There are over 150 species of roses, according to information published by the University of Illinois, and they vary widely in appearance and growth habits. Some types of these beautiful and popular flowers are climbing, while others grow as compact bushes or hedges. Some roses are cold-hardy, while others thrive in warm, humid temperatures. Regardless of the species, all roses, whether native or hybrid, old-fashioned or miniature, have the same basic growing requirements.
Roses need plenty of sunlight in order to thrive. A minimum of six to eight hours of exposure to sunlight per day is recommended by Karen Russ, a horticultural specialist with Clemson University. Morning sunlight is particularly important, as it quickly dries the dew from the leaves, preventing the development of the different types of fungi that can cause leaf spot.
Roses need rich, loamy soil in order to thrive. Plant roses in a location where air can circulate around the bush, and where they will not be competing with other plants for root space. Placing roses away from fruit trees can reduce the chances of disease developing, suggests Ms. Russ, and so does making sure that the soil is well-draining. A raised flower bed can offer both air circulation and good drainage.
Roses are heavy feeders and require a lot of nutrients in order to thrive. Mulching can help with that--add a 3-inch layer of pine straw, bark or other organic materials around your roses in the spring--but you should also fertilize your roses to encourage optimum growth. Fertilize in the spring, as the first leaves are appearing, and fertilize again after each cycle of blooming. Use a fertilizer formulated for roses, and water the rose before and after each application. Reduce the amount of fertilizer to half a dose in June, July and August. Cease fertilizing in September to allow the plant to go into its dormant state.
Roses are also heavy drinkers. Lack of water will lead roses to develop limp, yellow leaves that may even drop off. In some sensitive species, roses will simply stop blooming if they do not have enough water. Deeply water your roses frequently enough to keep the soil moist throughout the growing season. Use a soaker or drip hose, so that the water will seep slowly and deeply into the ground. Avoid wetting the leaves of the plant, as this can lead to fungal growth. Reduce watering in the fall and let the ground dry out a bit between each watering.
Roses that grow in bush form should be pruned every year to a height of between 12 and 24 inches, according to Cindy Welyczkowsky, a horticulturist with Ohio State University. In addition, suckers (canes that sprout from the roots) should be cut off below the soil. Most roses should be pruned in March, before new growth appears, save heirloom roses and climbers that bloom on last year's wood. These should be pruned after they begin to bloom.
Remove dead or dying wood first, then remove weak or crossing canes. Make clean cuts at a diagonal. If you live in an area bothered by boring insects, you may want to seal the wounds left by pruning so as to prevent the insects from entering your roses.