Another use for perlite? It is very versatile. Besides making a better soil mix for your garden, perlite saves water. By spreading it lightly on top of the soil when it is hot it conserves water. Not only that but it also reflects sunlight instead of the dark brown raised bed soil surface. Why is that important? Tied to saving water, the reflected sunlight keeps the soil about 4 to 5 degrees cooler. Reflected light controls pests. Pests are not only insects but also weeds. Perlite mulch does both; it reflects sunlight to the underside of leaves where insects like squash bugs and aphids like to hang out and suck plant juices. Hanging out on the underside of leaves avoids predators like birds and stays out of the direct sprays of pesticides like Neem oil and soap and water.

Reflecting the sunlight on the bottom side of plant leaves speed up plant growth. Normally the underside of plant leaves is in the shade. Not with a perlite mulch! And lastly, when you are entering the cooler part of the growing season or you are replanting warm season vegetables with cool season vegetables in late summer and fall, mixing this perlite into the soil makes it even better! Perlite improves drainage and soil texture and structure.

Use about one third of a 4 cubic foot bag of perlite when it is applied as a mulch to a 4’x8′ raised bed. That’s about $4 for an application of mulch …. that saves water, repels bugs, increases plant growth and improves the soil when you replant!!