Potted Knock Out Rose Care: How To Grow Knock Out Roses In Containers

Bright Pink Knock Out Rose
knock out
(Image credit: Diana Rever)

It’s easy to understand why Knock Out roses are so popular. They are easy to get along with, disease resistant, and they bloom all summer with very little maintenance. Pruning is minimal, the plants are self-cleaning, and the plants require very little fertilizer. 

Although they are often grown in the ground, container grown Knock Out roses tend to do just as well. Read on and learn how to grow and care for Knock Out roses in containers.

Growing Knock Out Roses in Containers

Follow these tips on caring for potted Knock Out rose plants:

  • Knock Out roses are best planted in spring, which gives the roots time to settle in before frosty weather arrives in autumn.
  • Ideally, your Knock Out rose container should be at least 18 inches (46 cm.) wide and 16 inches (40 cm.) deep. Use a sturdy container that won’t tip or blow over. Be sure the container has at least one drainage hole.
  • Fill the container with a high-quality potting mix. Although it isn’t required, some gardeners like to add a handful of bone meal for healthy root growth.
  • Potted Knock Out roses bloom best with at least six to eight hours of sunlight per day.
  • Feed the plant lightly every two or three weeks during the growing season, beginning after the plant has gone through one blooming cycle. Use a water-soluble fertilizer mixed to half strength. Don’t fertilize the plant in autumn when the plant is preparing for dormancy; you don’t want to generate tender new growth that is likely to be nipped by frost.
  • Water Knock Out roses in containers every two or three days, or more often if it’s hot and windy. Water at the base of the plant and keep the leaves as dry as possible. An inch (2.5 cm.) of shredded bark or other mulch will help keep the potting mix from drying out quickly.
  • It isn’t absolutely necessary to remove wilted roses, as Knock Out roses are self-cleaning. However, deadheading can make the plant look neater and may encourage more blooms.
  • Move container grown Knock Out roses to a protected spot when the temperatures fall below freezing. Although Knock Out roses are hardy plants that can tolerate cold as low as -20 degrees F. (-29 C.), potted Knock Out roses may be damaged in temps below -10 degrees F. (-12 C.). If you live in a very cold climate, move potted Knock Out roses into an unheated garage or shed, or wrap the plant with burlap.
  • Prune potted Knock Out roses when buds begin to swell in late winter. Cut the shrub down to 1 to 2 feet (31-61 cm.). Remove crowded growth in the center to allow sun and air to reach the center of the plant.
  • Repot container grown Knock Out roses as needed, generally every two or three years. 
Mary H. Dyer

A Credentialed Garden Writer, Mary H. Dyer was with Gardening Know How in the very beginning, publishing articles as early as 2007.