Should I Cut Back Floribunda in Spring More Severely If It Is in a Pot?

Pot Size

• A healthy root network nourishes the rose's top growth. To eliminate the need for severe pruning in spring, choose a pot that accommodates the rose's roots comfortably. A classic floribunda, like "Iceberg" (Rosa "Iceberg"), hardy in U.S. Department of Agriculture plant hardiness zones 5 through 9, grows to a height of 30 inches, with a 26-inch spread. The lateral roots can be as wide as its crown, so select a container whose width matches the mature width of the plant. In the case of "Iceberg," that means a container with a diameter of 26 inches or more.

Spring Pruning

• Late winter or early spring is the optimal time for pruning floribundas and other roses, whether or not they are grown in containers. Normal pruning means cutting back canes by one-third or possibly one-half, if the rose is overgrown. Dead or weak canes and those that cross other canes should be removed at the same time. Trim the entire shrub to create an open, vase-like shape. Containerized roses have a heightened need for this because the practice promotes good air circulation, which is especially important to prevent fungal diseases.

Alternatives to Drastic Pruning

• A container-grown floribunda planted in an undersized pot will eventually become root-bound. If that condition is left to persist, the roots of floribundas and other roses will not be able to obtain enough nutrients from the soil, and the plant will die. Rather than pruning the plant hard, consider repotting in an appropriately sized container. Choose a pot that can accommodate a layer of drainage material in the bottom. Tease apart the rose's roots and spread them over the mounded soil before filling the new pot.

Plant Choices

• If space is a problem, or available container size is limited, curtail the need for annual hard pruning by choosing floribunda varieties accordingly. Larger varieties, like red-flowered Burgundy Iceberg, hardy in USDA zones 5 through 9, may have a spread of up to 36 inches, requiring a pot at least that wide. A smaller variety, like Julia Child, with yellow flowers and hardy in USDA zones 5 through 10, needs a pot only 24 inches in diameter.