Developed for disease resistance and maintenance, the Knock Out rose makes an excellent choice for any landscape. The plant blooms prolifically throughout the warm months. The fragrant flowers come primarily in shades of red and pink, but newer varieties include shades of yellow and white. The tidy, upright shrub grows through USDA zone 5 to a height of 3 to 5 feet. Plant Knock Out roses anytime during their dormant stage, but early spring gives the best results.
Choose a planting site. The site should receive a minimum of four hours of direct sun, but six or more gives better growth. In areas with cold winters, a sheltered location protects the plant, such as the south side of a structure, fence or wall.
Amend the soil with high-quality compost. Spread a 3-inch layer over the planting site and work it into the top foot of soil with a shovel. Knock Out roses prefer a fertile, well-drained soil. They do not do well in damp, waterlogged conditions. The compost improves drainage and adds nutrients.
Test the soil’s pH. Kits are available at home or garden stores. Knock Out roses grow best in a pH around 6 or 7. Add a rose fertilizer as needed to adjust the pH.
Dig the planting hole. Make the hole large enough for the roots to spread if your are planting a bare-root Knock Out rose. If planting a potted rose, make the hole big enough to place the rose with all of its soil into the hole. Dig the hole deep enough for the crown to sit just above soil level.
Place the rose into the hole. Adjust it to the desired position, keeping it straight. Spread the roots on a bare-root rose on a small mound in the center of the hole. For a potted Knock Out, gently loosen the roots after removing from the pot. Backfill the hole with the soil halfway and fill with water. After the water settles, fill in the hole the rest of the way with the dirt. Tamp down the soil.
Spread a 2- to 3-inch layer of mulch around the Knock Out rose. Keep the mulch from touching the base of the shrub.