One of the key ingredients for success in growing container plants is a quality potting mix. Even after several years being in a pot, old potting mix can still be recycled and rejuvenated if it is not riddled with disease or insect pests. Using the old mix as a foundation, organic matter can be added to bring new nutrients, texture and use to the soil concoction. Just avoid using topsoil as one of the additives to the old potting soil mix.
Things You'll Need
- Compost, moist peat, or well-cured manure
- Wheelbarrow or plastic bin
Empty your old planting pots into a wheelbarrow or large plastic bin.
Crush the soil masses and remove any drainage pebbles, large plant roots or bulbs. Pulverize any clumps of soil and remove any excess fibrous root masses that may remain. Small particles of roots, leaves or other organic matter are fine to keep, as long as they are not rotting, diseased or harbor any insects or eggs.
Estimate the amount of old potting soil to revitalize before you. Now add 30 to 50 percent fresh compost, peat, or manure to the bin and mix it well with a trowel and your hands. As you add and incorporate the fresh organic material, note the texture and color of the mix. You can stop adding fresh material before reaching a 2 to 1 ratio of old potting mix and fresh organic material per your needs.
Add perlite to the mixture in small amounts, such as a 1/2-cup at a time, to improve the drainage and crumbly texture of the rejuvenated potting soil if desired. Small bits of pine bark, coarse sand or grit can also lighten the organic matter component already mixed in.
Bag the new potting mix for use later or refill the pots from which it was originally emptied.