Nettles

Biology of Nettles

There are numerous nettle species world-wide, many of which are trees or shrubs. Within Europe only two occur as weeds:

Small Nettle
Urtica urens – annual

Stinging nettle
Urtica dioica – a perennial and the most prevalent species in established pasture

• Propagates mainly from extensive, creeping, rooting stolons.
• New plants are able to develop from root sections, so that chopping them does no more than multiply the problem.
• The more often the shoots above ground are cut, the more vigorous is the new growth.
• They will grow upto a height of 1 metre, eventually forming dense beds, which spread out across the field.
• Flowering period is from June to October.
• Germination occurs from the soil surface, even at low temperatures, when the grass sward becomes open or if the soil is disturbed.

Impact on the sward:

• Grass yield / grazing is lost mainly by competition from nettles for nutrients, light and moisture, but also from stock refusing to graze close to nettles.
• The quality of the conserved grass (hay, silage) is affected if nettles are present, as the stock will reject it.