How to Grow Azaleas

Azaleas are easy-care flowering shrubs that reward gardeners with massive blooms. Learn how to grow these quintessential Southern plants.

What we think of as the quintessential southern plant, the azalea, is actually mostly native to Asia. There are a few native to the United States, but the plants with huge flowers in pink, white, red, burgundy, and coral are imports. No matter! They’re a must-have in zones 6 to 9 for their amazing spring show. As shrubs go, azaleas are of the "little work, big reward" variety, so they’re definitely worth considering for your own garden and landscape.

Here’s how to grow azaleas.

How to Choose Azaleas

There are thousands of azalea varieties?too many to list. The best way to select the right one for your garden is to consider the area you have available. If you have a small space garden, look for a dwarf or smaller type. If you have lots of space to fill, some of the older Formosa varieties are great choices. Several companies offer re-blooming varieties, which bloom multiple times during the year. Some of these can get quite big, so do your research before buying.

Where to Plant Azaleas

Select a location that has morning sun and afternoon shade, or filtered light. Hot all-day sun can stress the plants and make them more susceptible to pests. Azaleas also require well-drained, acidic soil. Ideally, you would want to test the soil pH using a soil testing kit. If the pH is higher than 6.0, lower it by applying aluminum sulfate to the soil according to package instructions.

How to Plant Azaleas

When planting azaleas, spacing depends on the variety you’re growing. Larger bushes require more space than smaller types. It’s tempting to plant small bushes close together, but you will end up chopping down every other azalea bush if you do that. Read the plant tag to determine correct spacing, then follow these steps:

Set plants where you plan to plant.
Dig a planting hole that is twice as wide and just as deep as the root ball of the plant.
Remove the plant from its container and place it in the planting hole so the top of the root ball is even with the soil line.
Fill in around the plant with the soil you removed mixed in a 50:50 ratio with Miracle-Gro® Garden Soil for Trees & Shrubs. This will give the plants instant nutrition and help them grow strong roots.
Water thoroughly.
Spread a layer of mulch around the plant’s roots, taking care not to mound it against the plant. This will help keep the soil moist.

How to Water Azaleas

Thoroughly soak the soil two to three times per week during the first two months after planting. You can gradually decrease the frequency of watering as the plants become rooted. After three or four months, watering deeply once per week should be sufficient. After the first growing season, plants should not need supplemental water unless it hasn’t rained for two or more weeks.

How to Feed Azaleas

A month after planting, begin feeding azaleas with Miracle-Gro® Water Soluble Azalea, Camellia, Rhododendron Plant Food. In addition to the main plant nutrients, this fertilizer also includes micronutrients such as iron, manganese, and zinc, which are vital for growing azaleas (and other acidic soil-loving plants). Be sure to follow label directions.

How to Prune Azaleas to Control Size and Shape

If you selected azalea types that are good fits for the place they’re growing, you shouldn’t have to prune azaleas hard every year. The best time to prune azaleas is in the spring, right after they bloom.

Start by using hand pruners or loppers to remove any branches that stick out significantly from the rest of the bush. Cut those back to a main branch. Then, decide whether you need to shorten the shrub. To significantly reduce size, cut branches back to a whorl (circle) of leaves farther down on the bush. Always make sure to prune so the bottom of the bush is slightly wider than the top, so sunlight can reach all the leaves.

How to Prune Azaleas to Renew Growth

Old, overgrown azaleas, or azaleas with an empty center, can be rejuvenated with a harsh trim. Renewal pruning is done in the late winter or early spring, before flowering. (You’ll have to go a year without flowers when you do this.)

Cut plants back to 12 inches above the ground. When the plants begin to re-grow, prune the ends of the new growth back by 6 inches to encourage branching. Always keep the soil evenly moist and feed regularly with Miracle-Gro® Water Soluble Azalea, Camellia, Rhododendron Plant Food after renewal pruning. It takes a lot out of the plants to re-grow, and the food will give them a boost.