How to Grow Healthy Azaleas

White Azaleas image by Marci Degman

Overview

Azaleas are not difficult to grow, but they do have specific needs. They are in the same family as the rhododendron but are much more versatile. There are azalea hybrids developed for warmer regions where rhododendrons will not grow. You can plant both evergreen and deciduous azaleas. The evergreens tend to be denser plants, and the deciduous azaleas are more open with larger flowers. Some of the most popular deciduous azaleas are the Exbury hybrids, which have larger flowers in brilliant yellow, orange and red tones. The evergreens do better as edging or filler plants.

Step 1

Choose the proper site for your azalea. Most azaleas prefer part shade and will do well underneath conifer trees. The rare few that can handle full sun will say so on the label. An azalea that receives some morning or filtered sun will bloom the best.

Step 2

Amend your soil if it is alkaline. Soil pH is critical for azaleas. They must have acidic soil. Acid-based fertilizers and conifer needles will help. In alkaline soil, azaleas cannot take in nutrients and become yellow or chlorotic.

Step 3

Choose the azalea that best suits your situation. Azaleas can range from 1 to 6 feet tall. Know how large the azalea will get when it is mature. A common mistake is to plant a larger variety and then try to keep it small. This will result in few or no flowers and an odd-looking plant.

Step 4

Dig a hole just slightly larger than the root ball. Take the spade and break up the soil at the bottom of the planting hole. Incorporate nutritious compost in with the existing soil before planting. If you choose not to use compost, you will need to incorporate fertilizer into the soil. Use a fertilizer that lists rhododendrons and azaleas on the label. Fall is the best time to plant azaleas.

Step 5

Water the azalea thoroughly right after planting. To be healthy, azaleas will need regular water throughout their lifespan. They are not drought-tolerant plants.

Step 6

Add 2 inches of garden mulch around the base of the azalea. This will help the soil retain moisture. You can use any compost or even conifer needles and cones. Add more mulch every spring. Do not allow mulch to pile up around the trunk, as this can encourage disease and insect problems.

Tips and Warnings

  • Other materials can contribute to alkaline soil pH. Avoid planting azaleas near turf areas if you apply lime, as this will run off into the beds and increase the pH. New concrete will leach out alkaline substances, so avoid planting azaleas next to new driveways, sidewalks and foundations.

Things You'll Need

  • Azalea plant
  • Shovel
  • Compost
  • Garden hose
  • Fertilizer
  • Mulch

References

  • Sunset Western Garden Books; Sunset Books; 2007
Keywords: rhododendron, azalea, acid loving plants, shade plants, filler shrubs

About this Author

Marci Degman has been a landscape designer and horticulture writer since 1997. She has an Associate of Applied Science in landscape technology and landscape design from Portland Community College. Degman writes a newspaper column for the "Hillsboro Argus" and radio tips for KUIK. Her teaching experience for Portland Community College has set the pace for her to write online instructional articles.

Photo by: Marci Degman