Grass Grub Damage: Restore Your Pastures and Protect Future Growth
Grass Grubs Are Hitting Your Pastures — But You Can Fight Back
Grass grub (Costelytra zealandica) larvae are one of New Zealand’s most destructive pasture pests. They feed on roots, weaken clover and grass, and leave bare patches that reduce pasture growth and feed availability.
Signs of grass grub damage:
Patchy or bare pasture areas
Reduced clover establishment and vigour
Slow recovery after grazing
Poor nutrient uptake despite fertiliser applications
Left unmanaged, infestations can cost $200–$500+ per hectare in lost pasture productivity, poor regrowth, and regrassing costs.
Why Traditional Solutions Aren’t Enough
Chemical insecticides like chlorpyrifos are now restricted, and re-sowing or over-fertilising only addresses the symptoms, not the root cause. Pasture recovery depends on soil health and biology, which is often compromised in heavily grazed or compacted soils.
Farmers need a solution that works with the soil ecosystem — supporting natural pest suppression and helping pastures bounce back stronger.
How DCT Supports Pasture Recovery and Natural Grub Control
DCT’s soil recovery solution doesn’t kill grass grubs directly. Instead, it strengthens your pasture and soil to reduce grub impact naturally:
Boosts soil biology:
Healthy, biologically active soils support natural predators and microbes that compete with or suppress grass grub larvae.Improves root growth and pasture vigour:
Stronger roots make plants more resilient to feeding damage, allowing pastures to recover faster.Enhances nutrient uptake:
Improved nutrient availability helps pastures outgrow the damage, filling bare patches and restoring feed value.Supports long-term soil health:
Over time, biologically active soils become less hospitable for grub larvae, reducing pressure in future seasons.
When and How to Use DCT for Best Results
Timing: The most effective time to support soil-based grass grub control is late summer to early autumn, when larvae are small and soil biology is most active. Applications at this time help reduce pasture damage and improve recovery before winter.”
Soil conditions: Works best in soils with adequate moisture to support microbial activity.
Expected outcomes: Improved root development, faster regrowth, and healthier, more resilient pastures.
Best Timing for Grass Grub Management (NZ)
Primary Window: Late Summer → Early Autumn
(February – April)
This is the most effective and commercially relevant timing.
Why this window works best:
Grass grub eggs have hatched
Larvae are small, actively feeding, and near the surface
Soil temperatures are still warm → biology is active
Pastures can still respond and recover before winter
What this achieves:
Reduces the impact of larvae while they’re most vulnerable
Strengthens root systems before winter stress
Improves pasture recovery and limits patch expansion
Spring (September – October)
Spring applications are about recovery, not prevention.
Larvae are larger and feeding deeper
Damage may already be severe
Soil biology is only just waking up
Why You Can’t Wait
Every season left with grub-damaged pasture costs you feed, growth, and profit. Acting now supports natural pest suppression, restores pasture vigour, and reduces long-term grub pressure.
See How DCT Can Help Your Pastures Recover
Restore pasture health, improve soil function, and reduce the impact of grass grubs naturally. Take action today and give your pastures the best chance to bounce back stronger.
Restore Pastures After Grass Grub Damage
Grass grub larvae feeding on roots can leave paddocks patchy and underperforming. DCT’s soil recovery solution strengthens soil biology, boosts root growth, and supports natural grub suppression — helping pastures recover faster and stronger.
Faster pasture recovery after grub damage
Stronger roots and more uniform growth
Improved nutrient uptake and long-term soil health
Biological Suppression of Pests
Our product promotes the growth of beneficial microbes, fungi, and bacteria that:
Outcompete harmful pest larvae
Disrupt grub and porina lifecycles
Create a dynamic, oxygen-rich soil environment that pests don’t like
Healthy soil biology adds natural pest pressure — and that means fewer grubs without chemicals.
Proven in the Field. Backed by Science.
Easy to Use. Easy to Fit In.
Can be applied on its own or alongside fertiliser (e.g. urea)
Compatible with biological, regenerative, or organic systems
No re-entry intervals. No withholding periods. No soil residue concerns.
Ready to Shift the Balance in Your Favour?
If you're tired of chasing pest damage with short-term fixes, it's time to take a smarter, soil-first approach.
DCT helps you build soil that works for you, not for the pests.
Contact us today to learn more
Serving farmers and growers across New Zealand
Act now — every day your paddocks remain grub-damaged reduces feed and growth for your farm.