Toad Rush (Juncus bufonius)
Toad rush is a small, tufted, grass-like annual weed that thrives in wet, compacted, or poorly drained soils. It’s a common problem in bowling greens, golf courses, and damp home lawns throughout New Zealand.
Germinating mainly in autumn, it forms fine, wiry tufts that are bright green in winter before turning brown or reddish as the weather warms. In turf, its uneven texture disrupts ball roll and surface smoothness, and its clumpy habit spoils the overall appearance of fine turf areas.
Toad rush is most often introduced through contaminated topdressing soil, and once established, it produces large numbers of tiny seeds that can survive in the soil for years — making it a persistent problem on poorly drained turf surfaces.
Identification
In its early stages, toad rush can be mistaken for grass due to its fine, glossy green leaves. However, there’s one key difference: toad rush leaves have no veins, whereas true grasses have a central vein running down the blade.
Plants grow as tight tufts with few leaves, mostly at the base, and a fibrous root system. In late spring, the foliage takes on a khaki or red tone as the plant dies back under summer heat. Mature plants produce tiny brown seeds that are easily spread by wind, water, or topdressing materials.
Why It’s a Problem
Toad rush competes with desirable turf species and can dominate wet, compacted, or newly renovated areas where turf cover is thin. It grows faster than most fine turf species in cool, damp conditions, creating uneven playing surfaces and poor ball movement on greens.
Because it germinates quickly and repeatedly, even well-managed surfaces can become infested if topsoil or drainage issues aren’t addressed.
Management and Prevention
The best control of toad rush comes from proactive turf management rather than relying solely on herbicides.
Cultural control methods:
- Improve drainage: Toad rush thrives in saturated soil. Core aeration, sand topdressing, or surface contouring to remove puddles will reduce conditions that favour it.
- Avoid contaminated soil: Test topdressing soil before use. A simple germination test in a seed tray can help identify toad rush seed contamination.
- Maintain dense turf cover: Keep lawns or greens actively growing so light can’t reach the soil surface where weed seeds germinate.
- Regular mowing: Frequent mowing prevents the weed from producing seed heads and helps maintain smoother playing conditions. Keep mower blades sharp and properly adjusted.
- Fertilise during establishment: Adequate nitrogen and phosphorus help the desired turf recover faster after renovation, limiting weed invasion.
Manual control:
On new bowling greens or lawns, hand-weeding can be surprisingly effective — particularly before the plants seed. Removing small patches regularly prevents large infestations.
Chemical Control
Herbicide options for toad rush are limited and should only be used as part of an integrated management plan.
Options include:
- Dalapon: Effective in warmer temperatures but should not be applied early in the season. It’s used mainly in fine turf or bowling greens once summer growth begins.
- Glyphosate (spot-spray): Can be used for isolated patches on domestic lawns, though it will also kill surrounding grass.
- Pre-emergent oxadiazon (Foresite, Oracle): Useful in bowling greens or cotula surfaces after renovation to prevent seed germination, especially where soil contamination is suspected.
- Always follow product label directions and avoid herbicide use on newly sown or delicate turf species such as cotula until fully established.