Key facts

Topdressing vs levelling vs re-turfing: what’s the difference?

• Topdressing is spreading a thin layer of sand or soil over an existing lawn so the grass grows up through it. It smooths small hollows and helps manage thatch, but it can’t move much soil.
• Levelling means reshaping the ground itself: cutting high spots, filling low areas and setting falls away from the house. On an existing lawn, that usually means lifting the turf first.
• Re-turfing is laying new turf on a prepared, level base. When a lawn is badly uneven and also thin or weedy, it is often the quicker, more reliable fix.

Why lawns get bumpy in Brisbane and on the Sunshine Coast

• Settling on new builds. Fill, service trenches and backfill around slabs keep settling for months or years, a common story on newer estates such as North Lakes, Springfield, Logan and Caloundra/Aura.
• Soil type. Many Brisbane suburbs sit on clay soils that shrink and swell with the seasons. Much of the coastal Sunshine Coast is sandier, which drains well but can wash out in heavy rain.
• Storms and runoff. Summer downpours scour soil from slopes and deposit it in low spots.
• Mowing and wear. Scalping, wheel ruts, worn paths, digging dogs and rotting tree roots all leave an uneven surface.
• Pests. Grub damage can leave soft, sunken patches. Treat the cause before filling.

If the low spots stay wet for days after rain, the problem is drainage, not just level, and filling the hollow won’t fix it. Our guide to fixing a waterlogged lawn covers that first, and our site and soil preparation work includes drainage correction.

How bad is it? Measure before you buy anything

Lay a straight board or long spirit level (2–3 m is ideal) across the problem area and measure the biggest gap under it with a ruler. Check in a few directions and mark the worst spots. Then use this table to pick your route.

When to topdress in Brisbane and the Sunshine Coast

Topdress when the grass is growing strongly enough to push back through the new layer. In South East Queensland that is roughly September to March, and spring and early summer are ideal. In winter, warm-season grasses slow down and sand can sit on the leaf for weeks, shading it and inviting weeds. Our year-round lawn care plan shows where topdressing fits with aerating and fertilising.

• Start once the lawn is green and needs mowing regularly again, usually from September.
• Leave 4–6 weeks between passes, so each layer is grown through before the next.
• Check the forecast. Fresh, loose topdressing washes easily in a summer storm, so aim for a few settled days afterwards. The Bureau of Meteorology’s warnings and alerts page is worth a look before you start.

Choosing the right topdressing material

• Washed sand (sold as topdressing sand or washed river sand) is the standard choice for top dressing a lawn with sand. It spreads easily, drains well and doesn’t set hard.
• Sandy loam or a lawn topdressing mix (sand with some soil or organic matter) holds a little more moisture and nutrients, which can suit very sandy Sunshine Coast soils.
• Match the material to your soil where you can. A very different material can create layers that block water. On Brisbane clay, stick to sand or a sandy mix.

Your local landscape supplier will stock topdressing sand and lawn mixes. What to avoid: brickies’ sand (it contains clay and can set hard and drain poorly), heavy clay topsoil, and unscreened fill with rocks or weed seed.

How much topdressing do I need?

Use this formula: area (m²) × depth (m) = volume (m³). A 5 mm layer is 0.005 m and a 10 mm layer is 0.01 m. If you haven’t measured the lawn yet, follow our guide on how to measure your lawn.

These are for an even layer over the whole area; filling hollows only takes less. Round up a little, and check whether your supplier sells by the cubic metre or the tonne.

Topdressing your lawn, step by step

1. Mow a notch lower than usual, without scalping, and remove the clippings.
2. Open up the surface. If the lawn is spongy or compacted, dethatch lightly and core-aerate first.
3. Tip the sand in small piles across the area rather than one big heap.
4. Spread and level with the back of a landscape rake or a levelling rake (lute), working it into the hollows and pulling it off the high spots.
5. Keep the leaf tips showing. If you can’t see green through the layer, it’s too deep. Brush or rake the excess away.
6. Water it in thoroughly to settle the material around the leaves.
7. Repeat after 4–6 weeks for deeper hollows, once the grass has grown through.

Rather not do it yourself? Top dressing and aeration are among our lawn care services, so ask us for a quote.

Fixing a deep dip (30–50 mm): lift, fill and relay

For a dip too deep to fill from above, cut an H or a cross through the turf with a sharp spade, slide the spade under and peel the flaps back. Fill underneath with a sandy soil, firm it down, and add a little extra to allow for settling. Lay the turf back, press it in, check the level with your straightedge and water well.

