By Kat Yares, Garden Guides Contributor
Gardenias (Gardenia jasminoides) are one of the most exotic plants growing in the United States today. Imported from southern China, the plant is also known as Cape Jasmine. Best known for their snowy white flowers and their jasmine-like fragrance, the evergreen shrub is a favorite in southern states. Gardenias thrive in heat and humidity and are not suited to growing in northern climates above the USDA Zone 7.
Gardenias grow from 2 to 8 feet in height and bloom beginning in mid-spring and into late summer. The plant, with its dark green, glossy leaves will shape itself into a rounded shrub, perfect for planting outside windows so their fragrance can be enjoyed both indoors and out, simply by opening a window.
Gardenias prefer full sun, although light shading is acceptable. The soil should be rich in nutrients and acidic with a pH somewhere between 5.0 and 6.0. Gardenias do best in areas that can be kept moist but drain well.
Gardenias are year-round evergreens. Gardenia's love heat and high-humidity. Reddish orange berries on long stems replace the flowers on a gardenia plant.
Choosing a Variety
Gardenias come in varieties suited for almost any landscaping purpose. Dwarf varieties have been developed as well as Bonsai Gardenias for indoors or container plants.
Use litmus paper to determine the pH of the soil in the chosen area. Sulfur can be added to the soil to lower the pH level if necessary. Dig a hole twice the size of the root ball and then add an acid fertilizer if needed to raise the pH levels to 5.0 to 6.0. Mix the fertilizer with peat or potting soil and spread in the bottom of the hole. Center the gardenia plant and begin filling the hole with soil. Water thoroughly after planting to remove any air pockets that may have formed around the root.
Gardenias need 2 things to thrive: moisture and fertilizer. Water the gardenia plant at least once a week and maintain at least 3 to 4 inches of mulch around the trunk to retain moisture for the plant. Gardenias should be fertilized monthly during the blooming season with a good acid-base fertilizer.
Control the shape of the gardenia plant by pruning in early spring before the flowers begin to bud. Deadheading, or pulling off, the spent flowers will encourage more blooms. Use an insecticide soap to control white flies, aphids, spider mites and mealy bugs.