Red Thread & Pink Patch
Red Thread: Enlarge for close-up courtesy STRI
*Lawn Fertiliser & Liquid Feed Products, useful in the control of red thread are available in the Lawnsmith Shop
____________________________________
Of all grass diseases red thread lawn fungus is the most common. In fact I would pretty much bet that your lawn has it every year and you more than likely have never noticed.
The disease or fungus causes the grass leaf (not the grass plant) to die often giving the lawn a blotchy appearance. Whilst the disease is active the blotches will have a pink colouration and on closer inspection you will see 2mm long pink threads or needles.
Red thread attacks from May onwards favouring humid and mild weather. Early and late summer temperatures with a dewy grass are ideal though the drying effect of summer on your lawn can disguise the disease leading most people to assume wrongly that the lawn is just suffering from drought.
In recent years we have experienced very wet summers which also present ideal conditions. In these years the red thread fungus has been very obvious as the pinky or orangy blotches have formed in otherwise healthy green lawns.
Red thread is often accompanied by another disease or fungus known as pink patch. This appears at the same time but presents itself as tiny pin head size blobs a bit like candy floss.
Finally, some lawns will be affected more than others. The following conditions may increase severity of attack:
-
Old or compacted lawns
-
Young lawns that have not had chance to build up resistance
-
Lawns that become stressed due to drought, heat or water logging
-
Lawns that have little air movement and hold the dew well into the day
-
Lawns that are watered - light frequent watering in the evening in warm weather will guarantee an attack!
-
Late spring scarifying thereby weakening the grass and making it more susceptible to an early summer disease
Remedy
Though fungicides are available you are going to need to be on the ball as treatment prior to attack is the best way to control this disease. You will also need to treat several times in a year and as treatment prevents the grass building up its own resistance to the disease you will get locked into an an annual cycle of treatments. Personally I wouldn’t bother and just do your best with lawn care practices to reduce its impact. Once conditions improve the lawn will recover with no lasting damage.
The most important control measure is to maintain a good supply of nitrogen in the turf to promote growth. This enables the disease to be mowed out. A fertiliser containing potassium is often preferable. Any of the Lawnsmith Spring & Summer Fertilisers* will provide the correct nutrients. In addition:
- Remove clippings after mowing
- Water deeply and infrequently only if conditions are dry
- Do NOT water in the evenings
- Anything you can do to improve drying will help e.g. reduce shade, improve air flow, squeegee the moisture off the lawn by brushing or dragging a garden hose across it etc
- Once the disease has ceased aerate and possibly scarify the lawn to improve drying and remove thatchi that harbours fungal spores
