Buy a premixed vermiculite soil or use a one-to-three or half-and-half ratio with potting soil. “For those plants that need to be in damp soil, vermiculite will be effective,” says Funk.

While vermiculite can be an important and helpful soil amendment, it isn’t perfect. When deciding if you’d like to add vermiculite to your mix, consider the following.

Like with soil in the garden, it will improve your house plants' soil aeration, too. Where to buy vermiculite Vermiculite is available for sale in bags from garden centers and online.