The gardenia is a genus of more than 200 species of flowering plants in the rubiaceae family, many of which are hybridized varieties. Gardenias' waxy green leaves and fragrant white blooms make them a prized plant. Grown in tropical and subtropical areas as shrubs, gardenia must be grown as houseplants in northern climates.
Gardenia Augusta, known as Cape Jasmine, is the most commonly grown gardenia. Grown outside, it reaches a height of 6 feet or more. Several cultivars have been cultivated for optimum appearance and fragrance. Augusta Beauty produces 2- to 3-inch double flowers and blooms for up to three months. Mystery is more compact and produces semi-double cream or white blooms from mid to early summer. Veitchi, referred to a florist gardenias, are grown in pots in greenhouses for florist and those who seek houseplants. It grows erect and produces pure white double blooms. Gardenia Thunbergia, referred to a Star Gardenia, grows to a height of 10 feet and produces large 4-inch single blooms.
Gardenias originated from the tropical lands of South Asia and Africa. In their natural habitat gardenias grow in leaf litter and humus beneath trees. They derived their name from Alexander Garden a physician in Charleston, South Carolina. Gardenias are often associated with love and romance and were favored by southern women for their fragrant blooms. Its popularity increased rapidly when the gardenia corsage was invented by Rod McClellan in 1937.
Gardenia blooms range from single to double blooms in shades of cream and white. The waxy green foliage makes a striking contrast to these delicate flowers. Gardenia fragrance is heady and sweet, perfuming an entire yard in warm summer evenings. Its appeal comes in part from its fragrant blooms and in part to the striking display of blooms in the moonlight.
Gardenias thrive in zones eight and nine, but are sensitive to cold and must be grown as houseplants or in nurseries throughout most of the United States. Container specimens can be summered outside and returned to the inside when weather cools in late summer or early fall.
All varieties of gardenia are finicky houseplants that require bright southern light that poses a challenge for northern homes. Grow lights must supplement the natural lighting during the winter, set on a timer for 12 hours of sunlight and 12 of darkness. They require distilled water kept a room temperature as they cannot tolerate hard water and cold water will stunt their growth. They require evenly moist soil and will suffer from either over or under watering.