How to care for your lawn in winter

Start by identifying what type of lawn you have at home, as this will help you determine the growing conditions and care required to keep it lush and healthy. The most common types of lawn in Australia are buffalo, couch and kikuyu. These are known as warm season grasses, as they grow best in temperatures between 20 and 32 degrees Celsius. They also tolerate heat and drought better than cool season grasses.

In the cooler months, these grasses will grow a lot more slowly and won’t be as green as usual, but this will change when spring comes – warmer weather will bring back the green and vibrant flush. Buffalo and kikuyu are ‘self-repairing’, which means they’ll bounce back from any stress they encounter over winter. (Couch does this, too, but only once it’s fully established.)

In the cooler months, it’s best to water your lawn sparingly, if at all. Higher rainfall and reduced evaporation means there’s no need for extra water. In cooler climates where couch, kikuyu and buffalo lawns are dormant, turn your irrigation down to the minimum (once a week or fortnight) or switch it off. Over-watering can result in over-saturation, which can compact the soil and prevent its nutrients from reaching the lawn’s roots.

If you live in a tropical area, you can water a little as needed, but do this early in the morning to give the lawn a chance to dry out by nighttime. This helps prevent rot and fungal diseases.

It's easier for weeds to take over in winter when the lawn is dormant. The most important thing you can do is to remove weeds as soon as you spot them, so they don’t get a chance to go to seed. If they do, they’ll spread quickly.

There are two methods of weed control: herbicides and manual removal. Herbicides may be selective, or all-purpose, but either way they are designed to kill plants – including lawns, so be careful to choose the right one for your grass type. Read and follow the instructions on the package carefully for the best results. Apply herbicide on a windless day, with no rain forecast for two consecutive days. Note that herbicides are also more efficient in warmer months, so it takes longer for them to work in winter.

If you have pets, consider using a pet-friendly herbicide or remove weeds manually. A weeding fork gets the job done, or try a weed puller to make life a bit easier. No matter what method you choose, be sure to get weed out from the root, otherwise there’s a chance it will just grow back again.

While the lawn is dormant, it’s a good time to improve the soil quality with a lawn and soil booster or lawn tonic. Soil boosters will help improve the microbial activity in the soil, which will help with nutrient uptake. Lawn tonics, like seaweed-based solutions, can be applied every month to help the lawn cope with cold weather or frosty snaps.

As a general rule of thumb for the cooler months in cold climates, mow only when the lawn needs tidying up. In tropical areas, you can mow more regularly without stressing the lawn. In both climates, it’s best to keep the grass longer than usual, especially in shady areas.

Couch can be mowed lower than broader-leafed grasses like buffalo and kikuyu, but generally keep the grass double the length in winter compared to other times of the year. Mow couch to 15mm in summer and 30mm in winter, and buffalo and kikuyu to 30-40mm in summer and 50-60mm in winter.

Tip: If your lawn is in the shade, double these figures. If you’re in the tropics, follow the summer height figures, as your lawn doesn’t go dormant. 

Keeping the grass blades longer in winter will create more insulation and keep the roots protected from the cold. It will also help keep weeds at bay and suppress their growth. It’s also important to use the catcher on your lawn mower as you don’t want grass clippings on the lawns. They break down more slowly at this time, increasing the risk of fungal disease infecting the lawn. Also, rake up fallen leaves so that the lawn gets as much light as possible, remembering to compost them and the clippings rather than throwing them out.

The winter months can bring harsh frost to the cold southern states of Australia, and it’s important to implement strategies to manage, and hopefully prevent, winterkill. Winterkill refers to grass getting damaged in extremely cold temperatures as a result of crown hydration or ice encasement. No grass is immune to winterkill, and you can see when it’s occurred as the blades of grass will be yellow and look dead. Winterkill will never kill grass – it will damage it, but it will almost always self-repair and bounce back when the weather warms up.

One important thing you can do is to stay off frosty lawns. If you walk across or mow the lawn, the blades will break off and this will cause even more damage. Wait until the frost has melted.