Case Studies

Moisture-saving weed control for native planting at scale

by Brad Stuart | Oct 20, 2025

Swapping coir for Terra Lana’s all-wool DagMat delivered better coverage, moisture retention and stability, greening a major gateway at scale.

With around 200,000 native plants, the Piarere roundabout is more than an intersection; it’s a new landscape that softens infrastructure and signals arrival between Waikato and the Bay of Plenty.

Civil contractors Evergreen Landcare handled the full planting and chose Terra Lana’s DagMat, an all-wool, 100% biodegradable weedmatting for weed suppression, ground stabilisation and moisture retention. It replaced the usual coir/coconut matting and, according to Evergreen’s General Manager Bryce Alsemgeest, delivered a noticeably tighter bond that keeps soil covered, stabilises the ground and reduces maintenance.

‘This project shows how thoughtful product selection, sustainable practices and good collaboration can deliver outstanding results,’ says Bryce. ‘DagMat was new to us, but it out-performed coir, with better coverage, better stability, less hassle.’

Easy install, excellent coverage

Across 35 native species – from low shrubs to maturing trees – Evergreen introduced a few smart tweaks: worm castings instead of standard compost, and a blanket of DagMat over treated soils before any planting began. One-litre plants were the default, with larger specimens in key locations. The final step was simple: plant straight through the DagMat, which meant no extra bark layer was needed.

On site, the crew found DagMat faster to lay and more secure on slopes than other materials. A 150mm overlap with pegs at roughly 1m centres gave consistent, tidy coverage, which was especially valuable on steeper batters and around tight curves.

Natural, local and genuinely sustainable

Choosing DagMat was both practical and principled. Made in New Zealand from local wool, it tackles the often-overlooked category of weed matting, which has historically been imported. ‘By using Terra Lana’s all-wool product, we reduced transport emissions and supported a more circular, low-carbon approach,’ says Bryce. ‘It suppresses weeds, retains moisture to help establishment, and then breaks down naturally over time.’