Annual Poa

Poa annua

Annual poa (Poa annua), also known as annual meadow grass, is a fast growing annual grass found throughout New Zealand in a wide range of crops. While individual plants tend to be small, populations of this grass weed tend to be large and they then compete for light, nutrients and water. Poa annua is best identified by the boat shaped tips to its leaves and the two parallel veins (often referred to as tramlines) that can be seen if the leaf blade is bent backwards. Germination takes place throughout the year and is set very quickly meaning populations soon increase.

Related Weeds

Chickweed

Stellaria media

Chickweed (Stellaria media) is a widespread, very resistant weed, it is found in the North and South Island in areas of cultivated land and roadsides. Commonly seen in winter, it does not favour drier conditions. It is a problem in small grain crops such as barley, causing up to 80% yield losses. It a low growing spreading annual (up to 40 cm) with, light green soft leaves, (lighter underneath) up to 2 cm long. The leaves are in opposite pairs on hairy stalks. Flowers are white, about 1 cm in diameter, with 5 deeply divided petals that appear to be 10 petals. Chickweed flowers and sets seeds simultaneously. The seeds are contained in green egg-shaped capsules, and one plant produces about 15,000 seeds, which remain capable of germination in the soil for up to 5 years.

Cleavers

Galium aparine

Cleavers (Galium aparine) are a common, widespread annual weed found throughout New Zealand. A significant weed of cereal and horticultural crops and often found scrambling up fencelines and hedgerows Cleavers have a scrambling, clambering growth habit and “stickiness” due to tiny hooks on its stems and seeds.

Cornbind

Fallopia convolvulus

Cornbind (Fallopia convolvulus) also known as Black-bindweed, is a climbing, spreading vine that grows to 1 – 1.5 m long with stems that twine clockwise around other plant stems. The leaves are arrow-shaped up to 9 cm long by 6 cm wide. The flowers (November to April) are pale green, small and grow in clusters closer to the ends of the stems. Seeds are triangular and shiny black. Cornbind is more commonly found in the South Island (South Canterbury), but is showing up increasingly in cultivated areas in Hawkes Bay and Wellington.

Fathen

Chenopodium album

Fathen (Chenopodium album), pronounced fat-hen and sometimes called fat hen, is one of the most serious weeds of cropping throughout New Zealand. It is an annual that germinates in the spring and early summer and then dies off in the autumn with frosts. Fathen is an extremely vigorous weed that can quickly outcompete and smother crops. An upright plant that can grow to 2 m tall and is a prolific seeder.

Broad-leaved Dock

Rumex obtusifolius

Broad-leafed docks (Rumex obtusifolius) grow prolifically throughout New Zealand. This is the most common dock weed found around farmyards, in damp arable & pasture land, wasteland and gardens.

The leaves are very large and broad (up to 35 cm long and 15 cm wide) hairy underneath, and have long stems. The plant can grow to 1 m tall. Flowers appear from July to April and are usually small, green (sometimes red) and inconspicuous, carried above the leaves in clusters. The root is a strong thick perennial taproot, enabling easy regrowth. Seeds are a reddish brown.