This guide covers exactly how to plant native trees in Perth sand — and keep them alive through their first summer. Perth’s sandy soil kills more native trees than drought does. Not because the trees cannot handle it — they evolved here. Because most people plant into raw sand without preparing it first. Here is everything you need to know to give your $150 Treebate tree the best possible start.
The $150 Treebate rebate lands in your account within seven business days of a successful ServiceWA claim. The tree you planted to earn it could be dead within seven weeks if you skip the soil preparation step.
This is not an exaggeration. Perth’s predominantly sandy soils — specifically the Bassendean sands that cover most of the Swan Coastal Plain residential area — are hydrophobic. Water repellent. When dry, water beads on the surface and runs off rather than penetrating to the root zone. A newly planted tree sitting in hydrophobic sand in a Perth summer is not a tree in soil. It is a tree in a dry bucket.
The good news: the fix is straightforward, inexpensive, and only needs to be done once at planting time. Do it right and your tree will establish in its first winter and look after itself from the second summer onward.
Understanding Perth Soil — Know What You Are Working With
The Swan Coastal Plain runs in parallel bands from the coast inland to the Darling Scarp. Soil type changes significantly as you move east, and knowing which band your garden sits in shapes every planting decision.
Coastal Spearwood Sands — Western Suburbs, Coastal Strip
Deep white to cream sand containing fine-grained limestone. Highly alkaline (pH up to 9 in some areas). Excellent drainage — sometimes too excellent. Very low nutrient and water retention. Salt-laden coastal winds add an additional stress factor for new plantings.
Bassendean Sands — Most of Perth Metro
The dominant soil type across the majority of Perth’s residential suburbs. Pale grey to yellow sand. Described accurately as “gutless” — very low organic matter, very poor water and nutrient retention, and highly water repellent when dry. This is what most Perth residents are working with.
Spearwood Dunes — Northern and Southern Suburbs
Sandy soils with variable nutrient content depending on proximity to the coast. Similar challenges to Bassendean sands with some variation in water retention.
Pinjarra Plain Alluvial Soils — Eastern Suburbs, River Corridors
Loamy alluvial material deposited by rivers from the Darling Scarp. Significantly better fertility and water retention than coastal sands. Some areas become seasonally wet. The easiest soils in Perth to plant into — though waterlogging risk must be managed for species requiring good drainage.
Limestone Soils — Many Southern Suburbs
Calcareous sands over limestone. Alkaline. Free-draining. Important note: Proteaceae species including Banksia and Hakea have documented sensitivity to high calcium levels in combination with phosphorus — an additional reason never to fertilise these species with standard formulas in limestone soils.
The Hydrophobic Soil Problem — And the Two-Part Fix
Water Corporation’s own guidance is explicit: Perth’s sandy soils are commonly water repellent. The symptom is visible — water pools on the surface around a plant rather than soaking in. If you press your finger into dry Perth sand and the surface repels rather than absorbs moisture, you have a hydrophobic soil problem.
The fix has two components and both are needed.
Component 1 — Bentonite Clay
Bentonite clay is a natural swelling clay that dramatically improves the water and nutrient holding capacity of sandy soil. Water Corporation recommends incorporating bentonite clay into the top 30cm of soil before planting — and this is specifically cited as appropriate for native plant establishment on Perth’s sandy verges and gardens.
For a new tree planting hole in Bassendean sand:
Dig your hole to approximately twice the width and 1.5 times the depth of the root ball
Mix bentonite clay granules into the excavated soil at the rate recommended on the product packaging — typically around 1-2kg per planting hole
Do not pre-soak the granules before mixing into dry soil — add directly to the excavated sand and mix thoroughly through the top 30cm
Backfill around the root ball with the clay-amended mix
Component 2 — Soil Wetting Agent
A soil wetting agent breaks the water-repellent barrier in hydrophobic sand, allowing water to penetrate deeply to the root zone rather than beading on the surface. Water Corporation specifically recommends applying a quality soil wetting agent during native plant establishment to increase soil wettability.
Application:
Apply a quality wetting agent to the planting area before and immediately after planting
Always water the wetting agent in until it foams — this is the confirmation it has activated and is working
Reapply at the start of winter and in early summer as recommended by the manufacturer — Water Corporation’s guidance specifically cites these as the optimal reapplication times for Perth conditions
Choose products displaying the Waterwise and Smart Approved WaterMark symbols
The Planting Process — Step by Step
Step 1 — Timing
Plant in late autumn or early winter — May through July in Perth. Winter rainfall does the establishment watering for you. A tree planted in June and watered in by natural rainfall through July and August has a root system developing in cool conditions before it faces its first Perth summer. Never plant in summer. A newly planted tree in 40-degree Perth heat with a root ball sitting in hydrophobic sand is almost certainly dead before Christmas.