Knocking down high spots

Don’t try to mow a hump away; scalping just weakens the grass. Lift the turf on the high spot the same way, scrape out the excess soil, relay the turf and water it. Where a hump is caused by a tree root, get advice before cutting it.

Topdressing by grass type

• Sir Walter buffalo: top dressing buffalo grass works if you keep it light. Buffalo has broad leaves and thick runners, so it copes with thin layers but not heavy ones. Keep each pass to about 5 mm, never bury the leaf, and use it mainly to fix hollows rather than as a routine job.
• Empire Zoysia: zoysia is dense and slower growing, so it takes longer to recover. Use thin layers, give it longer between passes, and topdress mainly to fix levels.
• Wintergreen couch: couch is the most forgiving. Its fast runners grow through sand quickly, which is why couch sports fields and greens are topdressed regularly. A spring aerate and topdress freshens it up well.

Will existing grass grow through topdressing?

Yes, as long as the layer is thin and the grass is actively growing. Keep each application to 10 mm or less with some leaf still visible. In warm weather a healthy lawn usually pushes through within one to three weeks. Thick layers, especially of heavy soil, block light and air and can kill the grass, which is why deep hollows need several passes or lifting and relaying.

When to skip topdressing and re-turf instead

Topdressing smooths a healthy lawn. It won’t rescue a lawn that is failing. Re-turfing is usually the better investment when:

• the lawn needs more than a couple of passes and is thin, patchy or weedy
• large areas are more than 50 mm out of level, or fall towards the house
• the existing grass is the wrong variety for the spot, such as a sun-loving couch in heavy shade
• you want a finished lawn this season rather than over several months

New turf needs a properly levelled, well-prepared base, which our site and soil preparation and turf installation teams can handle. See turf underlay and soil and laying turf over existing grass. Work out how much you need with the turf calculator, then choose from our three varieties, all cut to order at our Woodford farm: Wintergreen couch turf at $7.00/m², and Sir Walter buffalo turf and Empire Zoysia turf at $15.50/m².

How the pros level it

On sports fields, levels are set with laser-guided equipment before any turf goes down. At the Samford Parklands football precinct, the subgrade was laser-trimmed to ±10 mm before the growing medium and turf went down, and the fields were then maintained with regular sand topdressing. At the Bob Brock soccer field, a 100 mm sand layer was laser graded and rolled before Wintergreen couch was laid. At the Metricon Stadium training field at Carrara, a light topdressing after the drainage trenches were backfilled brought the surface back to level. The principle is the same at home: get the base right, then fine-tune with thin topdressing. See our commercial and sports turf work for more.

Frequently asked questions

Too bumpy to fix yourself? Send us your measurements and a few photos through our free quote form. We can advise whether it needs topdressing, levelling and site preparation, or new turf, across Brisbane and the Sunshine Coast.

Key facts

Signs your lawn has a drainage problem

Any lawn is soft for a day after a big storm. A drainage problem is the same patch, storm after storm, still wet when the rest of the yard has dried. Look for:

• puddles that are still there 24 hours or more after rain
• ground that squelches underfoot, or footprints that fill with water
• thin, yellowing grass and shallow roots that lift out easily
• moss, algae or sedges moving in
• a sour, rotten-egg smell when you dig

Waterlogged or just overwatered?

Turn the irrigation off for a dry week. If the patch dries out, cut back your run times. If it stays wet with no rain and no sprinklers, water is getting in from elsewhere (a leaking pipe, a neighbour or groundwater) or has nowhere to go.

Do the 24-hour drainage test

This tells you whether the problem is at the surface or deeper. Do it in the worst spot, and in a good spot to compare.

1. Dig a hole about 300 mm deep and 300 mm wide.
2. Fill it with water and let it drain away completely. This wets the surrounding soil.
3. Fill it again to the top and note the time.
4. Check it after 1 hour, after 4 hours and the next morning.

Two more checks: push a long screwdriver into the lawn (if it stops hard at 50 to 100 mm, you have compaction or a clay layer), and next time it pours, watch where the water comes from and where it goes.

What’s causing it? Brisbane and Sunshine Coast soils

Reactive and sodic clay

Much of Brisbane, Ipswich and Logan sits on heavy clay, and some of it is sodic. The Queensland Government explains that soil sodicity causes surface crusting and sealing and slows water moving through the soil.

Builder’s fill on new estates

On new estates such as North Lakes, Ripley, Yarrabilba and Palmview, yards are often compacted clay fill with a skim of topsoil and little fall. Service trenches settle, and water ends up against the slab or along the fence.

