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Tuesday - June 09, 2009

From: Austin, TX
Region: Southwest
Topic: Soils, Watering, Shrubs
Title: How will my Texas Mountain Laurel survive clay soil?
Answered by: Jimmy Mills and Joe Marcus


Mr. Smarty Pants: I live in a new neighborhood (brownfield site) in Central Austin where the developers have put fill in the yards. After not much more than 2 inches of topsoil you encounter fairly plastic clay ..much like you see along the 35 corridor near Waco. They've planted a several gallon size mountain laurel. Is the clay soil is going to be a problem? If so, is there something I can to to augment the soil? The leaves are light green, not the dark glossy green I see on more established laurels. Thanks much.


Sophora secundiflora (Texas mountain-laurel)  is a hardy shrub/tree whose habitat includes brushy slopes and open plains, and is common in limestone soils in the western and southern parts of the Edwards Plateau. It prefers well drained sand, loam, clay, caliche, limestone. The key here is well drained.

The problem with the clay soil could be the drainage. The clay around your Texas Mountain Laurel is also acting as a "clay pot " which will restrict the root growth and cause the plant to become root bound after a while.

There are two courses of action to follow, and you can do one , or both. The second best action is to expand the size of the hole the tree is planted in and substantially increase the volume of well-drained soil around the tree. The best thing to do is to replant the Sophora, but plant it on mounded soil 4-6" above the grade of the garden, again using well-drained soil. I'd do both.  Also I would wait until late fall to do the transplanting. In the mean time, water carefully so you won't drown your plant.




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