Whether you're building a sandbox for the kids, adding topsoil to your sandy yard or using sand simply for its ornamental value, you need to keep it contained in the garden or area. If too much sand mingles with soil, you can destroy its quality, whereas soil in your sand will diminish its decorative or play value. You can use landscape fabric as an effective barrier and save time and money.
Landscape fabric is a barrier that can be used for a variety of purposes, but generally speaking its intent is to create a sharp divide between the soil below it and whatever material you put down above it. If you want a purely sandy environment, such as a sandbox, you may wish to lay down plastic, which doesn't allow anything through the barrier. If you want movement of water and oxygen -- for instance when laying fabric on top of soil in which plants are growing, and then placing sand on top as a decorative element -- you should use a fine-meshed woven fabric.
Letting Sand Through
Theoretically, landscape fabric, especially the very fine-meshed type, ought to be impermeable even to very small-grained materials like sand. However, landscape fabric is susceptible to rips and tears that can let material of much larger sizes through. Similarly, if landscape material is not well anchored to the ground, sand from underneath the fabric may escape, or sandy mulch from on top of the fabric may trickle down into the soil. When using sand in the garden, it may not be the best idea to place it too close to the bases of plants emerging from landscape fabric, because it could also enter the soil that way.
Before laying landscape fabric down, prepare your site by removing all large rocks, trees, branches, brambles and other objects that could create rips or tears in the fabric. Smooth the ground to create a flat surface to lay the material on, and then use pins to anchor it to the soil firmly. To plant after you lay the fabric, cut an X in the material to make a planting hole for your plants. Position them in the ground, and then fold the material back toward the plants. If you are creating a sandbox and using plastic, extend the plastic beyond the edges of your box's frame to avoid letting sand into the soil.
Before putting down landscape fabric, assess what you need to use it for. If you're trying to keep weeds out of a planting bed that you may wish to update at some point, laying down a bunch of sandy mulch or gravel may not be the best choice. It will be hard to remove and, when transferred to other areas of the garden, can diminish the quality of your soil. Although plastic sheeting may seem similar to landscape fabric, don’t use it as a permanent addition to a growing landscape because it restricts the flow of air and water.