Coastal sand over clay

Sandy Sunshine Coast soils usually drain fast. Where sand sits over clay, or the water table is high in low-lying areas, the sand fills like a sponge and stays wet.

Quick fixes for mild waterlogging

If your test hole emptied by the next day, start here.

• Stay off it while it’s wet. Traffic on saturated soil compacts it further.
• Core aerate, then top-dress. Hollow tines pull out plugs of soil; brush washed sand or sandy loam into the holes so they stay open. Do it while the grass is growing, spring to early autumn in SEQ.
• Gypsum for sodic clay. Gypsum helps only dispersive clay, not compaction or low spots. Drop a dry soil crumb into rainwater: if a cloudy halo forms, try gypsum at the rate on the bag.
• Fill shallow low spots. Top-dress dips a little at a time, keeping leaf tips showing.

Does sand help lawn drainage?

Yes, but only when it gets into the soil. Sand brushed into aeration holes creates drainage channels. A layer spread over clay without aerating does little and can hold water on top of the clay. Avoid brickies’ sand, which contains clay.

Permanent lawn drainage solutions

If water was still in the hole after 24 hours, change the shape of the ground or give the water somewhere to go.

• Regrade to a fall. Shape the subsoil so water runs away from the house. We work to about 1% (10 mm per metre) on sports fields, a sensible target for a backyard too. Keep the fall running away from the slab, and check it against your builder’s or council’s approved levels.
• Ag pipe or French drains. This is what most people mean by drainage under lawn. A simple lawn drainage system of slotted pipe in a socked, gravel-filled trench carries water away, provided the trench has a fall and discharges somewhere lawful.
• Spoon drains and swales. A shallow turfed dish along a boundary or slope catches surface water, handy where runoff comes from next door.
• Soakwells in clay: usually not. In heavy clay a soakwell just fills up and stays full.

Plumber or turf team?

Shaping, decompacting, subsurface drains within the lawn and returfing are landscape work. Connecting to a stormwater pit, kerb outlet or downpipes is not. In Queensland, drainage work other than unregulated work needs a licensed plumber or drainer, and your water must go to a lawful point of discharge. Your council can tell you where that is. Sunshine Coast Council notes it may get involved if water is concentrated onto a neighbouring property, so don’t push your problem over the fence.

We use the same principles on sports fields. At Genesis College, Bray Park, we built swale drains with subsurface drains along their toe. At Clive Berghofer Stadium, Toowoomba, we reused the red clay site soil, ripped it, added gypsum and lime, and laser-graded it to a 1% fall to swale drains. At Sheldon College, subsurface drains sit on a 1% fall, with gravel bands connecting them to the surface. Our commercial and sports turf construction page has more of that work.

Fix drainage first, then returf

New turf on the same bad base fails the same way, usually in its first wet summer. Work in this order:

1. Find the cause with the 24-hour test and a storm check.
2. Remove the old lawn and any weeds.
3. Rip or cultivate compacted subsoil, and work in gypsum if the clay is sodic.
4. Shape the subgrade to a fall, away from the house.
5. Install ag drains or swales, and have a licensed plumber make any stormwater connections.
6. Spread 100 to 150 mm of sandy loam underlay, following the same fall.
7. Level, lightly firm, then lay and water in the turf, or have our team handle the turf installation.

This is what our site and soil preparation service covers: levelling, drainage correction such as subsurface drainage and contouring, and soil conditioning before the turf goes down.

Best turf for wet or poorly drained SEQ yards

No lawn grass likes sitting in water, and no variety rescues a yard that floods. Once drainage is fixed, match the grass to the light and use. Our turf varieties page compares every lawn we grow.

All three are cut to order at our Woodford farm and delivered across Brisbane and the Sunshine Coast. Once you have measured your lawn, the turf calculator gives you the square metres and the price.

What drives the cost of fixing drainage

We price drainage work after seeing the site. The main drivers are:

• the area, and how much soil must be moved or imported to create a fall
• machinery access
• the length of drain, and how far it is to a lawful discharge point
• any plumbing connections, which are a separate licensed trade
• underlay volume, and the turf variety you choose

Doing drainage, soil and turf as one job beats returfing twice. For a whole yard, a front and backyard turf package bundles the site assessment, turf and installation.

Timing around the Queensland wet season

SEQ’s heaviest rain usually falls from December to March. August to October is usually the driest time, and storms tend to arrive from late spring, so that is the best window for drainage work: the ground is workable and new turf has a head start before the wet. Wait for summer and you’re working wet clay that smears, with new turf that can wash out. For the turf itself, see the best time to lay turf in South East Queensland.

