How to reuse spent compost

Tipping out spent compost lets you assess its condition and decide how best to reuse it

Quick facts

Compost breaks down and compacts over time, so it needs enriching and mixing thoroughly before it can be reused for planting

You may need to add a fertiliser if you are reusing compost for hungry plants like roses

Using spent compost for mulching around established trees and shrubs is a good option where it is very old or tired

Getting started

Spent can鈥檛 be added to bins and only some council recycling centres accept it, so finding ways to reuse it in your garden saves you time and effort.

The manufacture, transport and packaging of bagged compost has a large carbon footprint, so being able to use it again for growing plants helps save the planet and saves you the cost of buying new compost each time you replant.

What you鈥檒l need to reuse spent compost:

Gloves
A board or sheet to tip the compost out on
Organic matter, like garden compost , leafmould or well-rotted manure (if replanting)
A garden fork (if digging-in)
A shovel and a rake (if mulching )
and a brush or rake (if top dressing)

Top Tip

Plants in pots are unlikely to suffer soil-borne diseases, so the compost from dead container plants is generally safe to reuse, especially as a mulch around established plants.

Five ways to reuse spent compost

Add organic matter and use it again for planting Tip out spent , remove any large sections of root and work it back to a smooth, fluffy texture with your hands. Then add handfuls of organic matter , like garden compost or well-rotted manure, to create a mixture of around 70% spent compost to 30% new organic matter. This mixture can now be used for planting up containers .

Improve your garden soil by digging-in spent compost Though it won鈥檛 add much in the way of nutrients , it will improve soil structure, helping with aeration and drainage, and in turn will boost soil .

Mulch your beds and borders to lock-in moisture and suppress weeds Use a shovel to pile the compost onto your beds and a metal rake to spread it over the soil to a depth of around 7.5cm (3in). Over time the will be worked in by soil organisms, thereby improving the structure and health of your soil.

Improve the appearance and health of lawns Add spent compost as a top dressing in autumn, mixing it with sand and brushing or raking it into the holes created by spiking ( ). For more information, see our guide to autumn lawn care . Spent compost can also be used to even out dips and hollows when repairing lawns .

Boost an existing compost bin or start a new one Even spent compost will contain a variety of soil organisms that can be put to work breaking down garden and kitchen waste. If you鈥檝e got lots of spent compost to add, do this in layers between other waste. Adding spent compost to the base of new bins can help kick start the composting process.

Top Tip

If you find vine weevil larvae when you come to empty your pots of spent compost, spread the mixture thinly on a tarpaulin or hard standing and wait for the birds to eat the larvae as a tasty treat. Once they鈥檝e found them all, sweep up the compost and use as above.