Betty Montgomery: Choosing the right azaleas for your garden

Azaleas light up gardens in spring with a profusion of colors. They are easy to grow, come in a wide range of colors and if you choose your varieties carefully, you can have blooms from late February to May and even into summer. Plus, they come in all shapes and sizes, ranging from dwarf plants to ones that grow to about 12 feet.

According to the Azalea Society of America, there are more than 10,000 varieties of azaleas that have been registered plus, there are others that have been grown from seed that are not named varieties. Azaleas are technically a member of rhododendrons family but I still refer to them as azaleas.

Azaleas fall into two general categories: evergreen and deciduous. The evergreen ones are the most common and are what I have chosen to be the backbone of my garden. These are native to Asia, mainly Japan and China. The deciduous azaleas, which are native to North America, are lesser-known and harder to find. These shrubs are magical when in bloom and I hope I am never without some of them in my garden.

Most of the azaleas in my garden are evergreen. I have chosen them because I wanted shrubs that would make the garden look pretty all four seasons of the year and having evergreen leaves makes this possible. They are the staple of my garden, especially in the winter months when many trees do not have leaves and these lovely plants give the garden some greenery. I also plant them because they come in a plethora of colors: white, pink, red, lavender, violet, salmon and orange. There are also some that are striped and others are two toned.

The largest of the evergreen azaleas are the Southern Indicas which can grow up to 12 feet if left unpruned. These are the ones that are grown the most in the South. If you watch the Masters Tournament, you will see them flowering. There, they grow "George Tabor" (light pink), "GG Gerbing" (white), "Formosa" (purple) and "Judge Solomon" (coral-pink). This classification of azaleas I have found to be the hardiest, taking shade and sun.

The smallest ones that I grow are the Gumpo azaleas, which grow to a height of 1- to 2-feet tall and are usually found in white, pink, purple and red. These are widely grown in Japan, but are not grown as much in the United States. They bloom a good month or two after other evergreen azaleas and bloom after the new growth has emerged. The flowers are hidden in the foliage and not quite as showy as some of the other varieties. Today, you can also find evergreen azaleas that re-bloom. Encore and Bloom-a-Thon are two that are repeat bloomers.

Deciduous azaleas are an outstanding plant that are native to the United States and grow naturally in the woods where I live. When exploring the South in 1791, William Bartram discovered the bright blooms of the native azalea, also called flame azalea. When describing the plant he said it was, “certainly the most gay and brilliant flowering shrub yet known.” This is truly a magnificent plant, blooming in vibrant red, orange, yellow and gold flowers or a mixture of these colors. Some are quite fragrant and will perfume a garden.

Azaleas require very little pruning. Remove the long stray shoots, but also cut some branches down inside of the plant to allow sunlight and air movement to get into the center of the shrub. Be sure to do this immediately after they bloom because they set buds for the next year soon after they bloom. If you cut later in the summer, you could cut off the buds that already have been formed.

When it comes to fertilizing azaleas, it is best to do this after they bloom. If you fertilize them before they bloom you will get more foliage than blooms and if you fertilize them in the fall, it will encourage new growth that might not “harden off” before frost comes calling. I fertilize azaleas with a mix I make up. It consists of one 40-pound bag of cow manure, one 40-pound bag of cottonseed meal and a quart of Epsom salt. I put a cup on the smaller plants and two cups on the very large shrubs. You can buy fertilizer that is specific for azaleas and is an excellent product. Azaleas have shallow roots and can burn easily with commercial fertilizer if you are not careful.

Locating azaleas is also very important. In general, evergreen azaleas do best in dappled light with perfect drainage however, I have found that Indica azaleas will take more sun than many other varieties. Azaleas are best grown in acidic, organically rich soil that is well drained. They also like areas that give them morning sun with afternoon shade. Poor drainage inevitably leads to root rot, therefore raised beds or an area with a slope is ideal for planting. This is especially true in areas with heavy clay soils. They will also benefit greatly from a mulch to help retain moisture and stabilize soil temperatures. Now to acidify soils as needed (plants generally like soil pH in the range of 5.0 to 5.5), add sulfur or iron sulfate to soils to lower the pH, lime takes the number up so I do not recommend lime.

There are many different azaleas that are not grown in abundance and you have to seek them out. If you do not have a deciduous azalea, you might consider planting one. "My Mary" is my favorite. Visit a garden center that specializes in different azaleas and see what is available. Unique azaleas are well worth seeking them out.

Betty Montgomery is a master gardener and author of “Hydrangeas: How To Grow, Cultivate & Enjoy,” and “A Four-Season Southern Garden.” She can be reached at bmontgomery40@gmail.com.