How to overwinter rosemary

Q. How can I keep my rosemary alive during our harsh winters?

Mary from Canfield

A. I love rosemary. With its distinctive pine smell, its lovely blue flowers and strong flavor, it is an herb that makes its presence known. When I see 4-foot shrubs of rosemary in southern states, I am green with envy. I want mine to survive like these.

Rosemary has its origins in the Mediterranean, with hot sun; sandy, well-drained soil; and mild temperatures – definitely not here in Ohio. We consider it a tender annual, but if you also love rosemary, it is fun to experiment with keeping it year-round.

Most garden advice recommends potting rosemary plants from the garden in the late fall and bringing them indoors for winter. Your chances for success may be increased if you start with rosemary grown in pots on decks or patios, rather than digging up garden plants. Remember that it needs a cool resting period and our comfortable homes are too warm, so search for the coolest spot in your home. It also needs just the right amount of water. Too much and it can die of root rot; too little and it is a dried-out stick. Create a moist atmosphere by placing the plant on a saucer filled with pebbles and water. Circulating air helps prevent fungal disease such as powdery mildew.

After many failed attempts to over-winter rosemary indoors, I have experimented with leaving it outside over the winter, and I am happy to report some success. I have planted rosemary on the east side of my house, sheltered from the harsh west wind. By placing the plants close to the brick walls, they get a natural warmth from the winter sun. In late fall I make sure they have been watered well so they start the dormant period with moisture, and I add a natural mulch of dried leaves for protection. The cultivar “Arp” is one of the more cold-tolerant varieties, and is generally available in our area. Several winters I have been rewarded in the spring with a large rosemary plant, almost 2 feet tall, covered in blue flowers.

And if you are successful over-wintering rosemary? Then experiment with all the ways to add rosemary to your life. In cooking, add rosemary (sparingly) to meats, poultry and fish. It is delicious added to oils and vinegars for salad dressing. Sprinkle a few leaves on potatoes when roasting. It is great for aromatherapy. Add a few sprigs to warm bath water to create your personal spa, or add a bundle to a fireplace to scent the room. Best of all, just clip a sprig, hold it in your warm hands, breath in that wonderful aroma – and let your stress evaporate.

For more information, visit http://go.osu.edu/rosemary.

Today’s answer is provided by LuAnn Haddad, OSU Extension master gardener volunteer in Mahoning and Columbiana counties. Winter hours for the Plant and Pest Diagnostic Clinic vary. Submit questions to the clinic at 330-533-5538 or drop samples off to the OSU Extension Office in Canfield.