Cultural Problems with Roses
Miscellaneous cultural problems with roses are often difficult to diagnose and sometimes difficult to treat. Since symptoms of these problems and treatment are not definitive, a general discussion of what can be causing problems for your roses and how to stop the problem may be helpful.
Rose plant is wilting may be due to excessive heat, which can stress any plant. The plant is using a tremendous amount of food and water in extreme heat and the foliage just can’t keep up. Make sure your rose bush is getting adequate water without over watering, the roots don’t like consistently wet soil. And don’t feed or prune until the heat passes. You may want to construct a shade screen that will reduce direct sun exposure in the hottest part of the day to minimize the stress on the rose. This can be done with burlap or fabric fixed to wood stakes, or just put a beach umbrella up. Wilting can also be caused by too much water. Unusually long periods of rain may waterlog the soil, eventually leading to root rot. There is very little you can do once the problem exists, but planting originally in very well drained soil will help prevent the problem. Finally, do check the entire plant carefully for any sings of disease or insects. Treat appropriately as described in the previous page.
Rose canes are dead in spring is likely due to winter kill. Your rose may need to be protected from winter completely, right up to the rose can tips. Or perhaps you just winterized your roses too late. An early freeze could have caused significant damage to young growth. To minimize winter damage do not feed or prune too late in the season, which will encourage new growth. Many northern gardeners simply expect some winter dieback and prune it out in spring once growth begins.
Rose growth is slow in spring can be caused by a number of things, but slow to get going always worries us. The soil may simply be taking longer than usual to warm up because of cold nights, shade beginning to encroach on the garden, or you left winter protection on longer than usual. Leaving your winter protection on too long is much better than removing it too early. Not enough water can cause your rose bush to get going slowly. Perhaps there was not much winter snow or precipitation, or not enough spring rains yet. If that is the case, start a weekly watering schedule early. If growth is slow in spring and you had a lot of dieback from winter, be sure to prune out all dead canes. Until all dead plant portions are removed, the rose bush is working to restore itself. Prune canes back until you see healthy green or white stem material. If it is brown or hollow in the middle, keep pruning. Once all dead material is completely pruned out new growth should be more vigorous.
Rose bush or climber is not blooming but may otherwise be healthy and growing vigorously. It is likely you are over fertilizing. A lot of nitrogen will result in beautiful fast growing foliage, but sometimes no flowers. Be sure to fertilize according to the needs of your rose and package directions. You might also want to do a soil test to make sure pH is below 7.5 and other nutrients are not lacking. Improper pruning can also result in no blooms. Climbers that bloom on old wood, so be sure to prune only immediately after flowering. If your rose was grafted, it is also possible that the graft died. The rootstock used may be producing very vigorous, very thorny thick canes but no blooms.
Rose blooms are completely different than they used to be is usually because your grafted rose has died, probably from winter freezing. The rootstock is now growing, producing a completely different plant. If you seem to be growing two different roses on the same plant, it could be that the rootstock is simply producing shoots. Gently remove soil from around the plant until you can see roots. If there is growth from the roots themselves, prune it out all shoots and stems originating below the graft point. Replace the soil and hopefully the rootstock growth will stop, but you may need to prune out the growth once in a while.
Young foliage or new growth is discolored or dies could be due to a number of issues. You could be over watering and “drowning” the roots, which prevents them from taking up important nutrients. You could be over feeding with chemical fertilizers, which leave behind excessive soil salt. Chemical fertilizers should really be supplemental only, start using compost and amending your soil each season or use organic fertilizers only as directed. If you have been using chemical fertilizers heavily, stop. Then flush the soil by watering the rose plant heavily on two consecutive days. You might also want to check your soil pH. Alkaline soil over 7.5 may be the culprit. If your soil is too alkaline you will need to amend it every year by adding just a cup or so of sulfur around the rose bush. In the meantime, use an acid based fertilizer just until the foliage becomes healthy green again.
Rose blossoms wont open is often due to cool damp weather. The buds may partially open and stop or fail to open at all. Whatever may be causing this, it is usually best to remove the buds and dispose of them. If it is only due to temporary damp cool weather, your new buds should open normally. If the buds were infested with a damaging insect, you will have removed a great number of them by destroying the buds.
Rose plant is leggy or gangly, or is not producing blooms is usually because the rose is not getting enough sun. Most roses need a minimum of 6 hours of direct sunlight a day. Perhaps surrounding shrubs or trees have grown larger and are casting more shade on your plants. You may need to either prune the surrounding plants or move your roses to a sunnier location.
If you cannot figure out what the problem is with your rose, talk to a trusted local garden center or your local university extension service. If possible, bring a cutting of your rose bush that displays the symptoms. If you follow good watering and fertilizing practices, keep your garden free of debris, and inspect your rose bushes frequently you can usually minimize problems.