Winter can be tough on roses, and many tender species can suffer extensive damage, or even die if they are not protected from harsh, winter conditions. Even the hardiest of varieties will appreciate some tender love and care before the cold season hits.
Interestingly, your rose bush is less threatened by the cold, and more concerned about the freeze-thaw cycle. They will also need to be urged into dormancy. How to help them weather these extremes depends on a few key variables. Here’s how to prepare rose bushes for the winter cold, and which varieties to protect the most.
Prepare Them for Dormancy
Towards the end of the growing season, about six weeks before the first frost is expected, you want to start urging your roses into dormancy. All species of roses need to go dormant to rest up and save some resources before the next bloom cycle.
By late summer, the process of transitioning your roses towards dormancy should be well underway. It may seem too soon, but a long, slow process will help them get fully prepared for the cold, rather than only partially. There are a few key steps to perform to ensure they are prepared for the long, cold season ahead.
The first step of transitioning your roses is to stop fertilizing at the end of July or early August. You want to time it so any new growth will be mature by fall, just before temperatures start to really drop. You don’t want any new, tender growth to worry about once winter temperatures arrive for good, as the frost can affect the tender growth, and potentially kill the entire bush.
Around September, you can feed bone meal to your rose bush as it slow-releases calcium and phosphorus, which are good for root strength and overall plant health. Bone meal is low on nitrogen and potassium, which are more beneficial for greenery and blooms during the growing season.
One application is all you need to give your rose plant some proper nutrients just before dormancy.
Pruning and Deadheading
You should stop pruning by this time, which will also discourage any new growth too late in the season. Pruning encourages roses to produce, so once pruning has stopped for a long enough period, your rose bush will get the signal that they should start preparing for winter. They need to store this energy to make it through dormancy.
Gardeners will often dead-head any spent blooms to promote new growth during the growing season, but you want to stop this around the same time, as well. Leave the flowers and let them turn into hips, which is the fruit of the rose bush. This also tells the plant that it’s done growing for the season, and should prepare for sleep.
Do a Proper Cleanup
Check for any diseased parts of the rose bush, including pests. Some newer hybrid roses are bred to be less susceptible to specific diseases; however, older roses (heirlooms) tend to be the hardiest, toughest, and most disease-resistant, all around.
Your particular climate and garden space are also important characteristics to pay attention to during your clean-up. All roses are prone to blight, powdery mildew, black spot, and other diseases, which can form more easily depending on environmental surroundings and temperature.
Wet, damp conditions that don’t freeze can harbor leaf spot, but powdery mildew doesn’t need moisture to thrive, and can easily survive winter temperatures. While you can try and plant species that are resistant to specific diseases, a combination of garden cleanup and good sanitation practices in conjunction with disease-resistant varieties is your best chance at keeping problems at bay.
Remove any spotty or misshapen leaves from the plant and the ground once they’ve fallen, as disease can continue to spread from infected foliage.
A proper raking of the whole garden bed is recommended, especially following any other perennial plant clean-up you might do in the fall. Diseased canes should be pruned back to healthy wood in early spring, which will help reduce chances of canker.
Fallen leaves from nearby trees may not be the best mulch for your roses, even though they are often the easiest to find once fall arrives and can provide some nutrients for the soil. Wet leaves harbor mold and fungus, which roses are particularly susceptible to, and they also act as shelter for pests.
Packing soil around the base of the plant is a decent insulator for tender roses, just remember that the insulation should be removed once the spring comes, and excess soil is not always easily dispersed.
Wood mulch like bark and cedar chips are a good, basic medium to use in garden beds, but not for mounding around the base for winter protection.
Peat moss, straw, and brown yard waste like grass clippings and dry leaves are better to use at the base of rose bushes or inside rose collars. Compost and soil mixed together can also work, and be packed around the base for winter protection along with a cedar or wood mulch around the surrounding area.
Continue to water any rose bush well up until the ground is completely frozen. If there isn’t enough natural rainfall and moisture during the fall and early winter, make sure to do some supplemental watering.
If no rain is expected, it's especially important to water deeply after the first light freeze, and make sure to drench the soil completely so that water gets down to the roots.
Fall usually brings enough precipitation to keep them going through the winter, but if there is unexpected drought, continue to soak the ground on a weekly basis, right up until you can't any longer. Your roses will benefit from deep watering as it goes dormant through the winter.
The most dangerous part of winter for rose bushes is not necessarily the temperature, but the freeze-thaw cycle. When the plant goes through consecutive periods of freezing, then thawing, and refreezing again, it can get stressed out. Swinging between these extremes tricks the plant into thinking it should start growing again, and when a freeze hits, the plant suffers injury.
Heavy, cold winds quickly dehydrate rose plants, which will add to the damage. This is what you want to protect your plants from the most: dehydration during dormancy. A long, steady, cold winter with lots of snow can actually be a blessing compared to a dry, milder winter that dehydrates the plant, and puts it through fluctuating temperatures around the freezing mark.
