Most roses need some sort of winter protection. Right now (mid-November) the most important advice we can offer is “not yet”. The time to cover roses is after the first hard freeze shocks them into dormancy. Right now most roses are still active, and covering them too soon will do more harm than good. Let the last blooms of the season stay on the plant to form hips, slowing growth and encouraging dormancy. Roses should “harden off” in the cold for a few weeks.
Right now is the time to clean up the dead fallen leaves around rose plants and spray them with dormant oil or fungicide spray. This will help prevent diseases from taking hold during the winter or early spring. It’s best to wait until spring to fertilize and prune except for removing dead, damaged or diseased canes, which can be done any time. Additional pruning at this time of year is not harmful, however freshly cut canes will die back from the cut during winter so you’ll need to cut them again if you do it now. Another thing to do right now is make sure roses have enough water.
Once we’ve had a good hard freeze (the ground frozen for a few days) it’s time to cover your roses to protect from winter winds. Simply piling mulch around the base of plants will help protect roots. Any mulch will do, but we prefer pine bark rather than dyed mulches or fine-ground hardwood mulch. On our own roses we use pine nuggets. Pine needle mulch would be our second choice, but it’s quite expensive here in Ohio because of shipping cost.
You can protect plants better by building a wire cage around them with chicken wire or fencing. Fill the cage with clean straw or oak leaves. Oak leaves won’t mat down or get slimy, encouraging diseases and blocking air circulation like other kinds of leaves. Fungus diseases are roses worst enemy, so “clean and dry” is what you’re looking for in a mulch material. We have shredded pine bark in bags, and also bales of bright, clean straw, both of which work very well. Ideally spray the plants with all-season spray oil before covering them.
Roses located in protected spots like east-facing walls need less protection than plants growing in the open, where winter winds will dry them out quickly. Remember to remove the covering gradually next year as the weather warms, giving the new buds a chance to “harden off”. Beware of a late freeze, which can kill tender new growth that’s been protected all winter. See our column archive at www.goodseedfarm.com for some detailed guidance on pruning your roses. In most cases, late winter or early spring is the best time for pruning. As you add to your rose garden next year, look for “own root” (rather than grafted) rose varieties. These are hardier and require less coddling.
Steve Boehme is a landscape designer/installer specializing in outdoor living spaces. “Let’s Grow” is published weekly; column archives are online at www.goodseedfarm.com. For more information call GoodSeed Farm Landscapes at (937) 587-7021.