20160423A.jpgAs you repot your houseplants into fresh soil, remember the old soil you’re removing, now too dense and too overly rich in mineral soils for reuse directly as a potting mix, can still have a second life.

The most obvious thing to do is simply to add it to your compost bin. Since it is extra-rich in minerals (mineral salts tend to build up in houseplant soil over time), it will stimulate the microbes present in the compost to work even more diligently, resulting in faster composting. In addition, the roots it contains decompose quickly, adding yet more humus to the compost you’re creating. Don’t worry about the presence of perlite and vermiculite in the mix. They are simply expanded rocks and no more harmful to the environment than particles of sand would be. They’ll help structure the compost when you use it in the garden later.

Another possibility is to mix old houseplant soil into the ground as you plant or transplant perennials, shrubs, vegetables, etc. Consider it to be the equivalent of adding compost to the soil.

Or simply spread the old mix over the soil among established plants (perennials, shrubs, etc.), again just as you would do with compost. They’ll then be able to profit from the minerals the used potting mix will release.

In fact, about the only thing you shouldn’t do with old potting soil is to throw it in the trash: that would be a waste!

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, laidbackgardener.blog will continue its mission of demystifying gardening and making it more accessible to all.

0 comments on “Recycle Old Houseplant Soil

Leave a Reply

Sign up for the Laidback Gardener blog and receive articles in your inbox every morning!

%d bloggers like this: