ARID PLANTS IN THE BAYOU CITY
Create Your Own Desert Oasis with the Right Plants and Soil Preparation
Story and photos by Linda B. Gay
The subject sounds like an oxymoron, and we know gardeners do love a challenge. The challenge with arid plants in our neck of the woods comes in manipulating the heavy, clay soil so these desert beauties can thrive in high humidity, along with periods of heavy rainfall. You know what everyone says about Houston weather: “Don’t like it, wait a minute and it will change!”
An arid plant naturally occurs in regions where water is scarce both in the air and soil and the soil makeup is rock and sand, which holds no water when it rains because runoff is quick. Plants change their physical look and makeup to adapt to their environment, whether shady and wet to sunny and dry.
ARID PLANTS FEATURES
Some characteristics of arid plants are:
• Small leaves are less than 1 inch (less water loss).
• Leaf color is gray, blue or light green to reflect sunlight and reduce hot temperatures on the leaf surface (cooling).
• Waxy leaf surfaces keep plants from transpiring (moisture loss).
• Hairy and spiny leaf surfaces slow down wind, thus reducing water loss.
• Fleshy taproots allow the plant to penetrate the soil deeper to access pools of water.
So now you see why it is important to amend our heavy soils to grow arid plants successfully in our region. Clay soils are easily amended by using a Mantis tiller to pulverize the clay into small particles. Once you have pulverized the clay, you can amend with limestone (raises the soil pH) or use expanded shale (neutral in pH).
You don’t want to dig out and remove the clay, but just blend the native soil 50-50 with expanded shale or crushed limestone, depending on plant choice and soil type. The shale or rock creates channels in the clay soil that allow water to flow through for rapid drainage, hosts air and gas exchanges and creates pathways for optimum root growth.
LOVE THAT LIMESTONE
Here’s a short list of arid plants that benefit from adding limestone to the soil. You can see lovely examples of these at Peckerwood Garden, and all are available for purchase at The Arbor Gate.
• Cordia boissieri or Wild Texas Olive, with white flowers in the spring and doesn’t produce olives
• Sophora secundiflora or Texas Mountain Laurel, fragrant purple flowers that look like wisteria and smell like grape bubblegum
• Yucca rostrata or Big Bend Tree Yucca, a beautiful architectural plant with white flowers in spring. This yucca could be the poster child for dry garden plantings!
• Nolina texana or Beargrass, a clumping wiry plant that doesn’t exceed
2 feet tall and 2 feet wide and with interesting white blooms. Not a true grass, it is in the lily family.
• Dasylirion texanum or Texas Sotol, a clumping native that grows 4 by 4 feet and produces flower stalks that grow 9 to 15 feet
LOVE THAT EXPANDED SHALE
Here’s another short list of arid plants, with these all thriving by adding shale to the soil. Again, visit Peckerwood Garden for an excellent viewing of these, and all are available for purchase at The Arbor Gate. Use the shale as mulch, too!
• Aloes, tropical succulents best suited in a protected exposure, as they are winter bloomers
• Sedums, several hardy varieties available for sun or shade
• Graptopetalum paraguayense or Ghost Plant, Opal Plant, a true perennial succulent for Houston that forms a rosette
• Hesperaloe parviflora or Red Yucca, a short clumping plant that produces red flowers in early summer. Hummingbirds flock to it.
• Leucophyllum frutescens or Cenizo, Texas Sage is native to South Texas, so grow this one in full sun, not next to the house. Rain triggers the bloom period.
• Scuttelaria suffrutescens or Skullcap is a great perennial for sunny, gravelly soils and flowers 10 months out of the year reaching 6-10 inches tall.
As mentioned, one of the best arid plant collections in the Houston area is found at Peckerwood Garden in Hempstead. John Fairey has been collecting and planting Mexican plants since the early 1970s, and it is very interesting to see how the plants truly adapt because this property is subject to flooding. This botanical collection has more than 3,000 rare and unusual plants from the United States, Mexico and Asia displayed throughout the 20 acres.
Time truly flies when one is immersed in learning about this exquisite plant collection, so thank you, Adam Black, director of horticulture, for sharing your time and knowledge with me.
For more information, check out www.peckerwoodgarden.org …and happy gardening!
Linda Gay is a horticulturist and gardener at The Arbor Gate Nursery in Tomball.