Gardenias are the scent of summer

Published 12:00 am Friday, June 10, 2011

SALISBURY — The fragrance of a gardenia bloom is one that cannot be mistaken.
Winter daphne is the only shrub that would rival this elegant shrub. The fragrance of the shrub can permeate a landscape, noticeable, in some situations, even while driving.
Gardenia jasminoides is an evergreen shrub that varies in heights from 2 to 6 feet, depending on the cultivar. Its spread is generally about the same, but compact cultivars are often small enough to incorporate into planters.
The plant has a medium growth rate with glossy, dark-green foliage 2 to 4 inches long and half as wide. The flowers are waxy and white, although some cultivars may be yellow. The bloom can be single, double or star-shaped. Some blooms may grow 4 inches across. The flowers bloom over a long period of time, from May through July, and as mentioned, are very fragrant.
Gardenias grow best if planted in filtered or light shade, free from tree root competition. The shrub also does well as a potted plant. Gardenias prefer slightly acid, moist, well-drained soil with plenty of organic matter.
Mulch gardenias heavily and apply fertilizer in mid-March, using an azalea plant food, fish emulsion or blood meal, and again in late June to encourage extra flowers.
It is very important not to fertilize gardenias in late summer or early fall. Late fertilization stimulates tender growth of this and other cold sensitive shrubs. Older cultivars are often killed when winter temperatures drop below 15 degrees.
Irrigation is necessary to keep the plants in good condition, enabling the plant to withstand winter weather.
Gardenias are not without problems. Sooty mold is a black mold that coats gardenia leaves which is usually due to an infestation of aphids or whiteflies. While eating, they excrete excess moisture in the form of honeydew and this, in turn, supports the growth of a black fungus.
Insecticidal soaps and summer oils have been successful in controlling both aphids and whiteflies.
Below are cultivars available at local nurseries.
• August Beauty grows 4 to 6 feet high and blooms heavily from mid-spring to fall.
• Chuck Hayes is an extra hardy type, growing to 4 feet high with double flowers in summer.
• First Love is larger than August Beauty with large flowers in spring.
• Golden Magic reaches 3 feet tall and 2 feet wide, and has golden yellow flowers.
• Kleim’s Hardy is hardy to 10 degrees and grows to 3 feet tall with single flowers in summer.
• Mystery is the best-known selection. It has 4- to 5-inch double white flowers and can reach 6 to 8 feet.
• Radicans grows to only 12 inches tall and spreads 2 to 3 feet, with small, dark green leaves and inch-wide double flowers in summer.
• Daisy is a more recommended cold hardy variety.
Darrell Blackwelder is the County Extension Director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County. Learn more about Cooperative Extension events and activities by calling 704-216-8970 or online at