Yarrow

Symptoms

Plant spreads by underground stems and seeds and produces large drought-resistant patches in lawns, so grass cannot spread.

Find it on

all over the garden, but especially on soils affected by drought or lacking in nutrients

Organic

The most effective organic approach is to weaken the plant by hoeing it wherever it appears in beds or borders, or to dig it out using a fork or trowel. If it establishes itself in the lawn you will have to dig out chunks of grass to get it out effectively, but you can hold it at bay by keeping the lawn healthy and thereby making conditions less favourable for the yarrow. Top-dress the lawn in spring and in September, mow it regularly and lightly rake when in growth to weaken the weed.

Chemical

Yarrow is fairly resistant to many selective weedkillers, but in lawns, use a weedkiller such as a 2, 4-D-based herbicide to remove the weed. Apply in cool, moist, calm conditions when there is least risk of accidentally damaging nearby garden plants.