can be grown as a perennial herb in warmer climes, the species generally prefers higher temperatures than what we have in store for us. It also tends to be a rather short-lived perennial, anyway. I fear that trying to overwinter it in an unheated garage in Maine would kill them off. If you are committed to trying, you should cut it back, mulch the potting soil thickly, insulate the pots by wrapping them and keeping a blanket of floating row cover on top, and place the pots as close to the entrance to your condo as possible. Then roll the dice.
A better and far more certain approach would be to harvest the fennel now, preserve it (assuming you use the plants for cooking, as opposed to aesthetics), and pick up some new seedlings in the spring.