Annual Meadow Grass / Poa Annua

About Annual Meadow Grass

You’ll find Annual Meadow Grass growing all over the world.  AMG is a very adaptable weed grass that grows and spreads rapidly.   It can be found in arable land, on coastal areas, on tops of mountains and also parks, grasslands, gardens and lawns.

This grass is very shade tolerant and will withstand prolonged waterlogging, although it is sensitive to drought, it is one of the most difficult weed grasses in the world to manage.

Annual Meadow grass flowers and sets seed throughout the year, although it is at its most vigilant in the spring and to a lesser degree again in the autumn.  The plant is capable of reproduction after just one month and it will produce seeds approximately every 10 days.  If you do find it in your lawn it is important that you tackle it early, as there are no selective chemicals you can use to treat annual meadow grass, without potentially damaging or killing the rest of your lawn.   

It is possible to remove AMG but it is difficult and it's time consuming. Preventative maintenance is by far the best way to avoid an infestation.  A good feeding regime throughout the year will help to keep your lawn dense and strong this will make it much more difficult for AMG to get established in the first place.

Identifying AMG

The most common species of meadow grass have a coarse leaf and are approximately the size of a saucer.  The light green colour of AMG means it will stand out against other grasses in your lawn.  The other common meadow grass species is single stemmed, it is not quite as unsightly, but both set seed and spread rapidly.   Neither are not desirable in your lawn.  

Controlling Annual Meadow Grass.

Good Mowing Practice

AMG grows as low as 5mm this means it can avoid even the shortest of mowing heights.  Keep your mower blades nice and sharp, this will help.  Also brushing or raking the lawn with a spring tined lawn rake will encourage the flat stems to stand up making it easier for the mower to cut and remove.  If you have a cylinder mower with a brush attachment this will raise the stems for you. 

AMG weakens every time you mow so the more you do this the better. Cross mowing is also beneficial, i.e. mowing the lawn in a different direction every time. 

It is important to mow the seed heads as they appear, this will be approximately every 10 days.  It is also important that you collect and remove the clippings to prevent the seed heads from setting seed.  This is especially key If you have any weak bare areas in your lawn.  Annual meadow grass establishes fast out competing the other grasses in your lawn.

With a good regular mowing regime it is possible to gradually reduce the amount of AMG in your lawn   

Removing Annual Meadow Grass

If you spot a small amount of annual meadow grass remove the plant with a sharp knife by cutting diagonally into the roots.   AMG is very shallow rooting; it has no underground stems so providing you remove all of the plant it cannot grow back.

If you have a healthy lawn the bare patches will grow back quickly, add a little soil and seed to speed things up if you wish.

A large quantity of annual meadow grass will require a heavier approach if you want to get on top of it.  Wait until the autumn, September is generally an ideal month and scarify your lawn, to pull up the meadow grasses shallow roots.   Don’t be afraid to scarify hard in order to remove as many of the plants as possible and once scarified use a rake to remove any stubborn remaining plants.  

Be warned this process is invasive; you will need to over seed with a good quality seed and then apply a quality fertiliser to encourage quick germination and fast recovery, before the harsher winter weather sets in. 

Annual meadow grass is a very persistent weed grass, it will be radically reduced following this process but you may still find some plants popping back up again in the spring.  Remove any new plants as quickly as possible.   

Feeding your lawn in the spring will encourage the desirable grasses in your lawn to grow, this kick start will help to prevent pesky meadow grass from establishing again the following year.