Can You Reuse Compost? Garden Recycling 101

Last Updated on April 5, 2024 by Real Men Sow

It’s great fun to grow plants close up, but container gardening can be expensive in terms of potting compost. That’s why it’s not worth wasting it. There is a chance to reuse potting soil in next year’s containers or use it to solve gardening problems.

How To Reuse Compost?

First, let the potting compost dry in pots, or on a tarp.  Although old potting compost does not need to be dry, too much moisture can make it a breeding ground for moldy microbes. Dry soil weighs less, too.

Storing Potting Compost Before Reusing

It is important to keep the potting compost that is for growing edibles apart from the soil that supports flowers. This helps to limit disease transfer from year to year, just like the rotations in the vegetable garden. You can use the soil that you used to grow flowers this year for edibles next year. Any container that keeps the soil dry, such as bins, small garbage containers, or heavy-duty plastic bags can also be reused.

How To Store Old Potting Compost

Storing potting compost in freezing temperatures is a good idea, as it makes life more difficult for any insects, whether they are adults, pupae, or eggs. Used potting compost can cause mysterious hatches if it is kept in warm temperatures..

Good Uses for Old Potting Compost

Your old potting soil should no longer be used for potted plants. This is because it lacks nutrients but your old potting soil still has nuggets and threads of humus as well as very few weed seeds.

It is ideal for covering new carrots, beetroot, and other slow-growing seeds. Topdressing with moisture-holding potting soil improves the germination of the seeded crop by reducing competition from weeds.

Fill up holes in your garden

When moles, dogs, or other animals make holes in your lawn, potting compost can be used to fill them in and repair them. A thin layer of potting soil is sufficient to cover grass seed and prevent it from catching on fire.

Old potting soil can also be used to pot up giveaway plants. You can share divisions from daylilies, bee balms, and asters. It’s free to drop them in a plastic pot and then fill it with used potting soil.

Reusing Potting Compost

Mixing used potting soil with new material is a common method of gardening. Many gardeners use about half the amount of each and add a handful of organic fertilizer to increase plant nutrition. You can also place old potting soil in large containers and then fill them with fresh material.

Does the weather affect reused compost

This simple procedure works well for soil that is healthy, but in a  humid climate, blights are a constant problem. You’ll have to heat treat potting compost that was previously used to grow edibles. Most disease pathogens can be killed in just 30 minutes at temperatures of 120°F (49°C). However, you don’t have to stink up your house with your oven.

Instead, place a few gallons of used potting soil in a bag and set it in a transparent storage container that is in direct sunlight on a sunny day. Also, a parked car with its windows rolled up can be used as a solarisation chamber. After the potting compost is cooled and heated, it can be added to any new mix you create.

Keep using fresh bags of seed-starting mixture for starting seeds, then save time by storing and recovering soil from outside containers.

Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.