There have been volumes written on how to grow roses, but for most home gardeners the rules are pretty simple: Choose the right plants for your soil and climate; keep them watered and fed adequately; give them enough air circulation and pruning to stay healthy; watch for pests and enjoy the beauty and fragrance of America's favorite flower.
Choose the right roses and the right spot. You can grow hybrid tea roses and other more delicate roses in Minnesota, but you will have to provide winter cover and a bit of fussing. If you do not want to do that, choose one of the many shrub, climbing, rugosa or old-fashioned roses recommended for northern climates. The University of Minnesota has done rose breeding over the years, and their Northern Accent roses—Sven, Ole and Lena—are pretty and hardy. The Northern Earth-Kind Rose Project is developing a list of great roses for our area, too. If you aren't sure what you want, ask your local nursery or garden center owner: they usually know which plants do well in our area.
Planting basics. Roses love it in the sun, so an area with six to eight hours a day of sunlight is great. They also need adequate drainage and relatively rich soil, so before you plant, amend the area with compost, cow manure or some other high-nitrogen fertilizer. Many Minnesota rose growers use Bob's Mix, an organic blend available through the Twin Cities Rose Club and a few retailers. You can also add some bonemeal to the soil. When planting, keep the crown about 1 inch below the surface of the soil.
Feed and water your roses. Roses need a fair amount of both water and food. Generally, they need the equivalent of one to two inches of rain per week. If you are supplementing rain, water the roses deeply, but not too often. Once or twice a week give them a good soaking, preferably in the morning. Direct the hose at the base of the rose, rather than on the leaves to prevent transmission of fungal diseases, and keep it gentle to avoid splashing fungi on the plants. There are many rose formulas of fertilizer available, but you can also use an organic fertilizer such as alfalfa meal or fish emulsion. Generally, fertilize shrub and other hardy roses in the spring and again after the first bloom. Hybrid tea roses need regular fertilizer, and many gardeners use the "weekly, weakly" method, meaning they fertilize once a week, but at half-strength.
Give them some air! Because roses are prone to fungal disease, they need plenty of air circulation. Plant them far enough apart to give adequate air circulation.
Pests. Black spot, powdery mildew, rusts, aphids, mites and the dreaded Japanese beetle. Yes, roses are susceptible to pests. However, proper watering (try not to splash!), air circulation and light, and good sanitation in the fall may prevent many of these problems.
What are your favorite roses?