Should You Stop Fertilising Your Lawn in Winter?

Every year, millions of Australian lawn owners put their fertiliser away in May and do not touch it again until September. Most of them were told to. And if you have buffalo, kikuyu, or zoysia, stopping completely in winter is probably costing you colour, resilience, and weeks of spring recovery time. Here is what is actually going on and what to do instead.

The Advice to Stop Fertilising in Winter Comes From the Wrong Research

Most of the conventional wisdom around winter fertilising in Australia was built on research conducted on couch grass, which is the most studied turf variety in Australian sports turf management. Couch genuinely does not respond well to winter fertilising. It goes into a deeper dormancy than other warm season grasses and its ability to take up nutrients in cold conditions is poor.

The problem is that this couch specific finding was applied broadly to all warm season lawns. Millions of Australian homeowners with buffalo, kikuyu, and zoysia lawns were told to stop fertilising in winter based on research that was never conducted on their grass type.

There is Australian research that actually tested this properly. Ozbreed ran trials across multiple climate zones, including frost prone areas that recorded over 30 frosts in a single season and temperatures down to minus 3 degrees Celsius. The results were clear. Buffalo, kikuyu, and zoysia lawns that were fertilised through autumn and winter showed better green colour, better frost tolerance, and faster spring recovery than the unfertilised lawns sitting right next to them. Couch, however, showed no real benefit. Which is consistent with the older research that most of the stop fertilising advice was based on.

So here is the simple version. If you have couch, the old advice holds. Stop the nitrogen in winter and focus on a strong autumn feed. If you have buffalo, kikuyu, or zoysia, you have been following advice that was never meant for your grass type.

What Happens to Your Lawn in Winter Without Fertiliser

Here is what most people do not realise. Warm season grasses slow down in winter but the majority do not stop entirely, particularly in Queensland, coastal New South Wales, and Perth where soil temperatures rarely drop far enough to trigger true dormancy. A lawn that is slowing down is still a living plant. It is still consuming nutrients. And without anything coming in to replace them, those reserves quietly deplete all the way through winter.

Think about what that means for spring. The lawns that green up first and fastest in September are almost always the ones that were fed well through autumn and kept on a light maintenance program through winter. The ones that look thin and pale and take weeks to get going again are typically the ones that received nothing from May onwards. That is not a coincidence.

Colour loss through winter tells the same story. Most people assume the lawn is going brown purely because of cold. Often it is not. It is iron deficiency combined with nutrient depletion, and cold temperatures are just finishing the job. Iron drives chlorophyll production, which is what gives grass its colour. Applied to the leaf through the colder months, it holds colour noticeably better than doing nothing at all.

What to Apply in Winter and What to Avoid

Think of winter fertilising differently to what you do in spring and summer. You are not trying to push growth. You are trying to hold colour, maintain root health, and keep the nutrient bank topped up so the lawn has everything it needs to fire out of dormancy when temperatures rise. That shift in thinking changes which products you reach for.

What works well in winter

A foliar iron application is the standout for winter lawn care. Applied to the leaf, iron does not have to survive the soil chemistry that locks it up in many Australian soils, and it holds green colour through the coldest months. Apply Vivid monthly through winter at the reduced rate of 100ml per 100m2. Vivid contains nitrogen as well as iron, so the reduced winter rate matters. It keeps the iron coming without loading the lawn with nitrogen it cannot use in cold conditions.

In warmer zones where the lawn is still showing some growth, a conservative liquid fertiliser application is worthwhile. Keep the nitrogen rate at roughly half what you would use in summer. You are feeding the plant, not trying to make it grow. In cooler zones, keep the nitrogen minimal and focus on iron and potassium, which builds root strength and cold tolerance without the risk.

What to avoid in winter

Heavy nitrogen at summer rates in cooler zones is the one thing that can genuinely hurt a lawn in winter. It pushes soft, water heavy leaf tissue that frost and cold damage easily. This is the real and legitimate concern behind the stop fertilising advice. But reducing the rate is the answer, not stopping altogether.

