Are Gardenias Always White?

Conjuring up scenes of summer in the Deep South, the powerfully fragrant gardenia (Gardenia jasminoides), or cape jasmine, boasts glossy, dark green foliage and lovely single or double blooms with a waxy feel. A distinctly diverse group of cultivars varies in every aspect except color. All gardenia flowers are white, though they turn a creamy yellow as they age. The evergreen shrubs typically grow to 5 or 6 feet tall, and as wide, in U.S. Department of Agriculture plant hardiness zones 8 through 11

Flowers range from an inch to 5 inches in diameter. "Mystery" features large, pure white, formal blossoms -- the standard for florists' corsages. Double, rose-like blooms show up on "Veitchii" and "First Love," while "Kleim's Hardy" has single five-petaled flowers that resemble daisies. With as much fragrance as larger gardenias, the dwarf hybrid "Radicans," which usually stays under 2 feet tall, can be grown as a ground cover full of 1-inch white flowers. It also works well as a container plant. Perhaps the only time a gardenia displays a shot of color, "Mystery" sometimes retains its calyces (that join the flower to the stem) through the winter, which change from their summer green to a brilliant orange.

To keep the white blooms coming and the contrasting foliage lustrous, grow gardenias in acidic soil, high in organic matter, but well-draining. The bushes like moisture and mulches to cool their roots . Although most gardenias prefer partial shade, "Kleim's Hardy" can flourish in full sun. If gardenias have a downside, it is their susceptibility to garden pests, particularly sucking insects. These white-flowered shrubs are favorites of whiteflies, which leave a sooty mold on the leaves, giving them a dull, dark, splotchy appearance. Scale insects prey on gardenias, too. Control these pests with insecticidal soap and horticultural oil that are environmentally safe.

Traditionally, gardenias have been grown indoors in containers in colder climates, but they respond well when placed outdoors in the warmer months. When blooming inside, their intoxicating fragrance and shiny flowers bring cheer to any room. Gardenias need bright light, moderate temperatures and plenty of humidity. Water with room-temperature water, never allowing the plants to completely dry out. From March to August, fertilize with a liquid acidic solution. Following an old practice, cut gardenia flowers down to the stem and float them on water in shallow bowls to release their fragrance into the house.

The mounding habit of low-growing varieties, like "Veitchii," complement Asian-inspired gardens. Planted above boulders, they can be trained to spill down a slope. The dwarf variety "Radicans" might be used to cover bare ground in a shaded garden. Gardenia shrubs are also at home in cottage gardens. Grow several of them in a hedge or low screen. Solitary shrubs make good espaliers or specimen plants. Place a specimen gardenia near outdoor living areas so its fragrance can be enjoyed, and good air circulation there will help in keeping insect pests down. A gardenia can even be trimmed into a topiary.