Growing roses is not difficult if you follow some basic rules. Roses need plenty of water and they need at least six hours of sun each day. More importantly, choose roses that are right for your area. There are 11 climate zones throughout the United States, Canada and Mexico, but each state or area may have two or three zones. Find out the zone you live in before selecting roses.
Plant Hardiness Zone Map
The United States Department of Agriculture and Arnold Arboretum from Harvard University developed the "plant hardiness zone map." The map is the result of years of compiling data “that tracked the average low (coldest) temperatures in various regions throughout the United States," according to Rose Gardening 101. Zone 1 is the coldest temperature, which drops to minus 50 degrees Fahrenheit and is located in northern parts of the United States and Canada. In zone 11, the lowest temperature is above 40 degrees Fahrenheit and is located in southern areas and Mexico.
Finding Your Zone
The Plant Hardiness Zone Map is located on various sites including the U.S. National Arboretum website. The zones on the map are identified by different colors. Click the area or the state you live in, and the map will zoom in to that area. Identify your specific area by the color. A chart will define the average coldest temperatures for your zone, as well as give you examples of cities in that particular zone.
Zones 2 to 4
Some roses are hardier than others are; therefore, they can survive colder climates. Hardy roses can tolerate zones 2 to 4 because they "tend to be vigorous, are relatively disease tolerant, and require little long-term maintenance," according to the University of Minnesota Extension. Rugosa roses are a type of shrub rose that can withstand the cold northern winters, as well as the salt used along the main highways. Other hardy choices are Canadian hardy roses, which include bush and climbing roses. Hardy roses, though, should be winterized because of the severe weather.
Zones 5 to 9
Zones 5 and 6 still have cold winters. It is important to winterize your roses by adding mulch. Zones 7 and 8 can get a freeze and possible snow, as well. Zones 7 and 8, however, are excellent zones for a large variety of roses including hybrid roses and tea roses. Zone 9 has cool, wet weather, which can bring on fungal disease. The Knock Out rose is a brand of roses developed by William Radler. Not only can they grow in areas as far north as some parts of Canada and as far south as Florida, Knock Out roses are disease resistant and a good choice for zone 9.
While hardy roses are the best choices for zones 2 to 4, other roses can survive cold climate zones if you take extra precaution before cold weather. Cut back plants to 3 feet and tie the tips together. This will protect the plant from wind and ice. Add loose dirt around the plant and top with mulch such as bark, wood chips, leaves or straw. For delicate roses, consider putting a protective cylinder over the plant. During the heat of summer, especially zones 7 to 9, consider shading your roses with an umbrella or other device.