Low-growing, mounded, bushy plants reach 12 to 16 inches tall, 12 to 14 inches wide and have a trailing habit. The white flowers are 1 1/2 inch wide and appear in 14 weeks from germination, blooming best in warm weather and long day lengths. Valued in shade gardens, it keeps its free-flowering habit even in shade and partial shade. It has medium- to bright-green, lance-shaped leaves with a medium texture that complements the star-shaped flowers.
"Silver Bells," like other members of the "Bell" series, is well suited for hanging baskets and containers, with the trailing habit lending itself to spilling over basket edges. Combine it in large containers with upright plants in the center and "Silver Bells" around the edges, since the white flowers go with any flower color. Butterflies and hummingbirds visit the flowers, so use it to lure these creatures within easy viewing range. In garden beds, use it in borders and as an edging.
Toward the end of summer while the plant is still growing actively, root cuttings to use as house plants through the winter. The Missouri Botanical Garden advises cutting back some garden plants in fall, putting them in small containers and bringing them indoors. Locate them in a warm area with diffused sunlight. Rotate the pots one-quarter turn weekly to keep the growth even.
Pinch "Silver Bells" back lightly to renew growth and flowering, and to keep the plant to size. Use a well-draining potting mix for container plants and keep the plants evenly moist but not soggy. Apply a balanced liquid fertilizer such as 10-10-10 monthly at the rate of 1 tablespoon per gallon of water. Overfertilization with nitrogen promotes leafy growth at the expense of flowering. Start plants from seed eight to 10 weeks before the last frost date, but do not cover the seeds with potting mix since they need light to germinate.