Leave them on the lawn if they are short and dry. Otherwise the heap, the compost or the collection — each with a condition.
Leave them
The default when the lawn is cut often and the clippings are small. They break down within days, return what they contain, and nothing has to be carried anywhere. This is mulching, and it stops working the moment the material is long or wet.
Compost them
Clippings are the classic green material in a heap: wet, nitrogen-rich and fast. What they cannot be is the only material. A heap of pure clippings compacts, excludes air, goes anaerobic and turns into a grey slime that smells.
Mixed with something dry and coarse — shredded prunings, cardboard, autumn leaves — they compost quickly and well. That mix is the reason the shredder shelf on this site sits next to the mowers: the two outputs are made for each other.
Heap them separately
A pile of clippings at the back of the garden does break down eventually, and it does it faster if it is turned. It is the least effort and the least useful result.
Take them away
Green waste collections and civic sites accept them. The only thing worth knowing here is volume: fresh clippings are bulky and heavy, and a season’s worth from a large lawn is a great deal more than people expect.
Where the catcher figure matters
A catcher volume in litres is a real, stated dimension on this shelf. Its importance is not what it holds but how often you stop: a 50-litre bag on long grass is four stops where a 70-litre one is three.
On a wet cut the effective volume is much less than the stated one, because the material packs and the airflow gives up before the bag is full.
How this site handles it
Mower pages print the catcher volume as the maker states it and call it a stated volume. The catcher shelf lists replacement bags and boxes by the machines the maker names, because on that shelf the fit is the whole specification.
The questions that keep coming in
Can I put clippings straight on a border as mulch?
In a thin layer, and dry. A thick layer of fresh clippings mats, heats and excludes air, which is the opposite of what a mulch is for. Spread thinly and allowed to wilt first, they are fine.
Do clippings from a treated lawn matter?
If the lawn has been treated with a selective weedkiller, the clippings can carry it into a compost heap and from there onto a vegetable bed. What any particular product requires is on its own label, and this site does not interpret labels.
Last reviewed 26 September 2026