Why Your Kikuyu or LM Grass Turns Yellow in Summer (and How to Fix It)

When the summer heat hits, it’s not uncommon for lawns to lose their lush green colour. One of the most frequently asked questions we get is: “Why is my Kikuyu or LM grass turning yellow — and what can I do about it?”

Here’s what’s really going on beneath the surface and how you can bring your lawn back to life.

1. Heat Stress and Watering Issues

In December, high temperatures and strong sun can stress your grass.

• Kikuyu loves the sun but needs consistent deep watering to prevent yellow patches.

• LM Berea, on the other hand, tolerates some heat but may suffer in overly dry or compacted soil.

💧 Solution: Water deeply twice a week, early in the morning (around 5–8 a.m.), rather than light daily watering. This encourages deeper root growth and keeps grass hydrated longer.

2. Nutrient Deficiency

If your grass looks pale or patchy, the soil might be lacking nitrogen or other key nutrients. Yellowing often starts on older leaves and spreads across the lawn if not corrected.

🌿 Solution: Top-dress your lawn with a nutrient-rich compost mix or use a balanced lawn fertiliser. Quick Lawn’s Special Compost Mix releases nutrients slowly, improving soil quality and restoring deep green colour naturally.

3. Lawn Pests or Diseases

Summer also brings pests like lawn caterpillars or fungal infections that can cause yellow or brown spots.

• Kikuyu is hardy but can still be attacked by armyworms.

• LM grass may yellow if moisture lingers too long, encouraging fungus.

🧑‍🌾 Solution: Inspect for pests or fungal patches. If present, treat with a mild lawn-safe insecticide or fungicide. Always follow up with compost or organic top-dressing to strengthen soil recovery.

4. Mowing the Grass Too Short

Scalping your lawn exposes roots to the harsh sun, leading to stress and discolouration.

• Keep Kikuyu around 4–5 cm high.

• Keep LM Berea between 5–6 cm for better heat protection.

✂️ Pro Tip: Never cut more than one-third of the blade length in a single mow.

5. Compacted Soil

If your lawn feels hard underfoot and water runs off instead of soaking in, your soil may be compacted. Roots then struggle to access oxygen and nutrients.

🔧 Solution: Aerate your lawn by poking holes (with a garden fork or aerator) and spreading compost into them. This allows moisture and nutrients to reach the root zone.

✅ The Bottom Line

Yellow grass doesn’t mean your lawn is dying — it’s a sign that it needs better care. With consistent watering, correct mowing height, and regular composting, both Kikuyu and LM grass can bounce back beautifully, even in South Africa’s toughest summer conditions.

Keep your soil nourished and your lawn will stay lush, green, and holiday-ready all season long.