Calibrachoa, a prolific flowering plant also known as million bells, produces small, petunia-like blossoms from spring to frost in shades of white, yellow, pink, red, blue and purple. Gardeners value the plant for its mounding, trailing growth habit and ease of care in the landscape. Reaching heights of up to 10 inches and spreading more than 36 inches, calibrachoa makes an ideal ground cover in low-traffic areas. Grown as a perennial in USDA Hardiness Zones 9 through 11, calibrachoa performs as an annual in cooler areas. The plant tolerates temperatures as low as 23 degrees F, though it dies back completely below this point.
Choose a planting site for calibrachoa that receives full sunlight or light shade. Cover the planting site with a 2-inch layer of organic compost and till into the soil to a depth of 6 inches to improve fertility. Plant during early spring, just after the threat of freezing has passed.
Dig a hole in the soil of equal depth and width as the plant's container. Remove any old potting soil from the roots, and then insert directly into the hole. Cover with soil and water lightly to collapse any air pockets. Space calibrachoa 27 to 30 inches apart.
Water calibrachoa about once every five days during spring and summer to keep the soil consistently moist. Decrease watering to once every seven to 10 days during fall. Soak the soil to a depth of about 4 inches to ensure the plant receives adequate moisture.
Feed calibrachoa during early spring, just after planting. Apply a balanced 10-10-10 NPK fertilizer according to the directions on the label for the best results. Water the soil lightly prior to feeding to prevent root burn or injury.
Cut the plant back by several inches using sharp scissors immediately after flowering ends to promote fresh, bushy growth. The plant does not require deadheading during the flowering season, as the flowers fall freely.