A note on artificial grass

Artificial grass still needs a free-draining base and a fall, because water drains through the backing into whatever is underneath. We grow and lay natural turf only, but the basics (find the cause, create a fall, discharge lawfully) apply to both.

Frequently asked questions

Fix it once

If your lawn floods every wet season, returfing alone won’t fix it. We’ve grown turf at Woodford since 1994, and we can assess your drainage, rebuild the soil profile and lay fresh, farm-grown turf in one job. Read about our site and soil preparation, see our lawn care services for ongoing care, or ask for a free quote.

Key facts: armyworm, curl grubs and African black beetle

Is it armyworm or lawn grubs? A 60-second checklist

Lots of things turn a Queensland lawn brown, including dry spells, fungal disease, dog urine, scalping with the mower and poor drainage. Our guide to grubs, diseases and weeds in Queensland lawns covers the other causes. Check these signs before you buy anything.

• The damage moves. Armyworm damage spreads across the lawn over a few days, with a clear line between chewed and healthy grass. The healthy side is where they are feeding next.
• The leaf is chewed, not dried. Armyworm leaves ragged, chewed blades and bare stems. Drought stress leaves whole blades that are rolled and straw-coloured.
• The turf lifts like carpet. If you can peel the grass back by hand and there are almost no roots, suspect curl grubs or African black beetle larvae.

The soapy water test (for armyworm and beetles)

This is the quickest way to confirm armyworm. Do it late in the afternoon, when the caterpillars are most active.

1. Stir a good squirt of dishwashing liquid into a full bucket of water. The exact amount isn’t critical.
2. Pour it slowly over about one square metre at the edge of the damage, where brown meets green.
3. Wait 5–10 minutes and watch the surface.
4. Armyworm caterpillars and black beetles come to the top. A few is normal; a lot means an active infestation.

If you’d rather not use soap, lay a wet hessian bag or old towel on the lawn overnight and lift it early in the morning. Caterpillars and beetles often shelter underneath.

Lawn armyworm vs fall armyworm: why Google shows farm news

Most “armyworm” news is about fall armyworm (Spodoptera frugiperda), an exotic pest that reached the Australian mainland in 2020 and mainly attacks crops such as maize and sorghum, according to Business Queensland. The caterpillar in Brisbane and Sunshine Coast lawns is almost always lawn armyworm (Spodoptera mauritia), a native species.

Curl grubs and African black beetle: signs, tests and timing in SEQ

Lawn grubs feed in the root zone, so the damage stays hidden until the grass dies. Suspect them if brown patches don’t green up after watering, the turf feels spongy, or birds and bandicoots keep digging the same area.

The dig test

The soap test often won’t bring grubs up. Instead, cut three sides of a square about 30cm × 30cm at the edge of a dead patch with a spade. Fold the turf back and look in the top 5–10cm of soil for creamy-white grubs curled into a C-shape. Check a few squares across the lawn. If you keep finding several in each square and the turf lifts easily, grubs are the likely cause. African black beetle adults show up in a soap test or under wet hessian, and their larvae look like small curl grubs.

When to treat lawn grubs

In South East Queensland, curl grub damage usually shows through summer and into autumn, after the beetles have laid their eggs in late spring and early summer. Grub products generally work best on young larvae near the surface, so treat as soon as you confirm grubs in early to mid summer rather than waiting until autumn. Check the label for the timing it recommends; some products are designed to go on before the eggs hatch.

When is armyworm season in SEQ?

Business Queensland’s native armyworm page notes that armyworm moths generally fly in September and October, and that lawn armyworm can complete two to three generations over the warm months. In South East Queensland, that means:

• September–October: moths generally fly and lay eggs. This is the time to watch and to prevent.
• November–April: caterpillars feed. Outbreaks often follow warm, humid weather and summer storms, and the damage can appear almost overnight.

For what to do in each season, see our year-round lawn care plan.

How to treat lawn armyworm and lawn grubs

Timing and preparation

• Armyworm: treat in the late afternoon or early evening. The caterpillars feed from dusk, so the product is fresh on the leaf when they come out. Don’t mow just before you treat, because the leaf holds the product. Follow the label on whether to water it in.
• Lawn grubs: the product has to reach the root zone. Most grub products say to water in well after you apply them. Watering the lawn a day beforehand helps the product soak in rather than run off.
• Treat the green edge too. The pests are in the grass they haven’t eaten yet, so treat a metre or two into the healthy lawn.

