Bird repellent grass seed in NZ: is it worth the money?

I thought I’d share my view on bird repellent coated grass seed. Coated grass seed gets sold on the promise birds won’t touch it. The seed is coated with a repellent (methyl anthranilate or anthraquinone) that’s meant to stop birds like sparrows, starlings, blackbirds and thrushes from pecking through your new lawn.

Most people don’t realise that it only actually works on some birds. Research on both actives shows they reduce bird damage, but the effect varies by species, and both chemicals wash off under rain and UV.

I’m not aware of anyone in the professional turf industry using coated seed. Greenkeepers and sportsfield managers all buy uncoated. If coated seed actually stopped the birds, the pros would have been onto it. They’re not.

You’re also paying for coating, not seed. Approximately 50% of the weight in a coated bag is coating material. A 1kg bag of coated ryegrass works out to 500 grams of actual seed. An uncoated kilogram of perennial ryegrass is about 500,000 seeds. To get the same ground cover from coated seed, you’ll need to sow at close to twice the rate, and you’re paying a premium per kilogram on top because of the coating.

The better answer is sowing technique. Rake or drag the seed into the soil surface, top with a very thin layer of top-dressing mix and keep it moist. Seed covered by even a few millimetres of soil is out of reach of most lawn-feeding birds, and it germinates faster because it’s in contact with damp soil. Frost cloth is another solid option, especially if you’re sowing fescues as the result tends to be a better strike anyway and the seed is normally sitting on the profile longer before germination.

The other option is to just sow at the top of the recommended rate and accept you’ll lose a small percentage to birds. With enough seed on the ground you’ll still end up with the coverage you want. Every time I sow, I sit on my sofa watching the birds eating my lawn seed, but not once has it affected the end result.

Hopefully that clears up the bird question! I’ll add this to the bird category.