How to combat penny wort infestation in Buffalo lawn?

[harryp1]

Just moved into new house with massive penny wort infestation in buffalo lawn Asked at every garden centre and they just shake their head. Any ideas to reduce or preferably eliminate? Previous owner installed agricultural lines to reduce water availability. 

[MitchellMc]

Welcome to the Bunnings Workshop community @harryp1. It's sensational to have you join us, and many thanks for your question about ridding your lawn of pennywort.

There isn't a selective herbicide available that will knock out pennywort (also known as dollarweed) without also damaging your buffalo grass. It's a tricky one because pennywort thrives in damp conditions, and its creeping, spreading habit makes it hard to control once established.

It’s a good sign that the previous owner installed ag lines to help dry the area out, since pennywort loves soggy soil. I'd suggest continuing to improve drainage where possible and reducing watering frequency—Buffalo is fairly drought-tolerant, and drying the soil out is one of the best ways to knock back pennywort over time.

Hand removal can help if you're persistent, especially if you get the roots out as you go. Mulching affected garden areas heavily might also smother it if it's creeping beyond the lawn.

If it's widespread and you're open to a longer-term fix, one option could be to spot-treat with a non-selective herbicide like glyphosate—but only apply it carefully with a small brush or sponge directly to the leaves of the pennywort, taking care not to touch the buffalo. It’s slow going but might be worth a shot for patches that are especially bad.

Please let me know if you have any questions.

Mitchell
 

[harryp1]

Spotting with roundup? Don’t think I have enough life-times to even contemporary that! Thanks for the quick response. H