by Helen Weiser

Two factors affect the ability of grafted roses to survive winter: good drainage and protection from bitter, penetrating cold and drying winds. Without sufficient drainage, water accumulates in the soil, freezes in the cold weather, and causes ice damage to the roots. Without protection from cold temperatures, the top growth of the plant is in jeopardy and often some or all of the canes die back. Roots can usually recover from severe cane loss, but if the bud union itself is killed, the hybrid scion that produces the lovely flowers, is dead. The hardy understock may send up a few flowers but they won’t be very appealing. Ungrafted roses are not a worry with regard to winter. Most, including the old roses and climbers, are very hardy and can survive without protection. How do you know if your rosebush is grafted? Look underneath the foliage, at the stem that emerges from the ground. If you see a hard “knob,” that’s the graft union where two types of roses were joined to create a hybrid. Protecting the plant’s top growth is a job done every fall, after the first hard frost. This blast of subfreezing weather will help to harden the wood, better preparing the plants for winter. It’s not enough to harm the bud union, which can survive unprotected to around 10 degrees F. A good mulch is an organic material that has not been treated with weed killer, has an open texture that blocks sunshine but allows air and water to reach the soil, and that has substance enough to retain this texture fairly well. (They all mat down some during a season of ice and snow.) Salt marsh hay is a good choice because the week seeds it carries are unable to sprout outside the briny environment of the marsh. Don’t put mulch on too soon – while the ground is still soft – as rodents are apt to nest in the mulch and burrow down to feed on the plant roots. Most mulch should completely blanket the surface of the soil. With a little effort, you can protect your beautiful rosebushes so they can astound you with their beauty for many years to come. Plant of the Month: A beautiful native shrub that shines in fall is American Cranberry Viburnum. It is a gorgeous deciduous shrub, especially attractive in fall, with maple-shaped leaves that turn deep red, and its red berries are a great food source for birds in winter. It is a wonderful space filler as it grows 8-10 feet tall. It’s certainly a shrub to contemplate as you settle in for the winter and plan next spring’s garden.