Active ingredients to look for on the label

We don’t recommend brands. Read the active ingredient and check that the label lists your pest and use on home lawns. The label is the law: use the rate, method and re-application interval it gives, and wear what it tells you to wear. Actives you’ll commonly see on Australian lawn insecticide labels include:

• Chlorantraniliprole: labelled on some products for armyworm, curl grubs and African black beetle.
• Bifenthrin: labelled on some products for surface pests such as armyworm and black beetle. It is toxic to fish and aquatic life.
• Bacillus thuringiensis (Bt) and spinosad: biological options for caterpillars. They work best on young caterpillars.
• Beneficial nematodes: Business Queensland notes that the nematode Steinernema carpocapsae is sold commercially for use in turf.

Pets, kids and waterways

Keep pets and children off treated areas for as long as the label says, and at least until the product has dried or been watered in. Never apply before heavy rain or spray into gutters and drains, which run to local creeks and the bay.

Can grass recover from armyworm or grubs?

Often, yes. The question that matters is whether the runners and crowns are still alive. Armyworm eats leaf, so a lawn can look dead while the runners (stolons) underneath are fine. Grubs eat roots, so the damage is deeper and recovery is slower.

The tug test and green-node check

1. Tug: grab a handful of the brown grass and pull gently. If it stays anchored, the roots are working. If it comes away with no roots, grubs have been at it.
2. Scratch: find a runner and scrape the outer layer with your thumbnail. Green or white and firm inside means alive. Brown, dry and brittle means dead.
3. Check the nodes: look at the joints along the runner. Plump, green nodes will shoot new leaf.
4. Sample widely: check the middle, the edges and a few spots across the lawn to judge how much is dead.

Wintergreen couch, Sir Walter buffalo and Empire Zoysia are all warm-season runner grasses, so they can regrow from live runners in the warm months. No variety is immune to armyworm or grubs, although Empire Zoysia is less susceptible to lawn grubs. Recovery is much faster from October to March than in winter, and a lawn damaged in late autumn may sit brown until spring.

A 7-step recovery plan

1. Confirm the pests are gone. Re-test with soap or a dig 7–10 days after treatment.
2. Rake out loose dead leaf lightly so light and water reach the runners. Don’t scalp the lawn or dethatch it hard.
3. Apply a lawn fertiliser at the label rate and water it in. Nitrogen and water drive regrowth.
4. Water deeply and less often, rather than a light sprinkle every day, so the roots grow down.
5. Raise the mower one notch and leave it there until the lawn has thickened up.
6. Keep foot traffic, dogs and cars off the weakest areas while they regrow.
7. Watch for a second wave. Armyworm can have more than one generation a season, so re-check with a soap test every couple of weeks through summer.

For routine care once it’s back, see our lawn care overview and seasonal turf care guide.

Recover or re-turf? A decision table

Once the pests are under control, use this as a rough guide. As a rule of thumb, if more than about a third of the runners in an area are dead, re-turfing that area is usually quicker and more reliable than waiting.

Lawn looks dead? Get it checked. If you can’t tell whether it will come back, our lawn care team can help you decide whether to nurse it back or replace it. Replacing patches? Work out your m² with the turf calculator, then order turf delivery to Brisbane or the Sunshine Coast.

How to patch re-turf after pest damage

1. Make sure the pest is controlled first. Laying new turf into an active infestation just feeds the next generation.
2. Cut out the dead turf with a spade or turf cutter, with straight edges, down to the soil.
3. Loosen the soil, add a little turf underlay if it’s poor, and level it so the new turf sits flush with the old lawn. Our site and soil preparation page explains the basics. Shallow dips in turf that survived can be top-dressed and levelled instead.
4. Measure each patch (length × width) and add about 5% for cutting in. The turf calculator does the maths.
5. Lay the turf the day it arrives, butt the joints tight, and water it straight away. Then keep it moist until it roots down.

Match the variety to what’s already there. Wintergreen couch is $7.00/m², and Sir Walter buffalo and Empire Zoysia are $15.50/m².

Preventing armyworm and lawn grubs next season

• Spring is the window. Armyworm moths generally fly in September and October, and scarab beetles lay eggs from late spring. If your lawn was hit last season, this is when a preventative product labelled for armyworm and grubs is worth considering.
• Watch the lights. Lots of moths around outdoor lights in spring, or warm, humid weeks after storms, are your cue to start soap tests every week or two.
• Grow a strong lawn. Mow at the right height, fertilise in the growing season and water deeply rather than often. Deep roots handle pest damage far better.

Frequently asked questions

Need new turf after pest damage?

If a patch or full re-turf is the answer, request a quote for turf delivered across Brisbane and the Sunshine Coast, or ask about turf installation if you’d rather have it laid for you.