Why is my lawn patchy?

Why is may lawn patchy- When rogue grasses make your lawn look “spotty”

They say the only things certain in life are death and taxes; some gardeners, however, may also wish to include reasons why their lawn is patchy – annual meadow grass. Ubiquitous, difficult to get rid of and continually seeding, that revised statement probably holds true for everyone with a lawn in temperate climates across the globe.

What is annual meadow grass?

Annual meadow grass is the grass you see growing where no others will – rooftops, gutters, cracks in the pavements – and, given a chance, your garden. Though it doesn’t pose a real threat to your existing lawn (it won’t take over the existing grasses or sap many nutrients away from them) the effect it has on your lawn’s appearance can be a real headache for some.

Picture Credit Harry Rose

Since annual meadow grass is far coarser than most fescues found in household or ornamental lawns, it appears quite distinct from the grasses around it. The fact that it carries seed heads throughout the year, even when mown very short, and is usually a slightly lighter colour than the surrounding grasses will make your lawn look patchy.

This should be particularly obvious at the current time of year when the finer grasses will have finished growing whilst the coarser annual meadow grass continues. Frosts will exaggerate this effect as these will affect annual meadow grass less than traditional lawn varieties.

How does annual meadow grass appear in a lawn?

How does it find your way into your lawn in the first place? Perhaps most worryingly, it may have been present in your lawn before it even was yours. Some turf growers’ seed mixtures can contain annual meadow grass but it may only become more obvious if the rest of the lawn deteriorates, even if it wasn’t apparent when the turf was delivered.
Though choosing a reputable turf supplier is always wise it won’t make you immune to annual meadow grass: it is easily introduced to established lawns by bird droppings, from top soil added either as topdressing or before the lawn was laid and even by the wind if it’s growing widely nearby.

Alkaline soils are especially susceptible since other grass species don’t grow as well so annual meadow grass has less to compete with.

Dealing with annual meadow grass

Dealing with annual meadow grass one established isn’t easy, but you can find advice here:

Chemical treatments

Sadly there is no weedkiller that will kill for annual meadow grass (poa annua) without damaging the rest of the lawn. So no quick fix solution ……

For small lawns: spot treat the rogue plants with glyphosate or a similar systemic weedkiller.  This will kill the roots as well as the leaves.  Just be careful not to splash any onto the plants you want to keep!

Non-chemical ways to get rid of annual meadow grass

If you’re not a fan of chemical weedkillers, slicing through the base and roots of each plant with a sharp knife will it.

Keep desirable lawn grasses healthy

A regular lawn care regime will help the grasses you do want to out-compete the ones you don’t want.  Start by feeding your lawn when the soil starts to warm up in March/April.  Feed every 6-8 weeks throughout Spring, Summer and Autumn.

Mow little and often and remove clippings.  This will take away most of the annual meadow grass seeds and it will keep the lawn looking neat and cared-for…..a great way to detract the eye from uneven colouring.

Refrain from watering your lawn in summer – OK so it may go a bit brown, but annual meadow grass really hates drought.  If it’s deprived of water, this shallow-rooting plant soon withers and dies.

A stitch in time saves nine!

Keeping your lawn healthy, lush and dense will make it harder for any seeds introduced by birds or on the wind to establish themselves. If you do begin to spot annual meadow grass, dealing with the problem early is vital.

More lawn care advice

You might like some of our other blog posts on keeping your lawn hale and hearty