Don't Throw Out Your Old Potting Soil In The Fall Without Knowing This

Potting soil can be tricky to manage — especially considering how expensive it is to replace, and how much time it takes to learn how to make it. As such, when it comes to the end of the growing season, you might be left wondering what you should do with it. And while many people might just throw their old potting soil away, it can actually be reused under the right conditions.

If the plants in your potting soil were doing well this past year, and they didn't seem to suffer from disease or infestation, you're probably fine to reuse the soil. Since the previous plants used much of the nutrients in it, however, you will need to add fertilizer — preferably a slow-release variety to work through the more compact used soil. If you made sure to store extra potting soil when you last purchased it, you can mix it in with the used soil; simply replace the top 6 inches of old soil with new. By replacing the top layer, you'll make sure a plant's roots have space to grow before they reach the old soil beneath.

If your potting soil didn't perform as well this past season, you can still reuse it. To rid the soil of any leftover microbes, though, you'll need to sterilize it first. There are several ways to accomplish this, but the most winter-friendly option is to bake it in an oven. Lay your soil in a pan, making sure it's no deeper than 4 inches, then cover it with foil. Bake for 30 minutes at 180 degrees Fahrenheit, then remove it and allow it to cool while covered. It's important to not let the soil reach above 200 degrees Fahrenheit, as this will produce toxins.

Once your soil is sterilized, you'll need to boost the nutrients contained in it. Mix the old soil with some new potting soil, then add a slow-release fertilizer. If you're doing this before planting season arrives, make sure you know how to store extra potting soil to keep it fresh and ready. And of course, if you don't really feel like going through all this trouble, you can just change your potting soil altogether. That said, you can still put your old soil to good use by applying it as a topdressing for other plants in your garden, or using it to fill holes in your yard.