Roses can be somewhat delicate, and special care should be taken to ensure their survival over the cold winter months. If you live in a very moderate climate with mild winters, you may not have to take any special steps. But in cooler climates, your roses should be protected.
In the fall, you should start gradually watering less and less. This happens over a few weeks, and water is restricted a bit more each week to help toughen the stems of the roses. This helps keep the stems protected throughout the winter.
When rose hips begin to form, it signals that the plant’s growth cycle is finished for the season, and it begins to go dormant for the winter. You shouldn’t prune or pinch buds at this time, because this can encourage new growth at a time when the plant should be shutting down.
Don’t remove dead flowers at this time, because they should be allowed to form rose hips. Rose hips are the fruit that is formed from dead roses. They are a great source of food for birds in the winter, and they also look quite attractive in a winter landscape.
In zones 7 and cooler, most roses will need to be protected during the winter. They must be sheltered from both the cold and the damaging winds. Snow can actually protect delicate plants, because the snow actually provides a blanket of protection that keeps the soil from becoming too cold.
This helps keep the roots protected from frostbite, yet it also keeps them from causing the roses to go into a premature growth cycle because the roots get too warm. You can cover the bottom part of your roses with about eight or ten inches of compost or mulch to help protect the plant if you don’t get a lot of snow. Be careful to use soil from another location, because digging soil up from near the plant should hurt its roots.
Before you start your winterizing, you should be sure to remove any leaves that are left dead on the plant. You should also pick up any debris that is lying on the ground at the base of your roses and dispose of it by burning it or putting it into the trash. Don’t compost any rose debris, because it can infect your roses again next year if there were any problems. You can prune any areas you want at this time.
Styrofoam cones are available for protecting roses through the winter. Although these are somewhat unsightly, they can do a good job of protecting the plants. You should tie each plant into a bundle before putting the cone around it.
Don’t fill the cone with straw or leaves until after the ground has frozen, otherwise rodents may burrow into it. You can also use plastic towers that are filled with water, or you can use chicken wire towers filled with straw or leaves to protect the plants.
In very cold areas, roses are often trenched for the winter. Old mulch is generally removed from the base of the roses to get rid of any potential diseases. Then the rose canes are tired together using a special synthetic twine that won’t decay.
A trench is dug on one side of the plant, and then a garden fork is used to loosen the soil around the plant. The plant is then turned over into the trench, taking care not to uproot the plant or break it.
Then the plants are covered with soil. In November, about 12″ of leaves are added over the top and watered to keep the leaves in place. In early April, the leaves are removed from the plants. Then in mid April, the plant is stood back up, reversing the original trenching process. This method is effective, but a bit dangerous.