The Texas mountain laurel (Sophora secundiflora) is a desirable landscape shrub popular in the alkaline soils around Interstate 35, which cuts through the middle of the state, and areas westward. The flowers are the most interesting feature of the plant. They appear in the spring and have a distinct sweet smell that some say smells like grape bubble gum. The Texas mountain laurel is often confused with the mountain laurel native to the moist acidic soils of the southeastern United States. Planting and growing a Texas mountain laurel is simple.
Locate an area with alkaline soil. An area with limestone rocks present in the area is ideal because that would be an indication of alkaline soil. A Texas mountain laurel cannot live in acidic soil. Because the small tree grows painfully slow, it would not be a good idea to try and plant in a raised bed with soil treated to raise the pH to an acceptable level. You would have to amend the soil for the life of the tree, which may be 100 years or more.
Dig a hole before purchasing the tree. In very hard alkaline soil that contains limestone that cannot be moved, you must know how big you can make the hole. A hole for a small plant must be as big as a milk jug; for a larger plant, the size of a 5-gallon bucket. You don't want to buy a tree with a large root ball and only be able to dig a small hole.
Buy a Texas mountain laurel at a plant nursery or garden center. Choose a size that can be planted in the hole previously dug in your landsape. Do not attempt to dig a plant up from the wild. Plants taken from the wild rarely do well after transplanting.
Plant the tree and refill the hole with the soil you removed. Mix the planting soil with water as you refill the hole to prevent air pockets from forming around the roots. Do not add mulch or any other soil amendments that may hold water and prevent drainage.The Texas mountain laurel prefers drier, well-drained soil.
Soak the base of the plant deeply if the soil becomes dry just below the surface during the first year after planting. After the first year, little additional water is needed, as the Texas mountain laurel is very drought-tolerant.