Protecting evergreens and other November gardening tips

Some woody perennials — technically called “subshrubs” — such as butterfly bush, lavender, thyme, and heather, can be damaged or killed if you prune in fall. Leave the stems as is, protect them with mulch over the winter, and prune in spring.

Mulch perennials, tender shrubs, and newly planted trees with bark, straw, or pine boughs after the ground has frozen to a depth of 1 to 2 inches. By the time the ground freezes, rodents have usually found a winter hiding place and will not burrow in the mulch and feast on your plants.

To prevent sunscald and frost cracking on young, thin-barked trees such as maples, wrap the trunks with tree wrap or paint the south- and southwest-facing sides of the trunk with white, outdoor latex paint. This will reflect the warming rays of the sun so the tree bark doesn’t heat up on winter days, only to be suddenly cooled when the sun sets and the temperature plummets.

Once the ground begins to freeze and you have consistent temperatures in the low 20s (F), it’s time to protect modern hybrid roses from winter’s wind and cold. Most old-fashioned or shrub roses shouldn’t need protectio. The simplest method is to mound bark mulch around the base of the rose, covering the graft union (the swollen part of the stem near the ground). The mound should be about one foot tall. Wait until spring to cut back the canes above the mound.

Make sure evergreens have a good deep watering before the ground freezes because they continue to transpire, albeit slowly, during the winter. Protect young evergreens from wind damage during winter by wrapping them in burlap or using wooden protectors. Water these plants whenever the temperatures warm up in winter and early spring if there’s no snow cover to provide moisture and the ground thaws.

If you have any clay or ceramic pots that you keep outside or in a cold location during the winter, empty them of soil, which will freeze and expand and, most likely, crack the pot. This even can happen to plastic pots too. Keep the soil to use to fill the bottoms of large planters next year. That way you won’t need as much fresh soil.

Other gardening tips for this month include leaving asparagus stalks to trap snow, cleaning and storing garden tools, stocking up on bird seed, and storing pesticides where they wont freeze. Visit the National Gardening Association’s web site ( for more information on gardening and regional reports

Dr. Leonard Perry is Extension Professor, Department of Plant and Soil Science at the University of Vermont. Visit his website at