Raised Beds: Best Practices for Soil, Liners, and Planting Depth

When you build a raised bed, an elevated garden structure filled with soil, designed to improve growing conditions and reduce bending. Also known as elevated garden beds, they’re one of the smartest moves for home gardeners who want more control over their soil, fewer weeds, and better drainage. Whether you’re growing tomatoes, cucumbers, or herbs, the success of your raised bed doesn’t just come from what you plant—it comes from how you build and maintain it.

One big question is whether you need a garden bed liner, a barrier placed at the bottom or sides of a raised bed to control weeds, pests, and soil loss. Also known as landscape fabric, it can help—but not all materials are equal. Plastic might keep out weeds, but it can trap moisture and suffocate soil life. Landscape fabric lets water through and still blocks roots, making it a better choice for most gardens. Then there’s the sides: lining them can stop rot and keep soil from washing out, especially if you’re using wood. But if you’re using stone or metal, you might not need it at all. Another key factor is soil depth, how much vertical space your plants’ roots have to grow. Tomatoes need at least 12 inches, but cucumbers can get by with 8—unless they’re vining types, which crave 18 inches or more. Get this wrong, and your plants struggle even if the soil is perfect. And what’s in that soil? Peat moss gets talked about a lot, but it’s not great for the planet and doesn’t last long. Most gardeners who stick with raised beds long-term switch to compost, leaf mold, or coconut coir—things that feed the soil instead of just filling space.

You don’t need to replace the soil every year. Most raised beds only need a top-up of compost or aged manure every 12 to 18 months. The real problem isn’t old soil—it’s compaction, nutrient loss, or hidden pests. Check your soil texture, look for earthworms, and test drainage by pouring water on it. If it pools, you’ve got a problem. If it drains fast and the roots are white and healthy, you’re doing fine. The best raised beds aren’t the fanciest—they’re the ones you understand well enough to tweak without guessing.

What you’ll find below are real answers from gardeners who’ve tried it all: plastic vs. fabric, peat moss vs. compost, 6 inches vs. 18 inches deep. No theory. No hype. Just what works—and what doesn’t—when you’re trying to grow food, save time, and keep your garden healthy year after year.