When it comes to getting your garden ready for winter, some plants will need a bit more of your help. Roses especially benefit from some extra TLC, since most of today's hybrid tea, grandifloras, and floribundas are grafted, meaning that a branch from one type of rose was attached to the stronger, more disease-resistant base of another type. The joint where the union was made needs extra protection from freezing temperatures, as the grafted-on growth could die completely, leaving you with growth from the roots, which won't be as attractive. Plants also can be pushed out of the ground during winter's freeze/thaw cycles.
How to Winterize Roses
The winter prep you'll need to do depends on the coldest temperatures you get in your region and which kind of roses you have in your garden. But all varieties will handle the cold weather better if you water them well in the fall, before the ground freezes.
Preparing Roses for Winter in Cold Climates
In areas where winter is mild, but the ground still freezes (usually Hardiness Zones 6 and above), follow these steps to give your roses a little extra protection.
- In early fall, stop cutting your roses and let the plants form hips (seedpods) as they being to prepare themselves naturally for winter. If you prune the hips while temperatures are still warm, they may try to produce tender new growth that could be zapped during a cold snap.
- After the first frost in fall, and when night temperatures dip into the 20s, protect your plants from freezing and thawing cycles by piling soil over the bases. Cover the bud union (a swollen, scabby-looking area on the main stem where the graft was made) and up to about a foot of the plant. Use fresh topsoil or compost, not soil scraped from around the plant, and pile dry, shredded leaves or bark chips over the mounded soil.
- Prune overly long canes on bush-type roses to prevent wind damage. Trim these stems back to about a third of their length, making your cuts just above an outward-facing bud, where new growth will appear in spring. Expect a certain amount of winter kill (when stems die back from the cold and won't produce new growth in spring). Remove the dead canes in early spring—they'll look brown, rather than green.
- In spring, remove the leaves or bark and the soil you piled around the base. Spread the leaves and bark around the garden.
Protecting Roses in Extra-Cold Climates
In northern areas, where winter means sub-zero temperatures and frigid, drying winds, you may need to take more extreme measures for your roses to survive.
- After the first frost, remove any remaining leaves, cut the stems back to three to five of the thickest, healthiest ones, and trim them back to about a foot tall.
- Dig a trench to one side of the rose large enough to contain the entire plant.
- Use a garden fork to gently loosen the plant's roots enough so you can tip it on its side and lay it in the trench.
- Cover the rose with soil. Pile a 2-inch layer of shredded leaves on top of the mound.
- In early spring, carefully uncover the rose and replant it.
Tree Rose Winter Protection
Standard roses have their graft union near the soil line, making it easy to protect the most important part of the plant. Tree roses, however, have their graft union a few feet off the ground. Follow these steps to adequately protect them.
- In mild-winter areas, pile straw around the base of a tree rose. In cold-winter areas, use soil instead of straw; soil will provide more insulation.
- Place a framework of wooden stakes around the tree.
- Wrap a generous length of burlap around the stakes to enclose the tree. Secure the fabric using twine or wire.
- Fill the enclosure with dry leaves or straw. In extremely cold areas, treat tree roses as you would other roses, by burying them in trenches.
Winter Protection for Potted Roses
Overwinter potted roses by moving them into an unheated garage or to a sheltered place next to the south side of your house. In regions with extra-cold winters, protect each plant by placing it, pot and all, in a roomy cardboard box and packing the box with shredded newspaper or dry leaves. Surround the box with bales of hay.
Plan early to protect your roses from the potential damage caused by freezing and thawing cycles in the winter. A little early preparation will go a long way in helping your plants to survive the coldest months of the year.