Wondering why to put hay on grass? What you need to know about mulching your lawn with cut grasses

Should you really be mulching your lawn with hay? And will straw work better? Your lawn care question answered

lawn care
(Image credit: Alamy)

Should you be putting hay on your lawn? This practice has been a source of confusion, since some gardeners don't put anything at all on their lawns, while others swear by mulching it with hay or straw. Putting hay on lawns is often mentioned as part of spring lawn care tips. Will it make a difference if you do mulch it, and what is the correct material to use? 

Why put hay on grass?

path leading to summer house

(Image credit: David Giles/Future)

The idea behind putting hay on grass is helping new grass seedlings establish. This method is used for protecting grass seed from birds and protecting young grass seedlings from scorching sun. Covering your lawn when you're seeding it helps the ground retain moisture better, which improves grass germination.

So far so good. But is putting hay on your lawn really a good idea? Shouldn't you actually be using straw? 

Hay or straw?

A beautiful garden with a well-tended lawn

(Image credit: Alamy)

Hay and straw are not the same. As Joel Karsten writes in Straw Bale Gardens Complete, a hay bale 'contains all the seed heads inside the bale, is usually green colored, heavy...and is delicious and nutritious for livestock.' However, precisely because hay contains seed heads, it is 'less desirable' for gardens. All those seed heads may well sprout on your lawn, leaving you with a lot of weeding to do. 

Straw, on the other hand, does not contain seed heads, is light and dry, typically yellow in color. Straw makes for an excellent lawn mulch, it 'will help to hold the seed in place and slow the drying of the soil', according to Taunton's Lawn Guide

If you are seeding a lawn, using a fine sprinkling of straw as mulch is a great idea if you live in a hot climate, an area prone to drought and winds, or are experimenting with wildlife garden ideas but want to keep your new lawn protected. 

When should you not use straw on your lawn?

lawn in garden

(Image credit: Polly Eltes/Future)

If you live in a humid climate that already gets plenty of rain, you don't need to mulch with straw. If anything, straw might do more harm than good in this type of climate, because it is likely to grow mold and introduce it to your lawn. 

If you want to add extra nourishment to your lawn, choose the best lawn mower that has a mulching attachment and scatters the grass clippings as it goes rather than collecting them in a bag. 

Anna Cottrell
Anna Cottrell

Anna is a keen urban gardener, with David Austin roses and Japanese acers among her favourite plants. She moved into the world of interiors from academic research in the field of literature and urban space a couple of years ago. She's always been interested in how people make houses into homes, and how our concepts of what's stylish change over time.