Although roses have a reputation as being fussy, or high-maintenance, they actually tolerate a wide range of conditions, and are worth the effort for most sunny gardens. For best results, keep in mind the following:
- They usually prefer an open site in full sun. This means a minimum of 5-6 hours of direct sun, and avoid crowding them against the house or other plants.
- Although the best time to plant is late-autumn or early spring, roses can be planted from nursery containers throughout the summer, if kept watered afterward.
- They do best in somewhat fertile, compost-rich, moist but well-drained soil. Before planting, amend soil with any well-rotted manure, compost, or Canadian peat moss, and mix well with your existing soil to a depth of about a foot. Mulch with 2-3 inches of wood chips, or shredded bark or leaves after planting, and soak thoroughly – twice.
- Tie the canes of climbers loosely but securely to a trellis, fence, or other sturdy support.
- Roses should be watered approximately once or twice a week through the growing season, depending on your soil, climate, and growing conditions. Roses should have a good, deep soaking to encourage deep root growth, and don’t want to go too dry between waterings.
- Water the soil at the base of the plant, and avoid splashing water on the leaves; avoid relying on lawn sprinkler systems, as they often don’t apply sufficient water, and getting the leaves wet will result in fungal disease.
- Apply a balanced fertilizer and organic mulch in early spring. In spring and summer, apply a balanced liquid fertilizer for flowering plants or rose food every 2-4 weeks.
- Spent flowers should be trimmed off routinely to encourage additional flower bud formation, unless rose hips are desired. Stop deadheading at the end of summer, to signal to the plant that the growing season is over. This will help ease it into dormancy at the end of the season.
Pests & Problems
- Fungal diseases such as black spot and powdery mildew are usually a result of conditions such as overhead irrigation, poor air circulation, and/or too much shade. Proper siting, pruning, and watering practices will prevent these problems better than any spray, but if necessary, fungicides may be used according to label directions. Apply these at the first sign of fungus problems, since they work as a preventative, not a cure.
- Insect pests such as aphids, Japanese beetles, or sawfly larvae are usually a nuisance at worst, and may be treated with insecticides according to label directions.
- Most roses sold commercially are grafted onto the rootstock of a more vigorous, wild rose for better growth. This rootstock may produce its own stems, or “suckers”, which should be trimmed off completely as they appear. These can be identified as any stems that originate below the graft union, which looks like a seam on the main stem, at or near the soil line.
- Overwintering roses is easier than most people might expect. First, don’t prune roses hard before winter (though very long stems may be shortened by 6-12 inches to prevent wind rock.) Leaving the pruning until spring will reduce winter dieback. We recommend simply piling soil or mulch on and around the base of the plant, to about 1-foot deep, to completely cover and protect the lower part of the canes. In cold northern climates, you may also pile your autumn leaves on top of this, to a depth of about another foot.
- Styrofoam rose cones are not necessary (or attractive), even in very cold climates, and can hold in excessive moisture and protect overwintering pests.
- When temperatures rise and the ground thaws in early spring, remove the mulch a little at a time, over a couple weeks, to gradually expose the canes; this is the time to prune.
- Pruning in northern climates should be carried out in early spring, after protective mulch is removed, but before the leaf buds open, at about the time Forsythia begins to bloom. Roses in warmer climates may need less pruning, and this can often be done earlier, in late winter.
- Dead wood can and should be removed at any time. Don’t leave stubs.
- Hybrid tea roses and grandifloras may be cut back to about a foot high. Remove all but 4-6 well-spaced, outward facing stems, and cut these back to an outward facing bud. In warmer climates, canes may be reduced to 1 ½ – 2 feet long. Remove any shoots thinner than a pencil.
- Floribunda roses should be pruned to 12-18 inches in early spring, cutting back to outward facing buds. Remove any shoots thinner than a pencil.
- Miniature roses should be trimmed back by 1/3 – ½ in early spring.
- Groundcover roses should be trimmed back in spring to outside buds, to accommodate their growing space. Shorten side shoots to thin out congested plants.
- Climbing roses should trained onto a support for the first two years by tying the canes loosely to the structure, and removing only dead or damaged stems. Starting in spring of the third year, trim back main stems to accommodate their support, if needed; side shoots may be cut back by 2/3, or to 3-4 buds.
- Shrub roses should be pruned lightly in summer, after flowering, by pruning back canes by up to a third, if needed, and trimming side branches by ½ – 2/3.