Grass mowings are an important ingredient of the home compost bin:
They generate heat, speeding up the composting process
They introduce moisture, balancing dryer ingredients
They contain important amounts of nitrogen and so enrich your compost

Grass that has been treated with feed and weed containing clopyralid should not be used around the garden as this chemical is very persistent and can harm the growth of other plants.

Up to 15cm depth of grass mowings can be added to any home compost bin at one time.
A deeper layer will go slimy and smelly unless it is mixed up with dry, light materials like, preferably shredded, prunings, or shredded paper. These absorb some of the moisture from the grass mowings and create air pockets.
The micro-organisms that do the composting for us need little air pockets, but the micro-organisms that can operate without oxygen are the ones that produce unpleasant smells.

Other ways to use your grass mowings are:
Make a special grass composting bay. If your garden produces a lot of mowings in comparison to other types of garden waste you may need a special composting unit for this. It should have fairly open sides, like wire netting or old palettes. These allow some of the heat and wet to escape.
The mowings should be layered with dry, open materials such as shredded prunings; we have found these to be the best. Shredded or crumpled paper (balled as if you were going to use it to light a fire) also works but takes at least two years to break down.
These special grass bays are best used on a three year rotation: fill one year and leave for two years to rot down. After this length of time there will be good compost to use in the garden.

Grass mowings can also be used as mulch round shrubs and trees. Spread a thick layer of newspapers or cardboard on the DAMP soil surface to prevent weed germination and cover with grass mowings. Top up the grass as it dries and shrinks.

Fresh grass mowings generate a lot of heat so you can use them as an instant hot bed on which to plant courgettes or squashes. Dig out a patch, roughly 30cm square and 30CM deep. Pile up fresh grass mowings to come to the level of the surrounding ground and cover with the soil you have dug out. Excavate a well in the centre of this heap and fill it with home made compost. Cover the whole thing with a permeable membrane like Phormisol, this holds in the moisture and heat and stops weed growth. Cut an X in the membrane and plant your courgette or squash through this into the compost filled well. Water copiously.

Grass mowings are slightly acidic so they make a good mulch for acid loving soft fruit like raspberries and gooseberries. They are also useful spread as a mulch along the side of tattie dreels: they keep in the moisture and slightly acidify the soil, helping to prevent scab.

The heat produced by fresh grass mowings can be used to kill perennial weeds like ground elder and nettles. Fill a plastic sack with half mowings and half perennial weed roots, tie tightly and leave in the sun for a month. The weed roots will rot to a slimy mess which can be added to your home compost bin and quickly covered with general garden waste.

If you still have more grass mowings than you can cope with, consider producing less. Why cosset and feed your lawn so that it grows so fast that the job of mowing becomes a trial?
Stop feeding the lawn
Do not water the lawn – even brown grass comes back to life once the rain returns
In sunny weather sometimes leave off the grass box and let the mowings lie. These will give the grass a little nutrient for free. The worms will quickly take the little bits of grass down into the soil, as long as you haven’t poisoned these useful creatures with herbicides and moss killers.
                                                     Draw up a deck chair and enjoy the garden.