Azaleas Steal the Show

There is no better time in South Louisiana than March when the azaleas are in full bloom and many yards, gardens and landscapes are abuzz with activity. According to LSU AgCenter Horticulturist Dan Gill, with the introduction and more common use of azaleas that bloom in other seasons, such as the increasingly popular Encore azaleas, it’s not unusual to see azaleas blooming during the late summer, fall and winter. Even so, from now through mid-April is still the time when azaleas show their beauty.

No other shrub in the landscape can beat azaleas for flower power when they are in full bloom. Although the floral display may be relatively short, it ensures the continued popularity of this traditional Southern shrub.

The most common azaleas grown in Louisiana landscapes are Indian azaleas (Rhododendron indicum). A native of Japan, they are characterized by a broad, mounding growth habit. An average mature height is 6 feet x 6 feet, although older, unpruned specimens can easily obtain heights of 10 feet with an equal spread. Flowers of Indian azaleas are usually 2 to 3 1/2 inches across.

Other popular azalea groups recommended for landscape plantings in Louisiana are Glenn Dale hybrids, Carla hybrids, Girard hybrids and Robin Hill hybrids.

Glenn Dale hybrids include several hundred varieties developed as “cold hardy” replacements for Southern Indian varieties. Popular Glenn Dale hybrids include Allure (rosy-pink flowers), Copperman (orange-red flowers) and Fashion (salmon to orange-red flowers).

Carla hybrids were released from an azalea breeding program at North Carolina State University (CAR) and the Louisiana State University Agricultural Center (LA). Popular Carla varieties are Carror (semi-double rose pink flowers) and Sunglow (bright red flowers).

Another azalea group developed for improved cold hardiness is the Girard hybrids. These compact growers produce single or double flowers in shades of white, red, pink and lavender. Popular Girard hybrids are Hot Shot (orange-red flowers), Sandra Ann (purple flowers) and Unsurpassable (red flowers).

Another azalea hybrid group, the Robin Hills, adapt well to the Deep South. They bloom heavily in the fall and also flower in the spring, commonly leading to the name of “re-blooming” or “multi-seasonal” flowering azaleas. Sir Robert is a popular Robin Hill variety. Its flowers range from white to pink. The most popular Robin Hill variety is Watchet. Watchet produces large 3 1/2-inch flowers that are clear pink and ruffled. Plants are compact and spreading. Watchet was a Louisiana Select plant in the fall of 1996.

The Louisiana chapter of the Azalea Society of America lists azalea varieties that will reliably re-bloom in south Louisiana. These plants bloom in the spring and fall. Recommended azaleas for “multi-seasonal” flowering in Louisiana include Watchet, Chinzan, Fashion, Conversation Piece, Abbott, Allure, Arabesk, Hardy Gardenia, Red Slipper, Sandra Ann, Sekidera, Wendy, Janet Rhea, Dorothy Clark and Dorothy Rees.

Azalea Pest

Azalea lace bugs are a leading pest of azaleas and already are active. A small insect, the lace bug attacks azalea foliage, causing it to become stippled with small white dots. The lace bugs live on the underside of the leaves, and the lower surface of the leaves will have dark brown spots. There are several generations of these pests per year, but most damage from lace bugs seems to occur from the early generations in spring. Inspect the healthy new growth of your plants regularly over the next six weeks and treat as soon as you see the first signs of damage. Stop the damage early, because once it occurs, the leaves will not regain their healthy appearance.

Orthene and Malathion are effective in controlling lace bugs. Applications should be directed at the underside of the leaves for best control. Always read, understand, and follow label directions.

Lawn Best Management Practices

Many of you have already mowed your lawn for the first time in 2008. Keep in mind that you should not be thinking about fertilizing your lawn until the first week of April. You may still have brown patches in your St. Augustine lawn from the fall when Large or Brown Patch disease began destroying the leaf blades. If you fertilize too early, you will increase the chance of this fungal disease coming back again! Too much nitrogen fertilizer will increase the chances of this disease coming back again.

The LSU AgCenter has an excellent publication 2940, “Louisiana Lawns Best Management Practices (BMPs) that you need to have to have a more beautiful and environmental friendly lawn. Get your copy now at any Louisiana Cooperative Extension Service office or check out www.lsuagcenter.com for your online copy.

Question of the Week: When should I trim back my liriope ground cover in my landscape?

Answer: The next few weeks is a good time to trim back this groundcover. Liriope, which is a standard plant used to edge landscape beds is almost indestructible in the landscape. Now is the time to cut back the plants to two or three inches from the ground. This will remove the dead or diseased foliage and allow the plant to come back with fresh growth for the spring. After the plants are cut back, you can fertilize with a complete fertilizer in early March according to the manufacturers label.

For more information on these as well as other horticultural topics, call me at 985-446-1316 or email me at bhfletcher@agctr.lsu.edu. You can also check out the LSU AgCenter website at www.lsuagcenter.com.