Dirt vs Soil

Let's talk dirt!

Dirt is dead - it's not at all what you want to grow your plants in. Don't misunderstand, I'm not promoting commercial potting mixes or bagged soil you purchase in garden centers. You can certainly use natural "dirt" from the ground or what you have on hand (even old, dry, used potting mix left and forgotten from previous seasons). However, the difference between dirt and soil: life. 

Dirt is dead, devoid of all beneficial organisms (both macro and micro). There is no life in dirt, rendering it useless as a growing medium for your plants. Soil, on the other hand, is filled with beneficial organisms. This may include worms, earwigs, rolly polies, centipedes, fungus, springtails, and many more macroorganisms, or this may include microorganisms such as mycorrhizal fungi and nitrogen-fixing bacteria. 

How can I tell if I have dirt or soil in my garden/planter?
If you look closely at your medium and dig a little bit, you may find some beetles, earwigs, or other soil creatures if you're working with soil. If you notice your medium is dry, hard, caked, or otherwise devoid of moisture, it's likely dirt at this point and cannot support life - including your beloved plant. 

How can I use dirt if it's useless to support life?
    If what you're working with is dirt (dry, devoid of life), there's still hope! You don't have to toss it and purchase new soil from a garden center (though, you can certainly purchase more soil and/or compost if you don't have enough already). 
    You can bring life back in to the old dirt you have on hand, starting with rehydrating the medium. Oftentimes, it's difficult to rehydrate old potting mix, since it's often made with peat (learn why conscientious gardeners are avoiding peat products, coming soon), which is great at holding on to moisture when it remains damp, but when it dries out, it's very difficult to rehydrate without a good, thorough mixing and soaking. 
    Once you've rehydrated your dirt, you can start adding amendments to it, such as compost, vermicompost (worm castings), manure, leaf mold, bio-char, coconut coir, gypsum, vermiculite, perlite, lime, sulfur, or potash, among others. (We'll go into more detail about all these soil amendments in another article.) Depending on your plant's needs will determine which amendments you want to mix in, however for all plants, compost and vermicompost are always good options. Depending on if your plant needs a lot of nutrients or prefers a more nutrient-deprived medium will determine how much compost and other nutrient-rich components you want to add. 
    Using compost or vermicompost are great options to inoculate your dirt with beneficial microorganisms (and possibly macroorganisms) as well. By transferring and mixing in healthy compost, you're introducing all the organisms that have been breaking down the organic matter into your newly-revitalized medium and creating a living environment in which your plants can thrive. The compost also does a great job of slowly releasing nutrients to your plants over time. You may want to add some organic fertilizers, such as blood meal, bone meal, or kelp meal, to your medium as well (more about these and other organic fertilizers) to encourage healthy plant growth.

And voila! You just recycled/repurposed/revitalized (whatever term you want to throw in there) your dead dirt into living, life-giving soil, saving you money and waste, and allowing you to grow new plants in your newly-restored soil medium.

If you don't want to revitalize your old potting mix, don't throw it in the trash (unless you had pests or diseases infiltrate it). If it was just used and dry with no concerns about harmful organisms, go ahead and compost it - it'll get processed by the organisms in your compost heap and be ready to feed your plants next season.