Pasture Watch

A real stinker

Why is it a weed?

Invasive plant that colonises pastures and outcompetes desirable grazing species

Where is it found?

Nationwide

Is it toxic?

No

Other uses

Extracts have been used for bacteria control

IT HAS a pretty flower, and it stinks.

Stinking mayweed (Anthemis cotula) is a member of the same family as the similar-looking chamomile, and I get a lot of calls about it as it blooms over summer.

It tends to be a fairly low-key, lowgrowing plant, infesting bare soil and growing untouched as it's not very palatable. Cattle don't like it, and sheep only graze it if there's nothing else to eat.

Then, suddenly it seems, it's in full flower and too big to control.

While it's generally only a nuisance in summer, its seeds can germinate at any time of year if the soil is moist enough.

Plants usually die off after going to seed, but if they're prevented from seeding – for example, if they're mowed off while flowering – they may survive over winter.

How to control it

Stinking mayweed seedlings are weak, slow-growing, and can't compete against healthy pasture plants. Easy ways to avoid an infestation are:

• don't over-graze pasture;

• don't allow soil to become pugged;

• maintain healthy soil and pasture.

If you spot the odd plant, pull it out by hand and sow grass seeds in its place.

If you have a large area of plants that haven't gone to seed, regular mowing will stop it from seeding. You can then spray it out when it begins growing again in spring.

If you want to use a chemical, it's best to target seedlings, so you'll need to check pasture carefully to find them. Clover-safe options are:

• flumetsulam, ie Headstart, Valdo;

• bentazone, ie Dynamo, Pulsar. If plants are larger, use a spray containing clopyralid such as Versatill PowerFlo ™ or Archer 750. However, while Versatill PowerFlo ™ or Archer 750 are grass-safe, they will kill clover.