Once again, Tyler’s Azalea and Spring Flower Trail will be drawing thousands of admirers to view the spectacular displays of azaleas, along with dogwoods, redbuds and other spring blooming plants. I bet this has many of you thinking about adding some of these wonderful plants to your own landscape.
Nurseries are stocked with azaleas, and early spring is a great time to plant. Azaleas are not difficult to grow in East Texas, and you can have your own little bit of azalea trail right at home by carefully following some simple guidelines.
Location. Many people think that azaleas prefer shade, and they do appreciate protection from intense sunlight. But azaleas planted in deep shade will bloom very poorly and also be weak growers. Morning sun or very bright, filtered sunlight provide the best conditions for abundant blooms. The more direct sun they receive, the better they will bloom.
Avoid locations such as next to a western or southern brick wall unprotected by trees, or in sunny beds surrounded by concrete or asphalt. The reflected heat will increase the stress on the plants, making them more prone to wilting, azalea lace bugs and stress-related diseases.
Get the soil ready. Azaleas have a very fine, shallow root system, and need a very well-drained soil. But, they also prefer soils that stay evenly moist. So you have to do a balancing act. While sandy soils provide great drainage, they dry out very quickly. Clay soils, on the other hand, are poorly drained, holding water for long periods of time and have less air around the roots. Poorly drained soils will rot roots and kill azaleas.
Both types of soils should be amended with large amounts of very well-decomposed organic matter. Finished compost or aged, finely shredded pine bark make excellent additives to both clay and sandy soils. Peat moss can also be used in sandy soils, in combination with other organic amendments. Organic matter increases the water-holding capacity of sands, while opening pore spaces in tight clay soils.
Break up the soil up to 12 to 18 inches deep. Incorporate organic matter throughout the entire bed rather than making individual planting holes. Design the bed to be large enough to handle the ultimate size of the mature plants. Tags on the plants, or azalea variety lists will indicate mature plant width for each variety.
If your soil is sticky, heavy clay, the best option is to create a raised bed. Break up the soil first, and then incorporate a mix of top soil and organic matter, raising the bed several inches. Expanded shale is a product that many have found beneficial for incorporating into clay soils along with organic matter to develop aggregates that improve aeration and drainage.
It is not recommended to add fertilizer at this time. Most of our East Texas soils are naturally acidic, which is what azaleas require. A soil test can confirm the pH or acidity of your soil.
Planting. Proper planting is a critical step in growing healthy azaleas. Azaleas grown in containers are frequently root-bound, and certain steps should be taken to insure good root growth.
First, soak the pots in a bucket of water, making sure the entire soil mass is completely watered. If bubbles come out the top of the root ball, keep soaking until the bubbling stops.
Next, pull the plants out of the pots. If you see a solid mat of roots on the outside of the soil ball (and often this will be the case), make several slits with a sharp knife about ﾽ inch deep, starting at the top and slitting down the side. I like to further tease out matted roots with a hand cultivator to increase the contact of roots with the soil in the bed. Be sure to cut any larger roots that are encircling the root ball.
The soil in the planting bed should be settled before planting your azaleas. Dig the hole no deeper than the root ball, and backfill with the prepared bed soil. If the soil in the bed has a high clay content and is somewhat poorly drained, plant your azaleas high, and bring soil up to cover the top of the soil ball. Never plant azaleas deeper than the original soil ball, or bring soil up over the stem and branches.
Thoroughly water the soil to settle it around the plants, and inspect them afterwards to see if any root balls became exposed. If this is the case, add more soil and rewater.
Mulching. A mandatory step is to apply a layer of mulch over the surface of the soil and under the azalea plants, but keep it off of the stems. Mulch helps maintain a better root environment, keeping the soil more evenly moist by reducing evaporation, and keeping ugly weeds from competing with your new plants. As organic mulches decompose, they add more organic matter and trace amounts of nutrients beneficial to azaleas. Replenish the mulch at least once a year. Pine needles make an excellent mulching material, as do bark products, and shredded leaves (do not use large, unshredded leaves).
Watering. Azaleas roots are very shallow and subject to drying more than many other types of shrubs. Water them regularly during hot, dry weather, and do not let them get to the point of wilting. On the other hand, avoid light sprinkling every day. Be sure the water penetrates several inches deep throughout the root zone. And, do not keep the soil soaking wet, as this will rot roots and lead to death.
Fertilizing. Azaleas need very little fertilizer, and the fine root system is sensitive to the salinity in fertilizers. Good soil preparation with adequate amounts of quality compost, along with an organic surface mulch, will provide most of what azaleas need.
If growth is particularly poor, and other cultural problems such as inadequate watering or poor drainage have been ruled out, then consider applying a fertilizer. The safest method is to purchase products designed for use on acid-loving plants and follow application rates on the package. Azaleas are typically fertilized right after they have finished blooming, and never in mid-summer during drought stress, or in late fall when a new flush of growth could be damaged by cold weather.
Scatter the fertilizer out evenly over the surface of the soil, preferably using a hand-type crank spreader. Never place clumps or a handful of fertilizer around the base of the plants. Follow up with a good irrigation.
Keith Hansen is Smith County horticulturist with the Texas A&M AgriLife Extension Service. His web page is http://EastTexasGarden ing.tamu.edu. His blog is http://agrilife.org/etg.