Poa Annua (Annual Meadow Grass)

Description: Small and tufted annual and perennial, pale green in colour.  

Flowering Head: Branched and spreading, triangular in outline.  Spikelets small, containing 3-10 flowers.  Awnless.

Lawn Poa Annua (Annual Meadow Grass)Very common and widespread in all situations and environments throughout the whole of the UK.  Although it can grow and thrive in almost any condition from paths, railway embankments, arable ground to golf greens it especially suited to thrive in wet, fertile conditions.  It can be introduced to turf via bird droppings, worms through casting, animals such as moles, rabbits, foxes, cats, dogs and finally, humans via mud on the soles of our shoes or on car tyres, lawnmowers etc.  The seeds of annual meadow grass can remain dormant and viable within the soil for up to five years and when growing conditions become favourable they will germinate, thus meaning, a domestic lawn can be annual meadow grass free for four years then suddenly in the fifth year you can have an explosion of annual meadow grass due to the viability of the seed sitting in the seed bank.  It is able to propagate so successfully due to its ability to withstand such low cutting heights in turf situations and to withstand heavy wear and traffic.  With such precise cutting regimes applied on golf greens and cylinder mowers able to cut down to a height of 3mm it is very common to see annual meadow grass throw up seed heads at 2mm to compensate for this. In a domestic lawn situation it is nigh on impossible to remove seed heads with rotary mowers that can only get down as low as 10mm. 

Annual meadow grass can flower at anytime throughout the year, however in the west coast of Scotland this is especially prevalent during the month of May when the small shimmering silver like seed heads can be seen glistening on golf greens, much to the annoyance of the golf course managers, however, this is short lived and the heads will soon fall off.  The old adage “it is better to work with nature rather than against it” is especially applicable with head green keepers having through experience adopted a certain strategy to not only work with annual meadow grass in their greens but actually encourage it.  Throughout the west coast of Scotland it is very common for golf greens to have an annual meadow grass inclusion of 50%. It is far better to have annual meadow grass encroach into a golf green or domestic lawn as opposed to other rank grass weed species such as Agricultural Perennial Ryegrass, Yorkshire Fog or even worse, Moss. 

Myth – “Annual Meadow – grass seeds are present in bags of grass seed”

The act of parliament seeds regulation states that all seed sold in the UK must be certified with purity and germination rates being 98% and 90% respectively.