How to Prepare Your Lawn for a Southwest WA Summer

There’s a window, every year, between the last decent autumn rains and the real heat of a Southwest summer — and it’s the most important few weeks in the lawn calendar.

Get your lawn ready in that window and it’ll reward you all summer with thick, green grass that handles the heat and the foot traffic. Miss it, and you’ll spend December and January fighting fires — patchy dry spots, water repellent soil, stress-yellowing, and a lawn that’s burning through water without showing much for it.

Here’s what to do, and when.

Step 1 — Get Your Reticulation Running Right

Before you do anything else, turn your reticulation on and actually watch it run. This sounds obvious, but plenty of lawns go into summer with coverage gaps, blocked heads or broken risers that went unnoticed through winter.

Walk each zone and look for:

• Heads not spraying or spraying incorrectly — often blocked with debris or knocked out of alignment. Remove the head, flush it through, refit and test.
• Pooling or very heavy flow in one spot — usually a broken head that needs replacing.
• Dry patches in the coverage pattern — a section of lawn that’s consistently lighter in colour than the rest often has a head that’s not reaching it.

Once you’re confident the system is covering the lawn evenly, the next step is to know how much water it’s actually delivering. Place an empty container (an old ice cream tub works perfectly) on the lawn, run the sprinklers, and time how long it takes to collect 10mm of water. That time is your benchmark for a 10mm watering — the standard measure used in watering guides.

For detailed seasonal watering rates for both scheme water and bore water users, see our Watering Guide on the True Blue Turf website.

Step 2 — Apply a Wetting Agent Early

This is the step most Southwest WA lawn owners skip — and it’s the one that makes the biggest difference on sandy soils.

Sandy soil is naturally prone to becoming hydrophobic (water repellent) as it dries out. When this happens, water from your sprinklers runs straight off or channels down through the profile instead of spreading evenly through the root zone. The result is blotchy, dry patches even on a lawn that’s being watered regularly — and in summer, that means stress and die-back.

Applying a quality wetting agent in early spring — before the soil fully dries out — breaks down that water-repellent layer and helps moisture spread evenly and penetrate deeply. It’s not a cure for a broken retic system, but it dramatically improves the efficiency of every watering you do.

Two products worth looking at from the True Blue Turf store:

Bi-Agra

Bi-Agra is a dual-action product developed specifically for WA conditions — it both wets the soil and retains moisture at the root zone. It’s an easy hose-on application and a 2L bottle treats up to 150m². Research shows it remains effective for up to 12 months after application, making it excellent value for the start of summer.

Eco-Wet

Eco-Wet is a fast-acting, environmentally friendly soil wetter suited to waxy sands and water-repellent soils. It works quickly to restore water penetration and spread, and its organic certified polymer formula also improves soil structure over time. A 1L bottle treats up to 330m².

Both products are available from the True Blue Turf online store and our Bunbury store.

Step 3 — Fertilise Before the Heat Arrives

Spring is the ideal time to fertilise — the lawn is coming out of its slower winter period, actively growing, and ready to take up nutrients efficiently. Fertilising at this point builds the root strength and leaf density your lawn needs to handle summer stress.

The key rule: always fertilise when the leaf is dry, and water it in immediately afterwards. Never fertilise on a very hot day — heat combined with fertiliser can burn the leaf. As a general guide, fertilise at around 3kg per 100m² every 6–8 weeks through the growing season.

A product we recommend consistently is Eco Prime Emerald — a rock mineral fertiliser derived from natural volcanic and sedimentary deposits. It’s slow-release and non-leaching (important on sandy soils, where nutrients can wash through quickly), and it promotes healthy microbial activity in the soil that helps build a deep, strong root system. A lawn with deep roots is a lawn that handles summer heat.

Browse our full range of fertilisers in the True Blue Turf fertiliser collection.

Step 4 — Adjust Your Mowing Height

As summer approaches, the instinct is to mow shorter to keep things tidy. For most Southwest WA lawns, that instinct is worth resisting.

