Rosebushes need TLC in the fall and winter to really flourish in the spring and summer. It’s particularly urgent if this is your rosebushes’ first winter because young plants are less resilient—and replacing one can cost $25 or more. But even established rosebushes can be vulnerable, especially popular “hybrid tea” varieties. These often are grafted, so while there’s a winter-hardy root system, the top growth is tender. Here’s how to protect them…
• Slow down this fall. As days grow shorter and the air and soil begin to cool, water rosebushes less often and stop fertilizing. You don’t want to encourage fresh stems, leaves or buds, as new growth is easily damaged by cold. Stop deadheading (removing spent flowers), too. Instead, let flowers drop their petals and form rose “hips.” When you let the hips form, the plant gets the message that it’s time to slow down for the year.
• Prune in early winter. Before deep freezing sets in, clip off dead, weak or diseased shoots and dispose of them (do not leave them on the ground under the bush, where they can harbor pests or diseases that may resurge next spring). Cut back the healthy stems by about a third, too. (No need to worry about such fine points as removing buds that are too low on the branch…that kind of precise pruning and shaping is for spring.) Tip: If your winters tend to have cycles of freezing and thawing, which can cause damaging drying, spray your rosebushes with an antidesiccant such as Wilt-Pruf to seal in moisture. Get this inexpensive, organic product wherever garden supplies are sold and follow label directions.
• Build up the base. Before the ground freezes hard, use a shovel to pile up soil around the base of your rosebushes. Get the soil from elsewhere in your yard (digging close to the plant may expose roots) or from a fresh bag of soil. Be generous—six to eight inches if winters tend to be moderate…twice as much for very cold areas. The soil conducts heat from the ground and protects the spot where the top growth was grafted onto the rootstock (visible as a slight bulge on the main stem). Then add more protection by adding mulch on top. You don’t have to use fancy store-bought mulch—chopped fall leaves, pine needles or bark chips will do. Prop evergreen or other branches over the mounds to hold everything in place. Tip: Wind twine around the stems if you are worried about winter winds whipping them around and possibly snapping them.
• Go slow in spring. Don’t be in a hurry to remove all this protection in the spring or new growth will be damaged. Wait until there are no more frosts and you are sure the ground has thawed.