Spring lawn care checklist for Australia and New Zealand

Come September, your lawn is basically stretching and yawning after a long winter — and what you do in the next few weeks decides whether it comes back thick and green or patchy and weedy. Spring lawn care is the single most important stretch of the whole year for warm-season grasses like buffalo, couch and kikuyu, because you're setting up the growth engine before the summer heat arrives. This checklist walks you through every job in order, from the first proper mow right through to fixing winter damage, with real timings, metric measurements and products you can actually grab at Bunnings or Mitre 10. Do them in roughly this sequence and by November you'll have a lawn the neighbours ask about.

Why timing matters more than effort in spring

Warm-season grasses are still semi-dormant in early September. Their roots aren't drinking much and the leaf isn't actively growing yet, so if you hammer the lawn with fertiliser or scalp it too early, you just stress it. The trick is to read the soil, not the calendar — wait until you see genuine green-up and daytime soil temperatures nudging past 15-18°C before the big jobs.

The key insight: Spring is about waking the lawn up gently and in the right order. Mow first, clear the old growth, feed once it's actively growing, then protect it. Rush the fertiliser and you feed the weeds instead of the grass.

The spring lawn care checklist, step by step

1. Give it a first proper mow and lower the height

Through winter you'll have kept the mower up high to protect the crown. As soon as you see consistent new growth (usually mid-to-late September), start dropping the cutting height gradually — no more than one-third of the leaf per mow. Lowering the height lets sunlight hit the base and warms the soil, which kicks growth along.

• Sharpen the blade first. A blunt blade tears the leaf and leaves a grey, frayed tip that browns off.
• Bag the first cut or two. You want the old, tired winter growth off the lawn, not mulched back in.
• Drop height in stages. Take a little each week rather than one brutal scalp.

2. Dethatch or scarify if the thatch is over 10mm

Push your fingers down to the soil. If there's a spongy brown mat more than about 10mm thick, that's thatch, and it stops water, air and fertiliser reaching the roots. Couch and kikuyu are the worst offenders. Rake it out vigorously with a spring-tine rake, or hire a powered scarifier from Kennards for a bigger lawn. Buffalo is more sensitive — give it a light rake only, never a hard scarify.

3. Aerate compacted areas

If your soil is hard as a brick — think pathways, kids' play zones, anywhere the ground has packed down over winter — aerate it. A garden fork pushed in 8-10cm every 10cm does the job on small patches; for bigger areas hire a coring aerator that pulls out little plugs. This lets the roots breathe and helps your spring fertilise and watering actually soak in.

4. Do the first spring fertilise

This is the big one. Once the lawn is actively growing (not before), feed it. A springtime fertiliser wants decent nitrogen to push leaf and colour, plus some potassium for root strength.

• Reach for something like Scotts Lawn Builder or Munns Professional Buffalo/All Purpose (roughly 20-25% N).
• Apply at the label rate, typically around 25-35g per square metre, using a spreader for even coverage.
• Water it in within 24 hours so it doesn't burn the leaf.
• Consider a follow-up liquid feed or a wetting agent 4-6 weeks later as things heat up.

5. Lay down a pre-emergent for summer weeds

Summer weeds like crabgrass, summergrass and crowsfoot germinate as the soil warms. A pre-emergent stops the seeds before they sprout — but it has to go down before germination, so early-to-mid spring is your window. Look for products with the active ingredient prodiamine or oxadiazon (e.g. Oxafert, which conveniently combines pre-emergent with fertiliser). Once weeds are up, a pre-emergent won't touch them, so don't leave it late.

6. Top-dress bare spots and level low patches

For thin or bare areas, level and top-dress with a quality washed sand/soil mix or a bagged lawn top-dressing. Spread a thin layer (no more than 10-15mm at a time so you don't smother the grass), rake it level, and either oversow with matching seed or let runners fill in. Keep it damp until it knits.

7. Ramp up watering as it warms

Winter watering is minimal, but as spring heats up your lawn needs more. Aim for deep, infrequent soaks — roughly 20-25mm per week including rain — rather than a daily sprinkle, so roots chase the moisture down. In NZ and southern Australia, many councils have watering restrictions kicking in by late spring, so check yours and consider watering in the early morning.

8. Fix winter damage

Cold, waterlogging and low light leave lawns thin, mossy or fungal-marked. Rake out dead patches, treat any moss (an iron-based moss killer works well and greens the lawn as a bonus), and oversow gaps once the soil is reliably above 15°C.

Month-by-month timing guide

Timings shift with your climate — coastal Queensland runs weeks ahead of Christchurch — but this is the general Sept–Nov rhythm:

Frequently asked questions

When should I fertilise my lawn in spring in Australia?

Wait until your lawn is actively growing and soil temperatures are consistently above 15-18°C, which is usually late September to October in most of the country. Feeding a still-dormant lawn just feeds the weeds.

Should I dethatch my buffalo lawn in spring?

Only lightly. Buffalo grows from above-ground runners rather than seed, so a hard scarify can set it back badly — give it a gentle rake to lift loose thatch and leave the powered scarifier for couch and kikuyu.

What is the best pre-emergent for summer weeds in NZ and Australia?

Look for products containing prodiamine or oxadiazon, and apply them in early to mid spring before the soil warms and weed seeds germinate. Combination products like Oxafert let you fertilise and prevent weeds in one pass.

How much should I water my lawn in spring?

Aim for around 20-25mm per week including rainfall, delivered as deep, infrequent soaks rather than daily light sprinkles, so the roots grow down and the lawn handles the coming summer heat.

How Lawnova builds this into a plan for your exact lawn

Lawnova takes your grass type, your region and even your local weather and turns this whole checklist into a dated to-do list — telling you the right week to fertilise, when your soil's warm enough to scarify, and when to get that pre-emergent down before the summer weeds beat you to it. No guessing, no generic advice, just the next job for your lawn. Get your free Lawnova plan and let's get your lawn thriving this spring.

Happy mowing — see you over the fence.