Various tactics can help different species get through any freeze-thaw that may occur before the spring. The methods of protection that you decide to use depends on the species, how hardy it is, and the characteristics of your garden and climate.
Pack Around the Base
Most of your work happens once a few hard frosts have hit. At this point, you want to pack soil around the plant, usually around 6-12 inches high, depending on the size of the bush. This will protect the graft, which is usually at, or just above the ground, and can be spotted by the scarring where the union of the rootstock was attached. Mounding will also protect the roots.
In warmer zones that have mild winters, some gardeners choose to encircle the rose bush with a cage or plastic container. These circular collars are around six inches high and can be filled with leaves, soil, and other forms of mulch. Collars can be filled with snow once it arrives, as snow is an excellent insulator that protects the plant from winds, and the freeze-thaw cycle that is so damaging.
Note: try not to disturb the soil around the plant when you are packing around the base. Instead, add new soil, mulch or leaves, so as not to disturb the roots and bottom of the rose. Be careful not to use any leaves from a diseased or pest-ridden tree.
Climbing Rose Winter Care
Climbing roses are especially susceptible to winter damage, and if not wrapped properly, you will lose the canes by spring. New growth will emerge, as the plant doesn’t die, but it means you have to start from scratch every year in terms of growing a substantial plant.
If you want your climber to get bigger, you need to protect the canes. Wrapping them in burlap can help, but you can also pin them down to the ground and insulate them there. Wait until a few hard frosts have come and gone, and on a nice day when they are still pliable, secure them to the ground using landscaping fabric pins.
Dig a bit of a trench for them to lay down in, and push dirt over top. Cover with a thick layer of mulch, and remember to strip off any remaining foliage from the canes. This should help protect them until spring.
Hardy Rose Care
The majority of rose varieties will do fine up to zone 6, however, some are specifically bred for even colder climates. Many popular David Austin roses are hardy to zone 4 or 5, where gardeners have their choice of various hybrids or heirlooms. Others like “Knock Out”, “Snowdrift”, and “Little Mischief” hybrid roses will easily overwinter the cold temperatures in these zones.
Though it may be tougher to find rose bushes that can thrive in zone 3, there are indeed a few that are hardy enough. Anything descending from the Rugosa rose family is a sure bet, and one by the name of “Sunrise Sunset” can handle zones 3-9.
There may be others to add to the list, but be sure to do your due diligence when visiting garden centers that may sell roses unfit for your climate. Always check the tag before making any purchases.
Hardy roses won’t need as much fanfare when it comes to protection. However, you can still provide some winter care. Climbing varieties will benefit from having their canes tied together for wind protection, but you don’t need to use burlap or bury them.
Hardy roses will also benefit from the late summer transitioning towards dormancy, a clean-up of the beds and good sanitation, as well as deep watering up until the ground freezes completely, but mounding won't be necessary.
Late Winter Pruning
Depending on your growing zone, a late winter prune is the best way to ensure your rose bush comes out in early spring with healthy, new growth. Typically, this will be in March or April, but warmer zones may prune as early as January or February if spring comes earlier.
Ideally, you want to prune the rose bush back by about one-third, which is considered to be a somewhat hard prune. This practice will signal to the plant that it should start waking up.
Always use a sterile, sharp pruning tool and make angled cuts directly above a bud. Angle the cut so that the new growth grows away from the crown of the plant, and not inward. If done correctly, the bud just below the cut will produce new stems with lots of blooms.
Keep in mind that this kind of pruning is meant for roses that produce on new wood, and mainly include varieties like floribundas and most hybrid tea roses. Plants that produce on old wood may not need to be pruned until after their first flowering, and some, like miniature roses, may not require pruning at all.
For the best results, practice pruning techniques that best suit your rose bush, and if unsure, watch your plant go through a one-year growth cycle to see how, and when it blooms. For all plants, prune back and remove any dead or diseased canes around late winter or early spring.
Before Spring Prep
There are a few things to remember just before the warmer temperatures of spring arrive and the ground begins to thaw. Remove any rose collars, and disperse mounds of soil or mulch on tender varieties.
Leaving these protective elements can cause many issues including infection and diseases like rot and fungal issues from too much moisture, as well as housing for unwanted pests and creatures. If the mounds are still frozen, you can leave them until they begin to naturally thaw out.
Most of the work you do to protect your rose bushes during the winter doesn’t actually happen during the coldest months. Get in the habit of starting your winter care at the end of the summer, so that your roses can slowly transition into dormancy.
To ensure the best winter care, apply winter protection that best suits the specific variety of rose bushes in your garden. Your preemptive efforts, good sanitation practices, and protective measures will help ensure that your prized rose bushes reward you with beautiful blooms once another growing season comes along.