Weed grasses and how to get rid of them

Weed grasses appear like grasses but are invasive weeds. If you have weed grasses present in your lawn you will notice thick clumps of broad-leafed grass that don’t quite fit in with the rest. So, how do you get rid of them and help your lawn regain its former glory?

Weeding them out

Two of the most common weed grasses are poa annua and couch grass. Equally thick and broad-leafed grasses, there are a few other distinguishing factors that will help you differentiate between the two.

Poa Annua

Poa Annua is easily recognisable by its flowering grass blades and its (almost!) radioactive green colour that will be a different shade to the rest of your lawn. Although more commonly found in lawns that aren’t well cared for, poa annua can appear in even the best looked after lawns as birds drop seeds into the soil and seeds can also lay dormant for years until given the opportunity to grow. Poa annua cannot be cured using a traditional weedkiller, so save your money on solutions that promise this! You should also never try to mow poa annua out of your lawn as this will cause its many seeds to spread and take over your lawn entirely.

How to get rid of poa annua

The most effective way to remove poa annua from your lawn is to cut it at the roots diagonally with a pen knife or similar item when wearing protective gloves. This is called verti-cutting. This works because the roots of poa annua do not go underground, so by cutting it on the surface you will weaken the roots and kill it. Alternatively, you can dig your poa annua up entirely replacing with topsoil and new seed – but be careful with this so that the seeds do not spread.

How to keep poa annua away

As its name suggests, poa annua sprouts annually then dies off – and although you may think this is good news its seeds can do plenty of damage in its time in your lawn. Adopting a good lawn care regime can help prevent poa annua amongst other weeds in your lawn – regularly feeding, seasonally overseeding, and removing any weeds as soon as they appear can go a long way to stopping this weed grass ruining your lawn!

Couch grass

Couch grass is another clump of trouble you’ll find in your lawn, but isn’t quite as recognisable as poa annua with its easy-to-spot seed heads. It also differs from poa annua in that its roots grow underground causing it to spread quickly. Couch grass grows in thick clusters and sports a rather crowded infrastructure of boisterous roots making it difficult to remove from your lawn.  

How to get rid of couch grass

As couch grass roots go under your soils surface, you can’t use the verti-cutting method as used for poa annua. Your best hope of eradicating couch grass is to dig it out – ensuring not to leave any roots behind. Once removed, fill in the missing space with top soil and new seed.

How to prevent couch grass

Like poa annua, couch grass seeds can be introduced to your lawn without you knowing – but one thing you can prepare for is a good lawn all year round. Removing any sign of thicker grasses or weeds when they appear can stop them becoming a huge problem, and a healthier lawn that is well looked after will be in a better position to fend them off. Feeding and overseeding your lawn helps to create a strong grass root system and a thick dense lawn leaving little room for weeds to creep in.

If you have other weeds in your lawn that aren’t weed grasses like these, you can read our guide on how to remove weeds here.