Plant type: Evergreen shrub
Hardiness: USDA Zones 8 to 11
Gardenias certainly aren't the easiest plants to grow, but one whiff of that amazing floral fragrance is enough to make them worth attempting. These bushy, six- to eight-foot-tall shrubs are well clad in oval to lance-shaped leaves that are deep green and glossy. Richly scented, ivory to white flowers appear mostly in summer; they may be single or double.
How to use them: Where they are hardy, gardenias are useful in shrub borders or as landscape accents. Plant them near a path or next to a deck, patio, swimming pool or other sitting area so you can really appreciate the perfume. Elsewhere, grow them in pots. Enjoy them as houseplants in the winter and set them outside for the warmer months.
Culture: There are as many tricks for growing gardenias as there are gardeners who have tried to grow them. They usually perform best in full sun but may appreciate shade during the hottest part of the day in the warmest parts of their hardiness range. Acidic, humus-rich soil is ideal, and good drainage is a must: Try outdoor gardenias in raised beds, and make sure potted ones don't have water standing in their saucer. A spring dose of fertilizer meant for acid-loving plants can be beneficial. Gardenias also enjoy regular doses of coffee grounds, which provide a slightly acidic mulch. Keep in mind, though, that doing everything "right" doesn't guarantee that your gardenia will thrive. Gardeners in the humid South seem to have the best luck with gardenias planted outdoors where they're basically left alone. Those kept in pots often don't thrive for long, even in the hot and humid climates they prefer. Gardenias are also prone to many pests, including aphids, mealybugs, scale and spider mites; usually, these problems are most serious on plants that are already stressed. Propagate by cuttings in summer.
Special notes: The heady perfume of gardenia blooms inspires gardeners to keep trying to grow these often-temperamental plants. The best advice may be to buy plants in bloom, enjoy them while they last, then discard them when they start to decline.