Using fresh potting soil for your plants is essential to keeping disease and infestation away from the roots and base of your plants. However, when there is an excess of potting soil beyond what you currently need, store it to keep it fresh -- without letting mold or insects get into the mix. Luckily, you can store extra potting soil without much trouble or expense to ensure you have fresh potting soil ready for use when you need it again.
Close the potting soil inside the bag it came in, if possible. Use the resealable zipper-like closure, if the bag has one, or fold the bag over and secure the fold with packing tape or a few clothespins.
Place the bag of potting soil inside a solid, not clear, storage tote -- or pour the loose soil into the tote if the bag isn't available. Close the tote lid tightly over the soil.
Place the tote in a cool, dry area of your home, such as a climate-controlled garage or basement where it will be out of direct sunlight and fluctuations in moisture. Do not store the tote outdoors where day and nighttime extremes can affect the soil.
Check on the potting soil every one to two months to ensure it is not growing mold on the surface, which may appear white, green, brown or black. Use the potting soil within six months after you store it, especially if your variety of soil contains plant food.