Hardy shrub roses are growing in popularity as gardeners discover they can be planted almost anywhere in your landscape you would plant any other shrub. They come in a wide variety of colors and have the appeal of hybrid tea roses without the high maintenance. Blooming varies from one-time bloomers to repeat bloomers (spring and fall) to continuous bloomers. Most shrub roses have excellent floral quality, fragrance, winter hardiness, and many are highly disease resistant. They typically grow from 2-6’ tall and can be used as specimen plants or trained as a hedge. Larger roses can be used as climbers on a trellis or a fence.
Sunlight – Shrub roses need full sunlight. 6 hours per day is minimum sunlight to be considered full sun. If your roses receive less than 6 hours of sun each day, they will be weakened, have fewer flowers, and will be more prone to diseases. The best location to plant a rose is a southeast exposure that receives late afternoon shade since dew remains on the leaves longer with morning shade promoting disease. Good air circulation around the plant is also necessary to reduce disease.
Soil – Shrub roses thrive best in well-drained soil. Work peat moss into sandy soils or sand into dense soils before planting to improve drainage. They prefer a slightly acidic soil. Shrub roses in alkaline soils will develop a yellowing of the leaves.
Planting and Care
When – Potted roses can be planted anytime during the growing season; however, spring planting allows the roots to become more established before winter.
How – Prepare the site by removing all other vegetation, either with a rototiller or by removing the top couple inches of soil at the planting area. Improve the planting site with organic matter. Compost is one of the best sources of organic matter and it is readily available. Composted manure is great for soil amendment; however, make sure it is well-aged so it doesn't burn the roots. Roses are heavy feeders, so be generous with compost.
Dig the hole for your rose 1 foot wider either side of, and 1 foot deeper than the size of the pot holding your rose. Keep the topsoil from this hole. Use some well-cured compost or very good black soil and mound up the center of the hole to be a base for your rose. Mix the topsoil that you took out of the hole with well-cured compost or very good black soil and one-half cup of bone meal to encourage root growth. Blend this mix well. Place the plant in the hole to a depth that will keep all the roots about 1/2 inches below the soil line after the hole is filled in. Refill one-third of the hole with the soil mix, and lightly firm the soil around the plant. Then fill up the rest of the hole with the remaining soil and gently press down. Leave a slight "dish" around the plant to help hold water.
Slowly pour about two or three gallons of water around the base of the plant. If the water runs away from the plant and is not soaking in, make a one-inch-high wall of soil around the edge of the planting hole. This will keep the water from running away and allow it to soak in around the plant. The most important thing you can give your new rose is water. Water will settle the soil around the root system, and water is needed to transport nutrients to the plant.
Spacing – Shrub roses can vary widely in size so space plants according to their mature size. Plants that will reach 6’ when mature should be spaced 6’ apart when used as individual specimens, closer if part of a hedge.
Watering – Roses require lots of water. Just after planting, treat your new rose as if it were still in the pot. It takes time for new roots to grow into the fresh soil of its new home. BalsamPath roses, when growing in their pots, are watered every day. After planting, water your new rose thoroughly every day for a couple of weeks, then cut back your watering to once every 3 to 4 days for a couple of weeks, and then water enough to equal 1 inch of rain, once a week. This is especially important during the first growing season of a newly planted rose. Light, frequent watering is not recommended. Instead, thoroughly soak the soil to a depth of 15-18” once a week. Watering at the base of the rose helps keep the foliage dry and helps prevent disease. Overhead watering is best done in the morning so the rose has a chance to dry during the day.
Mulch –Mulching helps retain soil moisture, keeps the soil temperature cool, decreases erosion, and reduces weeds. Using 2-3” of wood chips, straw, or grass clippings (not treated with chemicals) improves the soil as breakdown and decay occurs. Wet the soil before you apply the mulch to prevent the mulch from absorbing the soil’s moisture.
Fertilizer – Fertilization varies depending on the type of rose. Generally, apply limited fertilizer the year of planting. Spread the fertilizer in a band at least 6 inches from the plant’s roots, work it into the soil, and water thoroughly. All roses should get a second application at the completion of spring bloom. To encourage repeat flowering, a third application can be applied in late July. Do not fertilize after August 1 because it will promote new growth and delay cold hardening.
Weeding – Keep your rose well weeded. Mulch will help reduce weed growth and ease weed removal.
Deadheading – Removing spent rose flowers discourages the formation of rose hips and encourages the continuous flowering of roses. Deadheading also gives the plant a cleaner appearance and allows it to maximize its vegetative growth. Stop deadheading in the fall if you want to take advantage of the fall hip display.
Winter Protection – Some winter injury is expected. Even the hardiest of roses can exhibit some cane injury. Water plants well in the fall after the leaves have turned but before the ground freezes. After a hard killing frost, remove all dead or diseased canes and leaves and rake up all debris. When the ground is frozen, mound new plants with whole leaves, straw, or evergreen boughs, and for all roses, be sure it is well covered with snow.
Pruning – Shrub roses need little pruning although it is best to remove dead and unhealthy branches. Removing older canes also opens the center of the plant for new cane formation and improves air circulation. Up to one third of canes can be removed each year. Prune above the bud eye. Pruning to an inward facing bud will allow a taller plant while pruning to an outer facing bud will allow for a wider bush.
Insects – The most common insects to attack roses are aphids, mites, stem borers, and gall wasps. Occasionally leaf miners, leafhoppers, and thrips will also be present. Light infestations of aphids and mites can be washed off with a garden hose. Remove galls to control wasps, and remove infected canes to control rose stem borers. Nearby wild roses may also contribute to some insect problems.
Diseases – Many shrub roses are disease resistant but disease resistance does not mean disease proof. If susceptible varieties are planted, one must either carry out a spray program to treat disease problems, or live with blemished rose plants. The most common and noticeable diseases affect the leaves and include black spot, powdery mildew, leaf spots, and rust. Black spot is recognized by raised, purplish spots on the canes and remains on infected plants over the winter. Powdery mildew, seen as white, powdery patches, causes leaves to fold inward and become distorted. To reduce diseases, prune out diseased canes in early spring, rake up fallen and yellowed leaves, provide good air circulation to diminish the accumulation of dew on the leaves. Also, water plants near the roots, not over the leaves, to eliminate the splashing of disease organisms.