Plants have a difficult time surviving in the winter. Plants do not generate any heat of their own and winters can leave plants vulnerable to diseases such as black spot, a disease that commonly afflicts roses during wet winters. Rose bushes have a particularly difficult time surviving winter months, but taking special precautions can increase the chances that the rose bush survives the winter.
Rose bushes can sometimes be transported to warmer locations before the winter comes, but this should be done no later than September, since the roots of the rose bush need time to become accustomed to the new soil. Rose bush owners can risk transporting their bushes in the middle of winter when the roses are dormant, though it is possible that this will kill the rose bush. Add vitamin supplements to the rose bush’s water before transporting in order to maximize its survival chances.
Adding phosphorus and pot ash, beginning in September, can cause the rose bush roots to harden, which will increase the chances that it will survive the winter. Add the phosphorus and pot ash mixture twice a month until the first freeze. Read the instructions on the commercial mixture on how much to apply, since different products have different concentrations.
During extremely long and cold winters, rose bushes can be protected by wrapping them in newspapers, paper bags and plastic bags in order to insulate them. Adding mulch can also help by increasing the chances that the rose bushes go dormant. Add the mulch after the first freeze to prevent rodents from tunneling through.
Usually, rose bushes do not require pruning in the fall. The extra branches on the rose bush will act as a buffer between the inner parts of the rose bush and the exteriors when part of the rose bush dies as a result of the freeze. However, Andy Crossland, Adams County Master Gardener, advises to prune those rose bushes that are exposed to areas with high winds. Remove the leaves from the rose bush because the leaves can become infected with bacteria and cause diseases such as black spot, powdery mildew and rust. Not only will these bacteria kill the rose bush, but they might spread to other flowers in the garden.
No matter what is done, rose bushes will sometimes not be able to survive a cold winter. If the rose bush is killed in the winter, dig up the rose bush and burn it, since rose bushes do not make good compost for the soil and the dead branches often attract bacteria, which will contaminate the soil and can make future plants sick, according to Ellen Palmer, Grays Harbor Master Gardener.