When to fertilise your lawn: a season-by-season schedule

If you've ever stood in the shed holding a bag of fertiliser wondering whether now is the right moment, you're in good company. The truth is that knowing when to fertilise your lawn matters far more than which fancy product you pick. Feed at the right time and cheap fertiliser works wonders. Feed at the wrong time and the best bag on the shelf just washes away or, worse, stresses your grass. This guide gives you a clear, season-by-season schedule for both warm-season and cool-season lawns, so you can stop guessing and start feeding with confidence.

The golden rule: feed when the grass is growing

Here's the one idea that makes everything else fall into place: fertilise your lawn when it is actively growing, not when it's dormant.

Fertiliser is food. Food is only useful to something that's awake and hungry. When your grass is putting out fresh green growth, it can take up nutrients and turn them into thick, healthy turf. When it's dormant — brown, sluggish, or hunkered down against heat or cold — it simply can't use what you give it. That unused fertiliser doesn't sit patiently waiting; it leaches away, feeds weeds, or burns roots.

The key insight: Don't feed by the calendar, feed by the grass. Green and growing means hungry. Brown and dormant means leave it alone.

This is also why the same advice works whether you're in the northern or southern hemisphere. Forget "feed in March" — watch what the lawn is actually doing.

Reading growth as your cue

You don't need a lab to tell if your lawn is growing. Look for the signs:

• You're mowing again. If you've had to get the mower out and you're taking off a decent clipping, the grass is active and ready to eat.
• Fresh colour. New growth comes in a brighter, lighter green at the tips.
• Soil has warmed or cooled into range. Grass wakes up when soil temperatures sit in its comfort zone, which lags a few weeks behind the air.
• It's recovering, not just surviving. A lawn bouncing back from stress is a good candidate. A lawn barely holding on is not.

The big split: warm-season vs cool-season grasses

Almost all lawn timing comes down to which family your grass belongs to. Get this right and the schedule sorts itself out.

Warm-season grasses

These love heat and grow hardest through the warm months. Think couch (Bermuda), kikuyu, buffalo (St. Augustine), zoysia, and paspalum. They green up as things warm, romp away through summer, then slow right down and often go brown and dormant once it turns cold.

• Feed them: through the warm growing season, from spring once they've greened up, through into summer.
• Ease off: in late summer to early autumn.
• Stop: through autumn and winter while they're dormant. Feeding a dormant warm-season lawn is money down the drain.

Cool-season grasses

These prefer mild conditions and can struggle in extreme heat. Think fescue, ryegrass, Kentucky bluegrass, and bent. They grow strongly in spring and autumn, and tend to sulk during the hottest part of summer.

• Feed them: in spring as they take off, and — most importantly — in autumn.
• Go light: through the peak of summer heat, when they're stressed rather than thriving.
• Autumn is the big one. A good autumn feed builds root reserves that carry the lawn through winter and give it a flying start next spring.

How many times a year should you fertilise?

For most home lawns, two to four feeds a year is plenty. More isn't better; it just encourages soft, disease-prone growth and more mowing.

• A relaxed lawn: two well-timed feeds a year will keep it healthy. For warm-season, that's spring and mid-summer. For cool-season, that's spring and autumn.
• A showpiece lawn: three to four lighter feeds spread across the growing season give steadier colour without a feast-then-famine cycle.
• Split the difference. Smaller, more frequent doses beat one big hit — the grass uses the nutrients as it goes, rather than getting a shock it can't absorb.

Your season-by-season feeding schedule

Frame each column by what the grass is doing rather than a month, so it works wherever you live.

Use it as a framework, not gospel. Your local climate, soil, and the particular season all nudge these windows around — which is exactly why watching the grass beats following dates.

Why timing beats product every time

It's tempting to believe the answer is in the bag. But a lawn that's fed at the right moment with a basic balanced fertiliser will always beat a lawn given a premium product at the wrong time.

• Right time, wrong product: the grass is hungry and takes up whatever you give it. It'll green up and thicken regardless.
• Wrong time, right product: the grass can't use it. It leaches into waterways, feeds weeds, or scorches roots.

Save your energy for getting the timing right, and don't lose sleep over choosing between two decent products.

When NOT to fertilise

Just as important as knowing when to feed is knowing when to hold off. Skip the fertiliser when:

• The lawn is dormant. Brown warm-season grass in winter can't use it. Wait for green-up.
• The lawn is stressed. Drought, disease, or heat-stressed grass needs recovery, not a growth push it can't sustain.
• There's frost about. Feeding into frosty conditions can damage tender new growth. Wait until the frost risk has passed.
• The soil is bone dry. Fertiliser needs moisture to work and to avoid burning. Water first, or wait for rain.
• Rain isn't coming and you can't water. Which brings us to the last step.

Always water it in

After you spread fertiliser, water it in with a good soaking unless steady rain is on the way. Watering moves the granules off the leaf and down to the roots where they're needed, and it dramatically reduces the risk of burning your lawn. A dry fertiliser sitting on dry blades in the sun is asking for scorch marks. Ten minutes with the sprinkler saves a lot of grief.

Frequently asked questions

What month should I fertilise my lawn?

There's no universal month, because it depends on your grass type and climate. Feed warm-season grass through spring and summer once it's green and growing, and feed cool-season grass in spring and autumn. Watch for regular mowing as your signal.

Can you fertilise a lawn in winter?

Generally no. Warm-season lawns are dormant in winter and can't use it, and feeding into frost can damage growth. Cool-season lawns in very mild climates may take a light feed if they're still actively growing.

How soon after fertilising should I water?

Water it in the same day, ideally straight after applying, unless steady rain is forecast. This carries the nutrients to the roots and protects the grass from fertiliser burn.

How often should I fertilise my lawn?

Two to four times a year suits most home lawns. Two well-timed feeds keep a lawn healthy; three or four lighter feeds give a showpiece lawn steadier colour without overdoing it.

Will fertilising a stressed or brown lawn help it recover?

Usually not — it can make things worse. A stressed lawn needs water and time to recover first; fertiliser pushes growth the grass can't support and adds to the stress. Fix the underlying problem, then feed once it's growing again.

How Lawnova takes the guesswork out of feeding

The hardest part of all this is knowing what your grass is doing right now, in your garden. That's exactly what Lawnova is built for. Tell us your grass type and location, and we'll watch the seasons for you and nudge you when it's genuinely time to feed — not a day too early, not a day too late. No more guessing in the shed, no more wasted fertiliser.

Get your free Lawnova plan

Feed the grass when it's hungry, water it in, and the green will take care of itself.