What is the green spray they are spraying against the clay embankments next to the roads in New Zealand?

Question

When I drive to work, I now notice some green spray clinging to the naked clay walls next to the road where construction has been going on, along Portobello Road in Dunedin.

What is that stuff?

Is it grass seed of some type?

Answer 1

yep you are right. it is grass seed mixed with a bedding agent (old newspaper i think) to help it stay in place and stop the birds eating it.

they used the same stuff outside mitre10. it has green food grade colouring in it so they can see where they have sprayed it.

Answer 2

Yep, Mclarenman is quite right.

It's a papier mache brew that quickly hardens and holds loose soil in place while the seed within it germinates and takes over.

It's called Hydraseeding, and is used extensively on the Central Volcanic Plateau whenever the roadside bank has been disturbed. Without it, the pumice would blow away in the sunny weather, or wash away in the rain.

The main seed within the brew used for pumice land is a legume called Lotus major. It has strong deep roots that hold the bank firmly once it's established. And in that brew, it establishes very quickly.

I'm not sure what the seed sprayed in Dunedin will be, I don't think Lotus grows in coastal Otago.