The Time to Plant Azaleas & Gardenias

Azalea Facts

• In addition to holiday gift plants, azaleas grow as larger evergreen or deciduous shrubs -- evergreen varieties typically grow in milder plant hardiness zones. “Delaware Valley White,” a broadleaf evergreen variety, hardy from U.S. Department of Agriculture plant hardiness zone 6 through 8, grows up to 4 feet tall and wide. The deciduous pinxterbloom azalea (R. periclymenoides), hardy from USDA zone 4 through zone 9, grows to 6 feet tall and 7 feet wide. Azaleas bloom in shades of white, red, pink, purple, orange, and rarely, yellow.

Azalea Planting Time

• Azaleas bloom from April through May and begin forming new buds as summer begins. Pruning and planting are stressful activities for any plant -- and summer heat is no time to expose tender roots. Potted azaleas withstand planting in either early spring or early fall as long as their roots can find purchase and resume their growth before cold weather, another stressor. Transplants and bareroot shrubs require planting as soon as the weather and soil warm in very early spring -- from February through early April, depending on the garden’s hardiness zone -- so they are well established before summer heat sets in.

Gardenia Facts

• Gardenias, hardy from USDA zone 8 through zone 11, bloom on evergreen shrubs that grow 3 to 8 feet tall and up to 8 feet wide, depending on variety. The white flowers, formed similar to roses, bloom from May through the summer, contrasting with the plant's shiny, dark green leaves and delivery the lovely fragrance they are so famous for. Some bloom into fall. Like woods-dwelling azaleas, gardenias prefer part shade and acidic, well-drained soil. Grown indoors, gardenias require bright light and high humidity. Consider this lovely shrub a prima donna because of its fine, shallow roots, inability to set flower buds below 60 degrees Fahrenheit and susceptibility to several fungus diseases.

Gardenia Planting Time

• Gardenia’s tender roots require moisture, so attempting to plant gardenias in the heat of summer or in winter while they set buds sets the plant back. Plant them instead in autumn or early spring. In late summer, prune them as soon as their flowers fade to encourage increased bud-set. In spring, plant gardenias early enough to allow eight weeks or more before summer heat sets in.