How to Oversow Your Lawn for Winter — Keep It Green All Year

Why Does My Lawn Go Brown in Winter?

Warm-season grasses like Kikuyu, Couch and Buffalo go dormant when soil temperatures drop below 15°C — turning brown or straw-coloured through the cooler months. This is completely normal, but if you want a green lawn year-round, oversowing with a cool-season ryegrass is the answer.

What is Oversowing?

Oversowing means sowing cool-season grass seed directly into your existing lawn. The ryegrass germinates quickly, provides lush green coverage through winter, and then naturally recedes as your warm-season grass wakes up in spring.

Which Seed Should You Use?

Turf Type Annual Ryegrass — fastest germination (5–7 days), fine texture, ideal for a single winter season. Naturally dies off in spring. Best value for oversowing. Covers 250m² per 5kg.
Turf Type Perennial Ryegrass — finer texture, deeper green, more wear tolerant. Persists longer into spring. Covers 300m² per 5kg oversowing.

When to Oversow

Sow in autumn (March–May) as temperatures begin to cool and your warm-season lawn starts to slow down. Aim for soil temperatures between 10–20°C for best germination. Don’t wait too long — seed sown in June or July will struggle in cold soils.

Step-by-Step Oversowing Guide

Mow short — cut your existing lawn as low as possible (below 20mm) to reduce competition and allow seed to reach the soil
Scarify — rake or scarify the surface to expose bare soil between existing grass plants
Apply seed evenly — use a spreader or broadcast by hand at the recommended rate
Drag or rake lightly — work seed into the surface for good soil contact
Water gently twice daily — keep the surface moist until germination (5–10 days)
Mow regularly through winter — keep ryegrass at 30–40mm for best appearance

Spring Transition

As temperatures warm in September–October, your warm-season grass will begin to grow again and naturally outcompete the ryegrass. You can help the transition by gradually raising your mowing height and reducing watering frequency.