The precise method for bringing your rose bushes out of hibernation in spring and preparing them for the growing season will vary somewhat depending on your region and on the type of roses you own. For gardeners in frost-free zones, roses may be entirely evergreen, and "unwinterizing" may simply be a matter of some moderate pruning and extra fertilizer to jolt them into more vigorous growth. For gardeners in very cold zones, though, you may be digging up roses that were completely tipped over and buried in the ground for the winter.
Still, there are four steps that most gardeners will go through in some fashion to resurrect hybrid roses and prepare them for summer blooms. Roses have a reputation for being challenging to grow, but the reality is that most will keep growing and blooming even when a gardener neglects them. But proper early season steps can ensure that you'll have fewer problems to navigate during the growing season.
Remove Winter Rose Protection
In most cold-weather growing zones, hybrid roses will have been protected in some fashion against the winter cold, and early spring is typically the time when this step is reversed to remove any winter rose protection you applied last fall. This should be done when you have confidence that the weather will no longer create freeze-thaw cycles that will kill tender roses. It is not the cold weather alone that kills roses, but rather repeated freeze-thaw cycles that badly damage the plant tissues.
In fact, the act of covering roses is not about protecting them from freezing, but rather it is intended to keep roses frozen until there is no longer any danger of the weather cycling back and forth from frost to thaw. Don't uncover your roses until you're sure that warm days will no longer be interrupted by freezing nights.
In some colder growing zones, gardeners routinely cover up the entire rose bush with a cage or bags of dried leaves or straw. These cages and the covering material should be removed about the time the spring tulips and daffodils have begun to bloom. Rake off the soil or mulch that was used to protect the graft union, and remove any debris or leaves that were used as insulation over the ground. Exposing the graft union will allow you to spot any growth that sprouts from below. Stems that grow from below this point are from the wild rootstock and will not produce the prized blooms you're after.
In very cold growing zones, hybrid roses are often wintered by trimming and binding up the canes, digging a trench and bending the entire bush over into the ground, and covering it up with soil and mulch. If this was your winterizing method, now is the time to rake away the mulch, dig up the roses, and bend them back upright. Make sure to tightly pack the soil around the roots to support the bush, but make sure to leave the graft union exposed.
With rambling, climbing roses, the winterizing process involves laying the long canes out flat on the ground, pinning them down, and then heaping soil and mulch over them. In spring, reverse the process by carefully raking away the soil and mulch, unpinning the canes, and securing them once more to the supporting fence or trellis.
Prune Your Roses
You may have trimmed your roses back as part of the winterizing process, but if this step was omitted in the fall, early spring is an ideal time to inspect the bushes and make any necessary pruning. Even if you did some amount of pruning in the fall, it's likely the tips of canes have died back somewhat, requiring additional pruning. Pruning before the leaf buds open causes the rose bush to put its full energy into new growth.
Using sharp pruners, cut back each cane in short segments until you remove all dead wood and reach the green, growing wood. How much you prune away will depend on the severity of the winter, but even if you must cut back nearly to the level of the root graft, your rose will likely recover.
Warm climates: Spring pruning in warm climates can start in January. Gardeners in areas that don’t necessarily freeze during the winter but still have a prolonged period of cold weather can prune according to the type of rose they are growing.
Roses grown in areas with warm winters, like Florida and Southern California, don’t necessarily need to be pruned at all. But doing some thinning is advisable, and always remove any dead or diseased wood.
Another technique that gardeners in warm areas can try is to remove all the leaves from their rose bushes when they do their spring pruning. This fools the rose into a brief period of dormancy and lets it start fresh for the season. It’s also a good way to ensure you get rid of lingering diseases and insect eggs. Be sure to rake and remove all debris from the rose bed.
Cold climates: Roses grown in areas that get freezing winter temperatures should not be pruned until about April, or the canes could suffer more winter damage. Once the leaf buds begin to swell on the bush (usually around the time forsythia bushes start to bloom), it's safe to prune your roses.
Feed the Rose Bushes
As with most plants, roses enjoy a good feeding in the spring after they've begun actively growing. You can give them their first fertilization at pruning time. There are several good rose foods that you can use, but a general all-purpose fertilizer will also suffice. Slow-release fertilizers will need to be applied less frequently than water-soluble fertilizers.
Many rose gardeners also like to give their roses a handful (about 1/4 cup) of epsom salts at feeding time. Whether the extra dose of magnesium really benefits the plants has never been proven, but many experienced gardeners swear by it.
If you prefer to mix your own rose food, you can balance ingredients such as:
- 1 cup cottonseed meal
- 1 cup bone meal or superphosphate
- 1/2 cup blood meal
- 1/4 cup epsom salts
Spread the mixture around the perimeter of the rose bush, at the drip line, gently scratch it into the soil, and water thoroughly.
Spray for Diseases and Pests
Unfortunately, roses tend to have a proclivity for fungal diseases. Hopefully, you’ve chosen roses that are disease-resistant and suited to your area, but it's very hard to prevent all fungal diseases on these plants. Preventative spraying in the spring is something to be considered, even for roses grown organically. Lime sulfur is a good choice for spring spraying. It will generally kill any fungus spores like black spot that may have overwintered. An additional spray of horticultural oil will help to smother any insect eggs and larva.
These spring rose care efforts should get your roses off to a good, healthy start for the season. In addition to pruning, fertilizing, and spraying, make sure your roses get plenty of water, and monitor them regularly for signs of problems. The care you take in spring will reward you all through the growing season.