Step 2 — Prepare the hole
Dig approximately twice the width of the root ball and 1.5 times its depth. In Bassendean sand this takes minutes — use a spade or post-hole digger. In limestone soils you may need a mattock or crowbar for compacted areas.
Step 3 — Amend the soil
Mix bentonite clay through the excavated soil. Apply wetting agent to the base and sides of the hole. Allow it to begin activating before placing the tree.
Step 4 — Check the root ball
Before planting, inspect the root ball. If roots are circling the container, gently tease them outward. Circling roots left uncorrected will continue circling and eventually girdle the trunk as the tree matures — a slow death that can take years to become visible. If roots are severely pot-bound, score the root ball lightly with a clean knife.
Step 5 — Set the depth
The top of the root ball should sit at or very slightly above the surrounding soil level. Never plant deep — burying the root flare invites fungal disease at the base of the trunk. In Bassendean sand, setting the tree 2-3cm above soil level and mounding gently around it is acceptable — the sand will settle.
Step 6 — Backfill and firm
Backfill with the clay-amended sand mix, firming gently in layers to remove air pockets. Do not compact aggressively — native tree roots need oxygen as well as water.
Step 7 — Build a watering basin
Mound a low ring of soil just outside the drip line of the canopy — this creates a basin that directs water toward the root zone rather than allowing it to run off. In flat Perth gardens this is particularly important.
Step 8 — Water in thoroughly
Water deeply immediately after planting until the soil is saturated to the depth of the root ball. Apply the wetting agent at this stage if not already done, and water until it foams. For a newly planted tree in Perth sand, this first watering is the most important single action you will take.
Step 9 — Mulch
Apply a 5-10cm layer of coarse woody mulch over the planting area, extending to the drip line of the canopy. Keep mulch clear of the trunk by at least 10cm — mulch against the trunk holds moisture and encourages collar rot. Mulch reduces evaporation, moderates soil temperature, suppresses weeds, and gradually improves soil organic matter as it breaks down. Water Corporation specifically recommends coarse mulch of 5-10cm depth for Perth native plantings.
Step 10 — Stake if required
Silver Princess (Eucalyptus caesia) is top-heavy and must be staked for the first two years. Use two stakes placed either side of the root ball, not through it, with a flexible tie that allows some trunk movement — movement is how trees develop trunk strength. Remove stakes after two years maximum. Leaving stakes too long prevents trunk development and can cause damage as the trunk grows into the tie.
The Phosphorus Warning — The Single Most Common Killer of WA Native Trees in Gardens
This is the most important section in this article for anyone planting Banksia, Hakea, or Grevillea.
All members of the Proteaceae family — which includes Banksia, Hakea, Grevillea, and Adenanthos — have evolved on some of the most phosphorus-deficient soils on Earth. To extract the tiny amounts of phosphorus available in native WA soils, these plants developed specialised “proteoid roots” — dense clusters of fine rootlets that are extraordinarily efficient at phosphorus uptake.
When standard fertiliser is applied to these plants, those same efficient roots absorb far more phosphorus than the plant can process. The result is phosphorus toxicity — leaf tip burn, interveinal chlorosis, progressive dieback from oldest leaves inward, and in severe cases complete plant death. Peer-reviewed research published in plant science journals documents this specifically for Banksia grandis and multiple Hakea species.
The Australian Native Plants Society is explicit: standard fertilisers with typical N:P:K ratios are dangerous to phosphorus-sensitive Proteaceae.
The rules for your Treebate tree:
For Banksia and Hakea species — the safest approach is no fertiliser at all. Perth’s sandy soils are exactly what these plants evolved for. They are not struggling in low-nutrient sand — they are thriving in their natural growing medium. Adding fertiliser is not helping them. It is poisoning them.
If you feel you must fertilise — perhaps in the first season while establishment is occurring — use only a certified low-phosphorus native fertiliser. Look for products specifically labelled for Proteaceae or WA native plants. Osmocote Pro Low P and similar certified low-phosphorus formulations are appropriate. Standard Osmocote, Dynamic Lifter, blood and bone, and general purpose fertilisers are not appropriate for Banksia or Hakea.
Never apply standard fertiliser near the root zone of an established Banksia or Hakea, even as a lawn fertiliser. The root system extends well beyond the visible canopy and will take up what is available.
For Eucalyptus species — Silver Princess, Coral Gum, Tuart, Jarrah — standard low-phosphorus native fertilisers are acceptable in small quantities during establishment. These species are not Proteaceae and do not share the same phosphorus sensitivity, though they do not require heavy fertilising in Perth’s conditions.
