Selecting a Container
Choose containers made of wood or of unglazed ceramic, because they can “breathe” and stay cooler than metal or plastic containers. The pot must have drainage holes, and be large enough to comfortably accommodate the plant’s roots. For miniatures or the smaller shrub varieties, a container 10 to 12 inches in diameter and 12 to 14 inches deep will generally suffice. For hybrid teas and floribundas, we recommend containers at least 16 inches in diameter and 16 to 18 inches deep.
Use a planting mix of 3 parts sandy loam soil to 1 part organic matter (or use a potting soil available commercially). At time of planting, add about 1/2 cup bone meal or superphosphate fertilizer to the planting mix.
Form a mound of planting mix on which the plant’s roots will rest. Position the plant so that the crown (the base where the canes join) is an inch or two below the rim of the container. Then fill the container with planting mix up to the crown. Press it down gently, then water thoroughly. The planting mix should finally settle about an inch or two below the rim, leaving a reservoir to facilitate watering.
During the growing season, a thorough watering twice a week should suffice. However, you should regularly monitor the moisture content by checking the planting mix. If you can feel no moisture an inch below the surface, it’s time to water.
After the new growth is off to a good start, fertilize weekly with a liquid plant food. Use half the recommended amount until the plant is growing well, then increase to the full recommended amount and use according to label directions.
Keep the plants in a sunny place where they receive at least 4 to 6 hours of sun daily. Avoid placing the containers next to light-colored walls, as excessive reflective heat and light may burn the foliage. During the hottest part of summer, take precautions to keep the roots cool. This is less a problem with woody or pottery containers, but roses in any container will benefit by being placed where they are shaded during the hottest part of the day.
Roses in containers can stand temperatures down to 28 degrees F. without protection or covering. If the temperature drops below 28 degrees, move the containers into an unheated shelter. Be sure they are not placed near a window, where warm sunlight might start plants growing. Water very lightly—only enough that the soil does not completely dry out—and don’t fertilize. When warm weather comes, put the containers outside and care for them as before.