Danger Poa annua

Poa annua - Annual meadow grass

Poa annua (Annual meadow grass), the nightmare of every greenkeeper and field manager. Annual meadow grass is one of the most common grass species. It is an annual, sometimes biennial and occasionally perennial meadow grass (Poa) with shallow roots. Annual meadow grass flowers at an early stage and its height does not exceed 25-30 cm. However, this plant will usually remain much shorter.

How to recognise annual meadow grass

Annual meadow grass is usually easy to identify. The youngest leaf will appear in a folded shape. There are no auricles at the base of the leaf, and the underside of the unribbed leaf is matte and often pale green in colour. This colour difference is often clearly visible in a field. Furthermore, Poa annua has a long and milky-white ligule. In a field, annual meadow grass can easily be identified by its abundant seed formation. After all, it flowers year-round. The leaves are unribbed, which means that they are soft and wavy.


Low wear tolerance

The wear tolerance of annual meadow grass is moderate to low, partly for reason of its shallow roots. This means that the grass is easily kicked or hit away, which may result in many bare spots that will significantly reduce the quality of play on a sports field or golf course. In addition, annual meadow grass has an unattractive appearance.


Appearance of annual meadow grass

The appearance of annual meadow grass is unattractive. Poor nutrition will change its mid-green colour to a lighter green. The colour will change in dry conditions and when there is insufficient moisture in the top layer, annual meadow grass will immediately turn light green and then begin to flower profusely.


Early germination

Annual meadow grass germinates at soil temperatures as low as 7 - 8 °C. When the fields have been played bare, annual meadow grass will often be the first to appear as most grass mixtures germinate at higher temperatures. This means that the bare patches are filled in fast and the good thing is that there is a green field, which is always better than nothing. However, this benefit does not outweigh the disadvantages. Annual meadow grass can be tackled by, for example, SOS® from Barenbrug. SOS® germinates at approx. 4 °C, which means that it is virtually impossible for annual meadow grass to establish itself.