Tender varieties of roses can be seriously damaged in places where the temperatures dip below 20 degrees F. But there's an easy way to protect them with a technique called the "Minnesota tip." It was developed in the 1950s by a Minnesota gardener and involves tipping a rose bush into a trench.
- Prune the bush to three feet tall, cutting above outward-facing buds. Remove smaller limbs, leaving three to five of the thickest, most vigorous canes.
- If there are any leaves, pull them off. Aside from harboring disease, leaves can increase drying.
- Tie the canes together using synthetic twine that will not decay over winter. Tie by starting at the bottom with a slip knot and lacing up the plant. Leave a long piece of twine attached.
- Spray the canes with dormant oil spray, which protects them from diseases in the soil. Mix 5 tablespoons of the oil with 1 gallon of water. Or, if you've already made a baking-soda solution (1/3 cup baking soda to 1 gallon water) to spray as a fungicide, you can simply add the dormant oil to that to save time. Coat the canes well and let dry.
- Dig a trench on one side of the plant and loosen the soil around the roots using a garden fork to minimize root damage.
- Add fallen evergreen needles to the trench and mix with the topsoil. The high acidity of evergreens is great for rose beds.
- Use a garden fork to pry under the roots and carefully tip the plant over into the trench.
- Cover the plant completely with the soil that was removed, being careful to leave the long piece of extra twine exposed above the dirt (to help you find it later).
- Scatter moth balls around the top to discourage burrowing animals from disturbing the rose bush.
- Water the bed to help settle the soil and keep the canes and roots in good shape for the winter.
- Cover with a carpenter's blanket and bags of leaves to keep it in place. Bags of leaves are easier to deal with in the spring than loose leaves, but for small areas loose leaves may be fine and will decompose.
This process can be used for all varieties of non-hardy roses--from standard to miniature. By early April when days are warmer and longer, remove the leaves, and then a few weeks after that, uncover the bush, untie it and get it ready for a summer of beautiful flowers.
If you live in a zone where the temperatures get cold but stay above freezing, you can use these steps for all of your roses. In the warmest areas, roses never go into complete dormancy, but they do stop blooming and need very little winter attention.
Many gardeners prune their roses heavily at this time so they won't interfere with spring growth, but pruning is a matter of personal preference. You can cut back the canes to two or three feet high and remove any problem branches.
Most hardy roses come from Canada and are crown-hardy, which means that they can die back to the ground. In the spring, you can prune the dead wood above ground and the plant will come up again. To winterize hardy roses:
- Add a rose cone (available at garden centers).
- Poke holes for ventilation to prevent moisture build-up against the canes.
- Weigh the top down but leave it open.
- Push soil against cone to seal it. Once the shrubs are cut back, tie them with string. Wrap them in a circular way, just to keep them from being whipped in the wind.
- Mound the base of rose with 10 to 12 inches of soil. Get the soil from somewhere other than your bed. You don't want to be removing soil from the root base and exposing it to cold.