A slightly higher cut through summer acts as insulation — the leaf and thatch layer shade the soil and root zone, reducing moisture loss from evaporation and protecting roots from scorching. A lawn cut too short in a heatwave is working much harder to survive.

Recommended summer mowing heights:

• Kenda® Kikuyu: 15mm–30mm
• Sapphire® Soft Leaf Buffalo: 30mm–50mm

The other rule that matters just as much: never remove more than one-third of the leaf length in a single mow. If you’ve let the lawn get away on you between mows, bring it down gradually over a couple of sessions rather than scalping it in one go. Scalping a stressed summer lawn can set it back significantly and open the door to weeds.

Mow regularly, keep the clippings off the lawn after each mow, and leave the cut height where the lawn is comfortable.

Step 5 — Water Deeply, Not Often

Once summer is underway and the rains have stopped, the watering strategy that serves your lawn best on sandy soil is counter-intuitive to most people: water less frequently, but more deeply.

The goal is to encourage your lawn’s roots to chase moisture deeper into the soil profile, where it’s more stable and less subject to surface evaporation. A lawn with a shallow root system dries out quickly. One with roots travelling deep is dramatically more drought-resilient.

The way to build that deep root system is to let the lawn show the very first signs of wilting — a slight dullness or a bluish tinge to the leaf — and then give it a thorough, generous watering. Resist the temptation to run the sprinklers every day at low output; that keeps roots sitting near the surface where they’re most vulnerable.

As temperatures climb into the high 30s and 40s, you will need to increase frequency — deep watering less often works well in moderate summer heat, but extreme heat events require more regular watering to prevent damage.

Scheme water users: check your Water Corporation sprinkler roster and plan your watering days accordingly. Bore water users have more flexibility on timing, but the principle of deep, infrequent watering still applies.

Step 6 — Get on Top of Weeds Before Summer

Weeds are opportunistic — they move into any thinning, stressed or poorly maintained area faster than your lawn can recover. Summer stress can create exactly those conditions, so tackling weeds in spring, before the heat arrives, is the smart move.

For broadleaf weeds in buffalo lawns, Bow and Arrow is a highly effective post-emergent herbicide. For pre-emergent weed control across Kikuyu and other varieties, Spartan Herbicide stops weed seeds from germinating in the first place — applied in spring, it gives your lawn a head start heading into summer.

Not sure what weed you’re dealing with? Take a photo and email it to info@trueblueturf.com.au — we’re happy to identify it and point you to the right product.

Browse the full herbicides and weed control range in our store.

Is It Time for a New Lawn?

If your current lawn is past the point of preparation — bare patches, poor coverage, or a variety that’s struggled for years in your conditions — late spring is actually one of the best times in Southwest WA to lay fresh turf. The soil is warm, establishment is fast, and you’re going into summer with a head start rather than playing catch-up.

We grow both Kenda® Kikuyu and Sapphire® Soft Leaf Buffalo on our farm near Busselton, cut fresh to order and delivered across the Southwest — from Augusta to Perth and everywhere in between.

Want someone to handle the laying for you? We coordinate with a trusted local installer — visit our Turf Installation page for more information.

Prefer to do it yourself? Our How to Lay Turf guide walks you through every step.

Your Pre-Summer Lawn Checklist

A quick summary of everything to tick off before the heat arrives:

• Check and service your reticulation — coverage, direction, output
• Apply a wetting agent — Bi-Agra or Eco-Wet for sandy soils
• Fertilise — Eco Prime Emerald while the lawn is actively growing
• Raise your mowing height — and commit to the one-third rule
• Switch to deep, less frequent watering — build those roots down
• Control weeds — pre- and post-emergent before summer stress opens gaps
• Consider fresh turf — if your lawn needs more than preparation

Questions about any of this? Give us a call on (08) 9754 8873 or stop into our Bunbury store at 4/185 Blair Street, South Bunbury. We’re growers and lawn people — happy to talk through your specific situation.

Ready to Get Started?