Choosing plants and shrubs that pair well with your Knock Out roses does more than beautify your yard. Surrounding Knock Out roses with compatible plants -- especially shrubs -- shelters the leafless roses during winter. Using evergreens also screens the bare branches during dormancy. Find plants and shrubs happy in the same growing conditions of full sun to partial shade, and averagely moist, mildly acidic well-drained soil. Select them according to colour and texture for maximum appeal.
Japanese falsecypress (Chamaecyparis pisifera) 'Cream Ball' is a rounded dwarf evergreen shrub. Mature, 2 feet high and wide dimensions make it a good edging choice for beds of 3- to 4-foot Knock Out roses. Its lush, white-tipped, pale green foliage contrasts well with Knock Out's cherry-red flowers, red-orange rose hips, and purple-green summer or burgundy autumn leaves. Evergreen winter heath (Erica carnea) 'Springwood Pink' has 6- to 9-inch mounds of needle-thin, bronze-tipped green leaves. Its slender stems bear dense clusters of bell-shaped, clear pink flowers between January and March. They fill the garden's colour gap while Knock Out is still dormant.
Perennial Blooming Plants
Think carefully before selecting perennials to grow with your Knock Out roses, because they will be permanent garden fixtures. Scabiosa (Scabiosa) 'Butterfly Blue' forms low clumps of deeply cut, greenish grey leaves. Each sturdy stem has a single, lavender-blue flower with flat petals encircling a centre of lighter lavender, bushy stamens. April-to-frost blooms provide continuing contrast to red Knock Out flowers. Intersperse clematis (Clematis tubulosa) between your Knock Out roses for a late summer, red, white and blue display. This fragrant, perennial subshrub has deep green compound leaves. In August and September, small, white-stamened, tubular blue violet blooms line its slender, 3- to 4-foot stems.
Scatter annuals among your Knock Out roses for changing garden look from year to year. Display Knock Out's red blooms and purple-toned foliage to their best advantage with a companion planting of Coleus (Solenostemon scutellarioides) 'Black Dragon.' Rich burgundy-centred leaves with purple-black, ruffled edges on the 12-inch plants will bring late spring to frost attention to the partially sunny or shady parts of your rose bed. For a solid mass of carefree colour, tumble 'Bravo Rose' petunias in sunny spots around the Knock Out plants. Standing 8 to 10 inches high, and up to 2 feet wide, they produce large, funnel-shaped, rose-pink blooms throughout the growing season. The fragrant flowers' white throats add a contrasting touch.
Edge your Knock Out bed with miniature roses for an all-rose theme. 'Ruby Ruby' stands 12 to 18 inches high. The mildly fragrant, disease-resistant cultivar has dark green, glossy leaves and abundant, double cherry-red blooms. 'Gizmo' has a spicy aroma and glossy green leaves. Its vivid, red-orange single roses -- with more than 35 petals -- will pair well with Knock Out's orange-red rose hips.