Granular fertilisers are worth being honest about here. In warmer months they work well. The issue in winter is that granular products rely on soil biology to break down and release nutrients, and soil microbial activity slows significantly as temperatures drop. A granular product applied in winter in a cool climate zone can sit largely inactive until the soil warms again in spring. Liquid fertilisers are already in a form the plant can absorb and do not depend on soil biology to deliver results, which is why they perform better specifically in the cooler months.

The Winter Program Worth Following

For buffalo, kikuyu, and zoysia lawns across most of Australia, here is what a practical winter program looks like.

Start with Soak before anything else. Winter soil is often still hydrophobic from summer and products applied to hydrophobic soil run off before reaching the roots. Soak fixes that and makes everything else you apply actually work.

Apply Vivid monthly through winter at 100ml per 100m2. This is the part of the program worth holding onto regardless of your location, and the reduced rate is what makes it suitable for cold conditions.

If you are in Queensland, northern New South Wales, or coastal areas where the lawn is still showing growth, add Surge at roughly half your summer rate. Keep it conservative. Maintenance, not stimulation.

If you have couch, hold the nitrogen but keep using Vivid at the winter rate for colour. Couch will lose some colour in winter regardless of what you apply in cooler zones. Accept that and focus your energy on a strong autumn feed and a well timed spring application when growth returns.

Complete the Program

Colour and nutrition through winter are 2 of the 3 things your lawn needs to come out of winter ahead of where it went in. The third is root health. A lawn with deep, strong roots handles cold better, holds colour longer, and recovers faster in spring than a lawn with shallow roots regardless of what you spray on top of it.

The Full Routine Bundle includes all 5 Turf and Surf products at a reduced price, including Vital, our root stimulator that drives deep root development and keeps the root system strong through winter, and Base, our kelp soil conditioner that improves the soil environment roots grow in. If your goal is to come out of winter with the best lawn on the street, that work starts now, not in September.

Read the 5-step program guide to see exactly how all the products work together through every season.

Frequently Asked Questions

Should I stop fertilising my lawn in winter?

It depends on your grass type. Couch lawns benefit from stopping nitrogen fertilising in winter and focusing on a strong autumn feed instead. Buffalo, kikuyu, and zoysia lawns in most Australian climate zones benefit from continued light fertilising through winter, particularly iron applications for colour and conservative nitrogen in warmer zones where the lawn is still showing some growth. The blanket advice to stop fertilising in winter was built on couch research and does not apply to all grass types.

My lawn goes brown every winter. Is there anything I can do?

Some colour loss in winter is normal for warm season grasses, particularly couch. However, rapid or severe colour loss is often iron deficiency rather than dormancy alone. Applying a foliar iron product like Vivid at the reduced winter rate can maintain colour through winter. If colour loss is severe and does not respond, the lawn is likely in deeper dormancy and will recover naturally when soil temperatures rise in spring.

Is it safe to apply iron to my lawn in winter?

Yes. Iron supports chlorophyll production, which is responsible for green colour, and does not drive leaf growth the way nitrogen does. Vivid contains both, so use the reduced 100ml per 100m2 winter rate through May, June and July. That keeps the iron coming without pushing the soft new growth that cold temperatures can damage.

What is the difference between winter dormancy and iron deficiency?

Apply a foliar iron product and watch for a response over the next 5 to 7 days. If colour returns noticeably, the lawn was iron deficient rather than dormant. If there is no visible response, the colour loss is driven by temperature and will not reverse until soil temperatures rise in spring. This is a useful diagnostic because iron at the winter rate is safe to apply in either scenario, so there is no risk in testing it.

When should I start fertilising again after winter?

For warm season grasses, the signal to return to full fertilising is visible new growth, not the calendar date. In Queensland and northern New South Wales this often happens in August. In Sydney and Perth, typically September. In Melbourne and cooler zones, late September to October. Watch the lawn rather than the calendar. When you see active new growth starting, the lawn is ready to receive and use a full application.