Plant Doctor Archive

Patchy lawn

THIS winter yellow patches appeared on my lawn, which eventually turned brown. Now the surrounding grass is growing well, but the lawn looks unsightly. Can you tell me what the problem is and how I can fix it?

FROM your photo it looks like the dead-looking patches are kikuyu grass that has been killed off by heavy frost, while the surrounding greener areas are ryegrass which is more tolerant of cold weather. In warm parts of the country, many established lawns contain kikuyu, which has moved in as a weed and, depending on the conditions, can become the dominant grass in the lawn.

Of African origin, kikuyu is frost tender and can be knocked back quite severely in winter, leading to the patchy symptoms you describe. The good news is it will recover as the weather warms up. The kikuyu stolons (creeping stems) usually survive the winter and start sprouting again in spring, but it may take a few months before your lawn is back to normal again.

You could break up the soil in the bare patches with a rake and sow a small amount of fresh lawn grass seed, which should germinate quickly in the next few weeks to fill up the bare areas.

Kikuyu is often considered a weed because of its tendency to spread into garden borders and up fencelines, but on the upside is its ability to survive summer drought, wear and tear and poor mowing practices better than many of the so-called "quality" lawn grasses.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.