By Susan Albert
If you live in Oklahoma or Texas, you already know your soil type can be a bit challenging. Whether it’s clayey, sandy, or rocky and shallow, here are some ways to optimize your gardening in the South Central region.
- Improve soil by adding amendments.
- Grow plants in raised beds and/or containers.
- In poor soil plant trees and shrubs slightly above grade.
- Incorporate native plants acclimated to the soil type.
Pretty much all soils benefit from adding organic material such as composted manure, peat moss, or compost made from garden waste. Organic matter makes clay soils more workable and improves drainage. If your garden soil is sandy, organic matter helps it retain water. The amendments also add needed nutrients to the soil. Each year add 2 to 4 inches of amendments to the top of the soil and work them in, being careful not to cultivate too close to existing plants.
If the soil is too rocky or clayey, raised beds and containers may be the answer. You can make raised beds out of wood, concrete, bricks, plastic, or stone and size them to fit any space. Height can vary from 8 to 12 inches to grow vegetables, or more for shrubs and perennials. Pictured is a raised bed for shade ornamentals at Har-Ber Village Museum in Grove, Oklahoma.
According to Texas Agrilife Extension, in most parts of Texas it's best to grow vegetables in raised beds, with or without a frame. Mound soil in rows about 8 to 10 inches high and 36 inches apart, if possible, and leveled on top.
Containers are becoming more and more popular for growing vegetables because they are easily controlled environments. Mix the soil for proper drainage and fertility, and locate the pot near a water source and ideal light. You can move the pot easily if needed, especially if it’s on a base with wheels.
When planting a tree in clay soil, do not add amendments but rather site the trunk 1 to 3 inches above grade, according to Oklahoma State University Extension. This aids in getting oxygen to the roots and draining water. Fill in with the native soil. (Amending the soil causes the roots to just encircle within the good soil and not reach out into the native soil.) Be sure to adequately cover any exposed roots above grade with soil and mulch. Pictured is a redbud tree planted slightly above grade in Jo Allyn Lowe Park and Arboretum in Bartlesville, Oklahoma.
If the soil is sandy, plant the tree or shrub even with the soil line.
Another option for dealing with less than ideal soils is invest in native plants that thrive in the area’s soil conditions. For example, easy-to-find plants native to the Texas/Oklahoma region include coneflowers, black-eyed Susan, amsonia, butterfly weed, mealy blue sage, Mexican bush sage, Russian sage, liatris, and larkspur.
Native shrubs and trees include American beautyberry, buttonbush, red buckeye, Texas indigo bush, spice bush, bald cypress, bur oak, smoke tree, Carolina buckthorn, Mexican plum, and roughleaf dogwood. Pictured is a smoke tree at the Linnaeus Teaching Gardens in Tulsa, Oklahoma.
Three vines indigenous to the South Central region are coral honeysuckle, passionflower, and cross vine, all attractive to hummingbirds.
So you may not have the perfect soil now, but continually adding compost over time should improve the structure of the soil. Until then, raised beds, containers, and native plants should do the trick.