Red Thread in Your Lawn? Don’t Panic
If we get five questions about the same topic in close succession, that’s usually a sign of a significant issue. In the past week or so we’ve had about 20 questions concerning a lawn fungus known as red thread, which would seemingly indicate a big problem is afoot in the lawn across the temperate zones of America.
The good news, though, is that red thread (Laetisaria fuciformis) is rarely a signifiant issue. The bottom line is that your lawn will almost always recover once the weather warms.
Red thread gets its name from a pink fungus that makes the tips of affected grass appear reddish or pinkish. If lawns are a bit hungry, likely in need of nitrogen, and the conditions are cool and moist, then the fungus may take advantage of the ideal situation for fungal growth.
Organic lawns, which rely on the “nitrogen cycling” of soil organisms to really get the soil’s natural systems percolating, can sometimes be more affected by red thread than those treated with synthetic chemicals. The conditions seem to strike when the air temperatures are 60-72 and the soil is 55-65 and, in the worst cases, treatment with a natural fungicide like Actinovate can be warranted.
What’s the worst case? That answer is always in the eye of the lawn beholder. A few circular patches here or there will almost certainly disappear in a few weeks. In the rare cases where it seems to be a bigger issue than your aesthetic threshold can bear, order some Actinovate. You should also clean the blade and undercarriage of your mower immediately after mowing a heavily affected area to keep from spreading the fungus to other areas of your lawn.
And if you suspect that red thread is afoot in your community, then insist that your lawn mowing professional thoroughly wash his or her mower with a solution of either ammonia or hydrogen peroxide before allowing them on your lawn.
And if you suspect that your lawn is, in fact, hungry, then apply a dose of liquid organic fertilizer made from fish meal. The nitrogen in the fish fertilizer is already soluble and likely to be more plant available than an organic granular product.
For more information on red thread, here’s a straight-forward fact sheet from Purdue University: http://www.extension.purdue.edu/extmedia/BP/BP-104-W.pdf