Chickweed is now growing and can smother established grassland or young leys. So says Nicola Perry, grassland specialist with Corteva Agriscience, adding that its prostrate growing habit allows it to rapidly colonise any gaps in the sward.
“Chickweed will be found in established grassland, often in damaged areas or where slurry injectors have opened up the sward,” says Dr Perry.
‘It is also the most common weed to invade newly sown leys. It will aggressively compete with grass species for space, light, water and, most importantly, nutrients. So it needs to be controlled.”
Individual chickweed plants can produce 1,300 seeds and it only take five to six weeks from germination to seed dispersal. Plants are capable of four to five generations a year and seed buried in soil can remain viable for up to 25 years.
Dr Perry recommends tackling chickweed with the herbicide Envy, which can be sprayed from now until the end of November.
One of the two active ingredients in this product allows it to work at cooler temperatures and also when there are dramatic fluctuations between day and night.
This means, if ground conditions allow, it can get to work before the chickweed flowers and before it significantly impacts grass growth.
It can be applied on chickweed at a rate of up to two litres per hectare in established grassland and at a lower rate of one litre per hectare in newly sown leys.
“Removing chickweed from young leys allows productive grasses to tiller out and spread across the ground,” adds Dr Perry.
Envy has excellent grass safety and is rainfast in two hours. Mandatory stock exclusion is seven days. It is also an excellent herbicide for buttercups and dandelions, but it will kill clover.