If you are having difficulty growing plants in Houston, the soil might be the prime suspect. In general, plants need well-drained soil to really thrive. Unfortunately, clay makes up a large part of the soil content in Houston. So what does that mean, and why does it make it harder for some plants to grow and flourish?
Clay in itself is not bad. However, if your soil has too much clay content, then its natural tendencies will work against you. First, clay actually attracts and retains water longer than other soils. If the roots of your plant are staying soggy, then it can eventually kill the plant. Second, clay particles are very small which allows the soil to compact into what can feel like concrete. Plant roots need space to grow and if there isn’t enough looser soil mixed in with the clay, it will prevent your plant’s roots from getting established.
So let’s talk about how to overcome Houston’s clay soils. First, you can choose plants that do well in clay soils such as daylilys, hosta, yucca, black-eyed susans, and aster. Choosing native plants are also a good way to go. Next, you can add equal parts of coarse sand and coarse organic matter to the beds where you plan to plant. It’s important to choose coarse materials so that when it’s mixed with the clay, you end up with larger particles mixed in with the small clay particles. The different size particles create little air spaces that allow water to drain and roots to have room to grow. Some examples of coarse matter include sawdust, potting soil, compost, and large grain sands. Now, mix together the new matter and the original soil with a tiller or garden fork so that it’s well combined.
Another solution is to create a raised bed that you can fill with the exact mix of soils for whatever plants or flowers you are trying to grow. I would recommend this solution for vegetables which also need a balanced pH to grow well. The pH refers to whether your soil is more acidic or alkaline. The pH level directly affects how well your plants absorb nutrients in the soil. By controlling the soil's pH, you can significantly improve plant growth.
If your soil appears be draining, but you are still having problems with your plants, then consider analyzing your soil. My local nursery offers free soil testing at various times of the year. They will check the pH levels as well as the nutrients in the soil and help you find a solution to fix anything that is lacking in your soil.
My early attempts at gardening in Houston had more failures than successes until I learned how to work with the Houston soil and climate and not against it. So I’m hoping that sharing this will help others get to those successes quicker. Good luck!