Termites in My Garden: Is My House at Risk? Perth

What it means when you find termites in your garden

Subterranean termites live underground and tunnel through soil in search of wood and moisture. If you find them in a tree stump or fence post, a feeding population is present in your soil. See what termites actually look like to confirm the ID.

Termite workers on timber showing pale coloration and characteristic body structure — Termite workers foraging on timber.

Termites need food (wood) and water to stay alive. Your garden often provides both. Tree stumps and fence posts are prime harbouring spots. The question is not whether they're there, but whether the colony is close enough to also access your house.

How close is the colony to your house

Subterranean termites travel at least 50 metres from the colony via underground tunnels to find food. You cannot tell by sight alone. Finding activity in the garden means there is an active colony somewhere nearby in the soil.

Termites in tree stumps and garden timber

If you find them in a tree stump or fence post, the timber is already hosting a feeding population. Tree stumps, fence posts and other garden timber are where colonies nest and feed. Subterranean termites need contact with soil and moisture to survive, and garden timber against the soil provides both.

They also hold moisture and create soil contact with your walls. This gives termites a direct route to the slab edge and entry points into weep holes or window frames.

From there, they can tunnel underground and reach timber framing in the house if a continuous pathway exists. The key risk factor is anything that bridges the gap between garden soil and your building.

Will termites spread from garden to house

Termites will spread to your house if a tunnel route exists and the house offers moisture and entry points. Perth's brick-and-tile homes from the 1970s and 1980s have garden beds built up against the walls over decades.

Newer estates in Alkimos, Butler and Clarkson often have a physical barrier or chemical system installed at construction, but these only work if they are not bridged by a new deck, a raised garden bed, or paving poured over the treated zone.

Termites swarm from November to April. Finding activity in the garden during this window is a signal to act.

What you can do yourself (non-chemical)

Start with harbourage removal. Pull garden beds back from the brick face. Remove dead wood, mulch piled against walls, and tree stumps. The goal is to create a clear sight line between soil and wall, so termites have no hidden pathway to the house.

Fix moisture. Leaking air-conditioner drains, irrigation lines that spray the wall, and poor surface drainage all make soil moist. Termites need moisture to survive. Redirect water away from the foundation. If your sub-floor is damp and your home has a raised timber floor, improve ventilation.

Monitor the garden timber you keep. If you have a tree stump, inspect it every few months. Tap it with a screwdriver or hammer. If it sounds hollow, the timber is compromised and a professional inspection of the house may be needed to confirm whether the colony has also accessed the building.

Do not apply pesticides to soil or timber yourself without checking the label. It is illegal to apply pesticides in a manner that is not indicated on the label. If you want to treat a stump or fence post, check APVMA PubCRIS (the public chemical registration database) for registered termite products and read the label in full before use.

What not to do

Do not spray termites yourself. Your best outcome from a DIY attempt is to have solved nothing. Your worst outcome is to have made treatment harder later.

Do not assume that because termites are in the garden, your house is already infested. An inspection will tell you whether they have accessed the building.

Do not wait indefinitely. If you have confirmed termites in the garden (by seeing them), book an inspection within a few weeks. The sooner you know where the colony is, the sooner you can decide on a management plan.

When to call a professional

Call as soon as you confirm termites in the garden. This is the first step of any management plan. See termite inspection to AS 4349.3.

We inspect the roof void, sub-floor, interior, exterior and grounds, take moisture readings, photograph evidence, and give you a written report with recommendations.

Treatment of garden termites depends on what's infested. A tree stump or fence post can be removed or treated. A termite colony under the soil may require a perimeter barrier or baiting system to prevent entry to the house. Work is carried out by, or under the direct supervision of, a technician holding a WA pest management technician's licence under the Health (Pesticides) Regulations 2011.

What it costs

You receive a full AS 4349.3 report, photos, moisture readings and recommendations.

If a management system is needed, the cost depends on the perimeter length and how much is paved. A chemical barrier installed to AS 3660.2 typically ranges from $2,500 to $5,500. A baiting system is $1,500 to $3,000 plus an ongoing monitoring program. Garden timber treatment varies based on what's affected. See the full investment guide for more detail on what moves the cost.

There is no call-out fee.

Frequently asked

Are termites in my garden a sign they are already in my house?

Not always. Termites forage widely from their nest. Finding them in the garden means the colony is close, but the house may not yet be breached. An inspection will show whether they have accessed timber framing, skirting boards or other structural wood inside. Learn more about termite damage and what it means.

What should I do with a tree stump if it has termites in it?

Removal is often the simplest option. If you keep it, inspect it every few months for signs of termite activity. Monitor the soil around it and treat the colony underground if it poses a risk to the house.

Can I treat termites in my fence myself?

Check APVMA PubCRIS for registered termite products and read the label in full. However, if the fence is close to the house, professional treatment of the surrounding soil and entry points is more effective than fence-only work.

How often should I inspect my garden for termites in Perth?

If you have a history of termites in the area or garden timber, check regularly. A professional termite inspection every 12 months is a sensible default for Perth's northern suburbs, especially in older suburbs where multiple properties may be at risk.

Will a professional treatment of the garden stop termites spreading to my house?

This is installed by trenching in garden beds and drilling and injecting through paving and concrete. The system is checked annually by inspection to ensure it remains intact. Pests can re-enter from next door, so the management system is part of ongoing management, not a one-time fix.

What if termites are in my mulch or garden beds?

Pull the mulch and garden beds away from the house. Replace it with gravel or coarse sand if you want ground cover, but keep it clear of the brick face and slab edge.

Is there a specific season when garden termites are most active in Perth?

Yes. Termites swarm from November to April.

What is the difference between termites in the garden and a termite infestation in my house?

Garden termites are foragers, eating wood outside. A house infestation means they have entered the building and are feeding on structural timber, skirting boards or framing. Finding one doesn't mean the other, but presence in the garden increases the risk. Only an inspection can tell you whether the house is breached.

Sources

Text your suburb and what you're seeing to 0468 170 107 for a written price.

Termite Inspection Perth, the full service and the investment
Pest management investment ranges in Perth, every service with a typical range
What's my pest?, pick what you saw
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