How to Care for Knockout Rose Bushes

Dig a hole twice the size of the root system of the rose bush. Add a layer of organic compost and peat moss at the bottom of the hole, recommends the website To Build a Garden. Place the knockout rose at the same depth it was in the nursery container. Backfill firmly and water deeply. Space bushes 4 feet apart.

Water rose bushes slowly, soaking the soil 12 to 18 inches deep, recommends Texas A&M University Extension. Water twice a week to ensure continued blooms throughout the growing season. Water with a soaker hose early in the morning, making sure not to get the foliage wet.

Apply a 2- to 4-inch layer of organic mulch around the ground of the bush, making sure to not touch the stem. Touching the stem can cause "diseases flourishing from excessive humidity," according to the U.S. Department of Agriculture. The mulch will prevent weeds and keep the soil moist and cool.

Feed the knockout rose bush with a rose-food fertilizer once a month. Scatter 1 cup of fertilizer on the ground around the bush without touching the stem. Water deeply to ensure the roots receive the fertilizer.

Prune any dead foliage and blooms during the growing season, as well as any necessary pruning to keep the bush neat. In the early spring, prune back to 12 to 18 inches to ensure new growth in the growing season.

Protect during the winter months by placing more mulch around the ground to keep it warm and placing a burlap bag over the bush tied with twine.