Why does grass turn yellow in the winter?

In the UK, the winter months of December, January and February are cold and dark. There can be as little as 8 hours of daylight per day, and most of this can clouded over. Many plants hibernate through the winter because it is not worth them trying to make food. Trees drop their leaves and herbaceous plants die completely back to ground level. The winter can be very bleak, with very little green in the countryside.

Cool-season grass has evolved to tolerate the winter. It can keep green leaves through even the coldest temperatures. Through snow and frost. The temperature of the soil determines the rate of growth of grass. When cold weather strikes, grass growth slows right down.

Yellow leaves on a lawn

Leaves on grass plants can become desiccated from cold winds. Fungal infections take their toll on old leaves. Grass also pulls in it’s food reserves into the core of the plant to keep it alive during the slow months.

New leaves are not regrown, so these damaged, old leaves remain on the lawn to turn brown. The rotting and decomposing processes in the lawn and soil also slow down. Material does not get recycled in to nutrients as fast as it does in the summer.

Chlorosis can also be a factor. This is caused by a lack of Iron in the soil. The grass will be struggling to find the right nutrients.

As a result, lawns can look very tired and worn out during the winter. Grass lays over and contains a lot of discolouration.

The good news is, there is often nothing to worry about at all. All lawns go through a difficult period in the winter of looking untidy.

If you would like to tidy your lawn, run a mower over it on a high setting. This will clear out the winter debris, twigs and old grass leaves, improving the look of the lawn.

Look out for fungal infections

Old, weak grass leaves and low nutrient levels can expose grass to fungal diseases. Keep an eye out for red thread and fusarium disease. If you spot any signs, a winter feed of Potassium will help to give the grass a boost, especially if it has been a wet winter.

Treat the lawn with a fungicide during the winter if an fungal infection does become rampant. Contact your local lawn care service for more details.

Patience is the key for winter lawn care

The main aim of winter lawn care is to bring your lawn through to the spring with as little damage as possible. As soon as the temperature rises, new leaves will grow and your lawn will transform to be lush and green. Don’t worry about some grass leaves turning yellow in the winter, this is normal.