How to Care for Outdoor Gardenias

Gardenia flowers produce a strong, sweet fragrance.

Gardenias are flowering evergreen shrubs that are valued for their fragrant flowers and attractive, dark-green foliage that remains all year. Often used as hedges or screens when grown outdoors, gardenias provide privacy and beauty when allowed to reach their full height of up to 8 feet. Hardy in zones 8 through 10, the shrubs thrive outdoors in most southern areas of the United States. In cooler zones, plant gardenias in containers and overwinter them indoors.

Things You'll Need

• Ground bark
• Iron chelate fertilizer
• Pruning shears

Instructions

1. Plant gardenias in a location that receives partial sunlight with dappled shade throughout the day. Choose a site that consists of rich, moisture-retentive soil for optimal growth. Space gardenias 36 to 60 inches apart to allow plenty of room for growth.

2. Apply a 3-inch layer of ground bark to the soil surrounding gardenias to increase moisture retention and slowly release nutrients into the soil throughout the year. Allow about 3 inches between the mulch and the crown of the shrubs to reduce the risk of disease.

3. Water gardenias deeply once every two to three weeks. Apply water directly to the soil to reduce the risk of foliar diseases and mildew. Do not allow standing water to accumulate around the plant's roots, or rotting may occur.

4. Fertilize gardenias twice each year, once during mid-March and again in late June. Use an iron chelate fertilizer to keep the leaves glossy and prevent them from yellowing. Apply according to the directions provided on the package.

5. Prune once each year during late winter to improve the aesthetic appeal and health of the plant. Use pruning shears to trim off any excessively long, leggy, diseased or damaged branches. Remove tall, old stems from the inner portion of the plant to increase air circulation.

Tips & Warnings

• In zones 3 through 7, plant gardenias in large containers filled with well-drained potting soil. Place outdoors throughout the spring and summer months, but bring them indoors when temperatures drop below 60 degrees F. Place in a sunny window and water often enough to keep the soil uniformly moist--about once per week. Place the gardenias back outside and resume regular care when new growth resumes and temperatures rise in spring.

• Gardenias can be grown in full shade, but will not produce as many flowers during the blooming period.

• Iron chelate fertilizer is available at most well-stocked garden centers.

References

• University of Florida Cooperative Extension Service: Gardenia jasminoides
• University of Florida: Gardenias Provide Beauty and Fragrance
• University of Rhode Island Landscape Horticulture Program: Gardenia Care