GIBB-GRO

• Farmers wanting a spring or autumn dry matter boost through the cool-weather feed gap
• Anyone looking to hold pasture growth steady while reducing urea use
• Dairy and drystock farms needing a fast, low-cost response ahead of a feed pinch
• Lifestyle blocks and larger lawns wanting a quick green-up (see our Gibber and lawns article for how this works on turf)
• Anyone already running a knapsack, boom or handgun setup, since Gibb-Gro needs no special application gear

Gibberellic acid (GA3) is a natural plant hormone. Grass and clover already make small amounts of it themselves; Gibb-Gro tops that up so the plant's existing growth process runs faster.

Rather than adding a nutrient, gibberellic acid triggers cell elongation in the plant. Existing leaf cells stretch out, so you see a fast lift in leaf length and dry matter within days, without needing warm soil temperatures the way nitrogen-driven growth does. That's what makes it useful in the cool shoulder seasons when pasture growth naturally stalls.

Because the response comes from the plant's own tissue rather than from added nitrogen, it works alongside your normal fertiliser programme rather than replacing it. Customers commonly use it to smooth out a feed gap while trimming back the urea rate, not as a stand-alone substitute for a full fertility programme.

• Active ingredient: gibberellic acid (GA3), 900g/kg (90% w/w), water-soluble powder
• Application rate: 9g/ha Gibb-Gro + 25ml SprayWetter per 100-200L water
• Water rate: minimum 100-200L water per hectare
• Timing: apply in autumn or spring when soil temperature is 6-13°C; winter application is possible in milder regions but not recommended in Canterbury, Otago, Southland or other high-exposure areas
• Best applied 1-5 days after grazing, once there's adequate green leaf present
• Apply early morning or late afternoon; avoid spraying if rain is expected within 2 hours
• Withholding period: no legal withholding period applies; as good practice we recommend a 1-day withholding period before grazing
• Tank mix: compatible with most herbicides, fungicides, insecticides, fertilisers and adjuvants. As with any new mix, test a small quantity first
• Pack sizes: 500g and 1kg, both resealable foil bags. Need something different? Our sister product Gibber900 (same 900g/kg gibberellic acid) is available in a wider range of pack sizes
• ACVM No. P8012, HSNO Approval Code HSR000747

Is there a withholding period for Gibb-Gro?

There's no legal withholding period, but as good practice we recommend keeping stock off for 1 day after spraying. See our article on withholding periods for gibberellic acid for more detail.

Can I use Gibb-Gro on new pasture?

Gibb-Gro works on established grass and clover leaf, so new pasture needs enough leaf area first before it'll respond well. Our article on using gibberellic acid on new grass covers the timing in more detail.

What's the difference between Gibb-Gro and ProGibb SG?

Both are gibberellic acid, but Gibb-Gro is 900g/kg and ProGibb SG⁽¹⁾ is only 400g/kg. If you're comparing prices, multiply what you're paying for ProGibb SG by 2.25 to get a true active-ingredient comparison against Gibb-Gro.

Will Gibb-Gro let me cut back on urea?

Many of our customers run Gibb-Gro alongside a reduced urea rate and hold their growth. Results depend on your soil and season, so treat it as a way to trim urea use, not replace it outright.

Can I tank mix Gibb-Gro with other products?

Gibb-Gro is generally compatible with other herbicides, fungicides, insecticides, fertilisers and adjuvants. Test a small batch first before mixing a full tank.

What temperature does Gibb-Gro need to work?

Apply when soil temperature is between 6-13°C. It's best suited to spring and autumn; winter application isn't recommended in Canterbury, Otago, Southland or other high-exposure areas.

What pack sizes does Gibb-Gro come in?

Gibb-Gro comes in 500g and 1kg resealable foil bags. If you need a different pack size, our sister product Gibber900 is the same 900g/kg gibberellic acid in a wider range of pack sizes.

Always read and follow label directions before use.

Avoid spray drift onto gardens, vegetables or ornamentals.

Wear appropriate protective equipment when mixing and applying agricultural chemicals.

Got a question about using it? Get in touch - we're happy to help. For full handling information, see the label, product spec and Safety Data Sheet attached to this listing.