Knock Out roses are an ever-blooming rose developed by Texas A&M University to withstand extreme Texas growing conditions such as drought, freezing temperatures and high humidity. Their popularity has spread as Knock Out roses are used in commercial and private landscapes as low-maintenance shrubs. Knock Out roses generally are care free, but occasionally, especially between blooming periods, old flowers, battered foliage and a few dead limbs can make the Knock Out rose bush look like it's seen better days. A little care helps revive your Knock Out roses.
How to Revive Knock Out Roses
Step 1: Remove Weeds Around Bushes
Remove weeds from around your Knock Out rose bush as far as 36 inches from the plant so that you can identify any weak or diseased limbs and see how to shape the plant. Rake old leaves and other garden debris from around the base of the plant.
Step 2: Prune Out Dead Wood
Prune out dead wood by cutting dead branches back to the point where they meet a main stem or point of origin. If the dead limb goes all the way to the ground without meeting a main stem, prune it at ground level. Pruning roses helps make the bush healthier for more vigorous growth.
Step 3: Shape the Knock Out Roses
Shape the plant by removing spent flowers and unruly growth by cutting limbs at a 45-degree angle and 1/4 inch above an outward-facing bud to train new growth outward. You can remove as much as half of a Knock Out rose bush when pruning, but severe pruning will delay the next blooming period for several weeks. This is because the plant blooms on new wood and requires a longer recovery period. Let a Knock Out rose grow the first season without pruning so it can get established in the landscape.
Step 4: Add Manure or Compost
Gently work two shovels of well-composted manure or compost into the top inch of the soil around the roots and apply a rose fertilizer according to the instructions on the package. Spread fertilizer just outside the root zone, not on top of the root zone, as it will burn new roots that are close to the surface. Water the compost and fertilizer well.
Step 5: Mulch Around the Bushes
Apply a 2-inch-deep layer of mulch around the base of the plant and 6 inches past the root zone. Leave a 1-inch space between the mulch and the trunk of the Knock Out rose to prevent mildew from spreading to the bush as the compost decays. Keep it evenly moist until new growth appears.
Step 6: Fertilize the Knock Out Roses
Fertilize the Knock Out roses regularly starting after the first round of flowering using fertilizer that's formulated for roses. Moisten the soil to protect the roots from burning and apply the fertilizer according to the package instructions. Stop fertilizing late in the summer to prevent new growth as the bushes prepare for dormancy.
Step 7: Transplant Knock Out Roses
Move your Knock Out roses to a more suitable location if the current growing environment isn't ideal. Knock Out roses need six to eight hours of sunlight daily to grow well. Ideal soil is neutral with a pH between 5.5 and 6.5. It's best to transplant the roses when they're dormant, ideally in late winter or early spring. Space Knock Out rose bushes at least 3 feet apart for good air circulation.
Jay Golberg is a certified Texas nursery professional and professional project manager. He has 30 years of business and farming experience and holds bachelor's degrees in English writing from St. Edward's University and finance from Lamar University.