Plant Doctor Archive

Patchy lawn - 2

Until recently I had a near perfect lawn, but in the last three weeks brown patches have appeared and the lawn looks as if it has been attacked by a virus of some sort. Some of the patches are about a metre long and others are round. This problem has only appeared as the humidity has risen. Can you offer me a solution?

THOUGH drought is often the reason for dead patches in lawns during summer, I think the most likely cause in your case is one or more of the fungal diseases that can sometimes affect lawn grasses. And the recent humid weather has only encouraged the problem.

Once the weather dries up the fungus should cease to be a problem, but you will probably be left with bare patches in the lawn. You can break up the soil in these areas and sow fresh seed, perhaps soaking the area after sowing with Fungus Fighter, Greenguard or Thiram to reduce the chance of further disease. Most garden centres have small packs of lawn seed for repairing damaged lawns.

To reduce the risk of future fungal problems, you could use a catcher to remove the clippings each time you mow. In spring give the lawn a good scratching with a rake to remove the dead grass that builds up on the soil surface and encourages disease.

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