Will a Weed Burner Kill Paspalum? Suppression Only

Paspalum — dallis grass, sticky heads, water grass — is the one people ask about when they're sick of those tall seed stalks reappearing four days after mowing.

The answer: a weed burner suppresses paspalum. It doesn't kill established plants. Same story as most perennial grasses, and it's worth knowing why before you buy anything.

Why grasses are hard for flame

There's a general rule with thermal weeding: it works better on broadleaf weeds than on grasses. Broadleaf plants tend to carry their growing points up where you can reach them. Grasses evolved alongside grazing animals and fire, and they keep their growing points down at or just below ground level, protected by leaf sheaths and soil.

Paspalum takes that further. It's a tufted perennial that grows from a central crown packed with short creeping rhizomes, sitting right at ground level, over a deep fibrous root system. It's summer-active and goes dormant through winter, then resprouts from that rootstock the moment conditions suit.

So a flame pass burns the leaf off. The crown, the rhizomes crowded around it and the root system are all still there, fully loaded. Give it a week of warm weather and a bit of moisture and it's back.

This isn't a flame-specific failure, and it's worth saying because people assume mowing is different: mowing and slashing don't control established paspalum either. They take the seed heads off, which is worth something, but they don't touch the plant.

Where suppression is still genuinely useful

"Doesn't kill it" is not the same as "pointless". There are real jobs here:

• Edges and hard surfaces. Paspalum creeping into a gravel driveway, a path edge, along a fenceline or around a tank stand. You're not eradicating it, you're keeping the line clean, and a burner does that fast without spraying near the vegie patch or the dog.
• Stopping seed. A mature paspalum plant can throw more than 250,000 seeds. Knocking the flower stalks down before they mature stops that year's contribution to the seed bank, which matters more than it sounds.
• Seedlings. Young paspalum that hasn't built a crown yet is much easier to kill outright. If you've cleared ground, staying on top of the new ones is realistic.

What it won't do is clear paspalum out of a paddock or a lawn.

What actually kills an established plant

For individual plants, physical removal works — but you have to get the whole crown out, which usually means a mattock rather than a hand fork. Leave part of the crown behind and it regrows from it. That's slow, but for a scattered handful of plants in a lawn it's completely doable and permanent.

Beyond that, it's competition and management: paspalum takes hold in thin, damp, compacted ground, so improving drainage and thickening the sward is the real long-term lever. In turf there are pre-emergent products aimed at it, which is a different conversation.

Same goes for couch and kikuyu

If you've got runner grasses coming into places you don't want them — couch, kikuyu, buffalo escaping a lawn edge — the answer is the same. Flame knocks the top off and the runners survive. Useful for holding an edge, useless for eradication.

Short version

Suppression only. Paspalum regrows from a crown full of short rhizomes that surface heat can't reach, and mowing doesn't beat it either. A burner is genuinely handy for keeping it out of gravel, paths and fencelines and for stopping seed heads maturing — but if you want an established plant gone, dig the whole crown out with a mattock.

Want the straight verdict on your weed? See the weed-by-weed guide, or ring us on +61 449 268 131 and just describe it. If it's the wrong tool we'll tell you.