Red Thread - the low down on the red menace
Updated: May 2
The recent wet and humid June 2019 weather has created the perfect conditions for the red menace on your lawn. We have taken a large number of enquires from customer reporting small red/brown patches in their pawns over the past few weeks. Whilst this is alarming when the lawn was lush green before, rest assured in most cases its temporary and a solution is available.
What is red thread?
Red Thread causes small patches of grass to turn pink/red later turning light brown/bleached in appearance. Red thread can affect any lawn and is one of the most common lawn fungal diseases in the UK. You may have had in infection and not know about it as it can simply infect a tiny patch of lawn but when very humid it can soon spread and be more visible. Occasionally you may also see small pink fluffy material in the affected areas the grass too. Infected areas will usually regenerate in a few weeks as the red thread does not usually kill the grass plant, only the blades of grass.
How does red thread it get into a lawn?
The red thread fungal spores are usually dormant in the lawn until optional conditions arrive. Usually soon after a period of high humidity and/or wet weather, typically Spring to early Autumn.
What can be done to treat red thread?
Apply a nitrogen lawn feed. Sometimes the cause is due to low nitrogen but even a well maintained lawn, including sports turf can easily get infected if the weather is humid.
Apply a lawn fungicide. This cannot cure any existing infection. Instead it reduces the chance of it spreading to other areas on the lawn. The effect is short term and preventing the infection provides a better long term approach (see below) Most fungicides can only be applied up to two times per year, otherwise you introduce resistance to the treatment. Fungicides are suitable when you have a widespread infection but you need to apply soon as you notice the infection. Fungicides will affect the beneficial fungi in the soil too so fungicide use is only advised when absolutely necessary.
Whilst the grass should regenerate, severe infection may require patch repairs. Rake out the dead grass and patch repair with seed/fine top soil/top dressing, water to ensure the seed remains moist until its germinated.
How to prevent red thread?
Follow an annual lawn care plan of fertiliser to ensure the correct nutrition is applied. This makes the grass more hardy and resistant to attack. You may still get red thread but the grass can fight it off and recover faster.
Reduce lawn thatch by scarifying.
Improve surface drainage and reduce soil compaction by aerating.
If your lawn soil is very poor and grass is struggling to grow, you may have to consider replacing it.
When watering the lawn, do so early morning to allow the moisture to dry off the grass during the day. Watering in an evening or night can leave moisture on the grass blade, leaving it more likely to become infected.
Ensure your mower blades are sharp. Blunt blades damage the grass, wearing them and making them more prone to infection.
Do not cut more than 1/3 off the height of your grass at any time. Reduce gradually by thirds to the ideal height. Cutting the lawn too short in one go stresses the grass and weakens is ability to fight off disease.
Contact Lawn Tiger who are best placed to advise about the lawn condition and a suitable treatment. Lawn Tiger’s year round treatment plan will ensure your lawn receives the correct nutrition and will improve the health and appearance of your lawn.