How To Revive Knockout Roses

Knock Out (​Rosa​ Knock Out®) is the name of a series of ever-blooming rose cultivars developed by Will Radler at 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 a Knock Out rose look like it's seen better days. A little care helps revive your Knock Out roses.

1. Remove Weeds Around Plants

Remove weeds from around your Knock Out rose plant as far as 36 inches from the base 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.

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 plants healthier for more vigorous growth.

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 plant 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.

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 and, ideally, at the recommendation of a soil test. 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.

5. Mulch Around Plants

Apply a 2-inch-deep layer of mulch around the base of the plant, extending 6 inches past the root zone. Leave a 1-inch space between the mulch and the trunk of the Knock Out rose to prevent potential diseases from spreading to the plant. Keep it evenly moist until new growth appears.

6. Fertilizing Knock Out Roses

Fertilize 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 or following the recommendations of a soil test. Stop fertilizing late in the summer to prevent new growth as the plants prepare for dormancy.

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 roses at least 3 feet apart for good air circulation.