NZLA Blockade – Herbicide (Barricade Herbicide)
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NZLA Blockade – Long-Lasting Pre-Emergent Weed Control for Lawns and Garden Beds
NZLA Blockade is a professional-grade pre-emergent herbicide containing 480 g/L Prodiamine (suspension concentrate). It prevents new weeds from sprouting by creating a protective barrier in the soil—stopping weed seeds from germinating before they ever become a problem.
Known globally as Barricade, NZLA Blockade delivers up to six months of residual weed control in lawns and garden beds. It’s trusted by lawn professionals and now available in smaller 250 mL and 500 mL packs, making premium lawn care easy and affordable for New Zealand homeowners.
Why choose NZLA Blockade?
- Prevents weeds before they appear – ideal for lawns and garden beds
- Up to six months of protection from a single application
- Professional-grade Prodiamine, available in homeowner-friendly pack sizes
- Safe on established warm-season lawns when used correctly
- Reduces time spent hand-weeding and improves lawn appearance year-round
- Can be used under mulch or on garden beds for long-term weed prevention
How NZLA Blockade works
Blockade forms a thin protective layer in the top few centimetres of soil. When weed seeds begin to germinate, their young roots contact the treated zone and stop developing. The result is simple: no germination, no weeds.
Established lawn grass and ornamentals are safe because their roots sit deeper than the treated layer. To activate Blockade, it must be watered in with at least 6 mm of irrigation or rainfall within seven days of application.
Where you can use it
Blockade can be used on most established warm-season lawns in New Zealand, including:
- Buffalo
- Couch (common and hybrid)
- Kikuyu
- Zoysia
- Queensland Blue Couch
- Seashore Paspalum
- It’s also suitable for garden beds and landscaped areas (under mulch or around established shrubs) to keep them weed-free for months.
Weeds controlled by NZLA Blockade
Blockade prevents the germination of many of New Zealand’s most persistent grassy weeds, including:
- Summer Grass / Crab Grass
- Barnyard Grass
- Crowsfoot Grass
- Rat’s Tail Fescue
- African Lovegrass
- Winter Grass (Poa annua)
- Paspalum species
- Bahia Grass
Because Blockade is a pre-emergent, it won’t kill weeds that are already established—so it’s best used as a preventive measure.
How to apply
- When to apply: Before weeds germinate. For summer weeds, apply in late winter or early spring. For winter weeds (like Poa annua), apply in late summer or early autumn.
- Rate: Use between 30–80 mL per 100 m², depending on weed pressure, soil type and application type. Turf 10- 30ml per 100m² with garden beds, potted plants and gardens 40-80ml per 100m².
- Activation: Apply light irrigation or rainfall (6 mm+) within seven days to bind the herbicide into the topsoil.
- Coverage: Spray evenly across the area to form a consistent, uniform barrier.
For non-lawn areas such as driveways, paths, or fence lines, Blockade can be tank-mixed with glyphosate for instant weed knockdown and extended residual control. (Avoid applying such mixtures over desirable plants.)
Tips for best results
- Apply to healthy, established lawns with no bare soil patches.
- Mow and remove clippings before application so the product reaches the soil surface.
- Avoid disturbing the soil after application—this breaks the herbicide barrier.
- Don’t overseed or lay new lawn seed for at least six months after treatment.
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Log InFAQs
Blockade is a pre-emergent herbicide that stops weed seeds from germinating in your lawn or garden. It’s applied before weeds appear and provides up to six months of control.
When applied correctly and watered in, it provides residual weed prevention for up to six months.
Apply before weeds start to appear. For summer weeds, apply in late winter or early spring. For winter weeds (like Poa annua), apply in late summer or early autumn.
Yes. Blockade needs at least 6 mm of rainfall or irrigation within seven days to activate. Without water, it will sit on the surface and won’t form the barrier needed to stop weed germination.
Yes. It’s safe for established plants and can be applied under mulch or around shrubs to stop weeds emerging through soil gaps.
No, it’s safe on established warm-season lawns like couch, kikuyu, buffalo, and zoysia when used as directed. Avoid use on newly seeded or recently laid lawns.
No. Blockade prevents new weeds from growing but won’t kill ones already up. For existing weeds, use a knockdown herbicide like glyphosate first, then apply Blockade to keep new weeds from coming back.
Yes. For non-lawn areas like driveways or fence lines, you can mix it with glyphosate for both immediate and long-term weed control. Always read label directions and test compatibility first.
Typically once or twice a year is enough. Apply again after about six months or when you notice new weeds emerging.
Wait at least six months before sowing new lawn seed or laying new grass, as the barrier will also prevent new lawn seed from germinating.