Watering Through Establishment — The First Two Summers Are Critical
A WA native tree established in its first winter and cared for through its first summer will generally require minimal supplemental watering from its second year onward. The establishment period is everything.
First winter (planting season): Allow natural rainfall to do the work. Supplement only during dry spells of more than two weeks. Water deeply and infrequently — one deep watering is more effective than daily surface watering. Deep watering encourages roots to follow moisture downward, building the deep root system that makes the tree drought resistant.
First summer: This is the critical period. A newly planted tree has not yet developed the deep root system to access subsoil moisture. Water deeply once or twice per week depending on temperature. During heatwaves above 38 degrees, water on the day before and the day after the heatwave — not during it. Afternoon watering during extreme heat causes rapid evaporation and can stress plants further.
Second winter onward: Most established WA native trees in Perth require no supplemental watering beyond their second winter. This is the point where your planting investment pays off — a tree that looks after itself through Perth summers without irrigation.
Signs of underwatering: Leaf curl and droop during the day that does not recover overnight. Brown leaf tips progressing inward. Premature leaf drop.
Signs of overwatering: Yellowing leaves across the whole canopy. Root rot (particularly for Banksia in poorly drained soil). Fungal issues at the base of the trunk.
The Tree Recovery Program Connection
If you are planting as part of a PSHB tree replacement under the WA Tree Recovery Program, your eligible claim covers more than just the tree.
Under the Tree Recovery Program, a single transaction covering the replacement tree plus establishment items — soil, soil improver, mulch, and wetting agents — can all be claimed up to the $150 cap, provided they are purchased together in a single transaction.
This means the bentonite clay, the wetting agent, and the mulch described in this guide are potentially claimable costs for residents with a valid DPIRD Tree ID from an authorised PSHB tree removal.
Standard Treebate covers the tree purchase only. The Tree Recovery Program covers the full establishment basket. If you have a DPIRD Tree ID, make sure you purchase your tree and establishment items together in a single transaction and keep the itemised tax invoice.
For the full breakdown of both programs and how to determine which applies to you, read our WA Tree Recovery Program vs Treebate guide.
Quick Reference — Planting Checklist
Run through this before you dig the hole.
Timing
☐ Planting in late autumn or winter (May–July) — not summer
Soil preparation
☐ Bentonite clay mixed through excavated soil to 30cm depth
☐ Soil wetting agent applied to hole and watered in until foaming
☐ Hole dug to twice the width and 1.5 times the depth of root ball
Planting
☐ Root ball checked — circling roots teased outward
☐ Tree set at correct depth — root flare at or slightly above soil level
☐ Backfilled and firmed in layers
Post-planting
☐ Watering basin formed just outside drip line
☐ Deep watered immediately after planting
☐ 5-10cm coarse mulch applied — clear of trunk by 10cm
☐ Stakes installed if required (Silver Princess — mandatory)
Fertiliser
☐ No standard fertiliser applied — especially for Banksia, Hakea, Grevillea
☐ If fertilising — certified low-phosphorus native formula only
First summer
☐ Deep watering schedule established — once or twice per week during heatwaves
☐ Wetting agent reapplied at start of summer as directed
The Bottom Line
Perth’s sandy soil is not the enemy of native trees — it is their natural habitat. The problem is not the soil itself. It is the hydrophobic surface layer that forms when that soil dries out, preventing water from reaching the root zone of a newly planted tree before it has developed the deep roots to access subsoil moisture.
Fix the hydrophobic layer at planting time with bentonite clay and a soil wetting agent. Mulch to lock moisture in. Water deeply through the first summer. Never apply standard fertiliser to Banksia or Hakea. Stake Silver Princess for two years.
Do those five things and your Treebate tree will be establishing roots through its first winter and feeding itself through its second summer — long before the government rebate has been spent.
Use our Tree Selection Tool to confirm your chosen species is PSHB-verified for your suburb before purchasing.
Soil preparation guidance sourced from Water Corporation WA Waterwise Garden guides, Water Corporation Verge Designs page, and Water Corporation Sandy Soil Improvement guidance. Phosphorus toxicity information sourced from the Australian Native Plants Society (ANPSA), peer-reviewed research published in plant science journals, and published WA horticultural guidance. Swan Coastal Plain soil classifications sourced from published WA soil surveys. Treebate program rules verified against DWER FAQ (18 September 2025) and ServiceWA Treebate page (12 March 2026). WA Tree Recovery Program information verified against DWER Tree Recovery program documentation (updated 30 March 2026). treebate.com.au is an independent guide and is not affiliated with DWER or the WA Government. Final rebate approval rests solely with DWER and ServiceWA.