With clouds of pink or white spring flowers clustering against vibrant green foliage, potted azaleas are a popular Mother's Day and Easter gift, but after a while they outgrow their pots. Rather than repot, consider moving them outdoors. A member of the rhododendron family, azaleas are very happy outdoors, under the right conditions. Groups of them burst into a lovely spring show every year and provide an architectural element to the garden for the rest of the year.

Blooming pink azaleas
credit: Thinkstock/Comstock/Getty Images

Azaleas Need Space

Before planting azaleas outdoors, remember that the cute little potted plant is going to grow much taller, and azaleas also have a spreading habit. It is normal for a mature azalea to reach 4 feet wide and high. Also, they can live for decades, and have been known to grow as large as a small tree. So allow enough space from side to side and front to back. Azaleas also like a little light shade.

Loosen the Root Ball

Azaleas are normally sold in pots. As a result, they can become root bound, especially if you've kept them in the original pot. To plant them outdoors, pull the bottom of the root ball loose. This may mean trimming some of it away with a knife. Don't worry about hurting it; you're helping it. To loosen a tightly bound plant in a plastic pot, you can roll it on the ground and press down on the side with your foot.

Size of the Hole

The hole for an azalea should be twice as wide as the root ball, but only one and a half times deeper than the root ball. They have a shallow root system, so a deeper back-filled hole is not necessary. Remember to allow a few feet between the plant and the house or fence, if that's where you are planting it.

Soil Acidity Matters

Azaleas love acidic soil with a pH of 4.5 to 5.5. You can take a sample of your soil and have it tested at a lab or buy a soil testing kit at a garden center. If your soil is too sweet, or alkaline, you can amend it with leaf mold, peat moss or pine wood chips.

Keep Your Azalea Watered

Water your azalea every day for the first week of its life in the ground. Use enough to moisten the ground without flooding it. After that, water once a week until it's well established.

When to Prune

Prune your azalea after it's done flowering. Pruning will help to keep it nicely shaped, keep the growth in check and help it to produce flowers more abundantly.