Garden: Boxwoods lovely, but need winterizing

Nancy Szerlag
Special to The Detroit News

When it comes to choosing evergreens for landscaping, boxwoods are among the most popular. They’re particularly loved for use in formal plantings, where they can be pruned into hedges, balls, boxes, structures and creatures.

Recommended cultivars, hardy to Southeastern Michigan, include Green Velvet, Green Mountain, Buxus microphylla koreana and Winter Gem.

Unfortunately, the brutal cold and winds of last winter were particularly hard on boxwoods left to weather the storms on their own.

Word on the street is this winter may be colder then the last. I don’t always listen to street talk, but if I had lots of boxwoods in my landscape, I’d probably do some winterizing. Screens of burlap in front of the shrubs will help deflect drying winds. Martha Stewart encloses hundreds of boxwoods in burlap teepees. For step-by-step instructions, go to

Whether you wrap or not, spraying boxwoods with an anti-transpirant, also called an anti-desiccant — a wax-like substance that helps seal moisture in the leaves, may also help protect the plants from winter burn.

In her blog entry on “winterizing boxwoods,” ( landscape maven Deborah Silver, owner of Detroit Garden Works in Sylvan Lake, recommends the anti-desiccant Vapor Gard, a commercial product available on The downside to this product is it’s only sold as a concentrate in gallon containers that cost more than $100. And it’s best applied with a backpack or commercial sprayer.

Darrell Youngquest, nursery buyer at English Gardens, sprays the many boxwoods in his landscape with the anti-desiccant Wilt Stop Plant Protector from Bonide, which is available in concentrate or ready-to-use formulas. Youngquest says timing and technique are both important when using anti-desiccants. He makes sure to coat the top and underside of the leaves to the point of runoff. The temperatures must be above freezing when the product is sprayed so the liquid can dry before it freezes. The label also says sun is needed to set the product. Bonide recommends spraying in late autumn, and Youngquest targets Thanksgiving as the optimal time.

Youngquest says late season pruning can also lead to winter damage on boxwoods. Pruning stimulates new growth, and if done too late in the season, that tender new growth will not have time to harden off before the plants go dormant. He likes to get the job done in his yard by the 4th of July.

Wilt Stop can also help protect plants from salt damage, so consider using it on plants that line driveways and sidewalks.

Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. Email her at Szerlag You can also read her previous columns at