Dry, hot regions are difficult places to grow plants because the soil dries out quickly. As a result, farmers in arid and semi-arid regions irrigate their fields with buried networks of irrigation tubing and cover the ground with plastic sheets. But plastic sheets are expensive and create waste. Now, researchers reporting in ACS Agricultural Science & Technology have developed a simple, biodegradable ground cover—wax-coated sand—which keeps soil wet and increases crop yields.