Buddleia davidii

Buddleia davidii or Butterfly Bush has been planted in many garden, sort of as a first, shelter plant. Indeed at the nursery we propagated it from cuttings as a low shelter plant for farms.

However, the species has escaped and is becoming a problem.

The Waianakarua River has been invaded by the species and it competes with, even beating, gorse!

I see it on the roadsides now and it springs up in my garden and on my drive. Quite quickly too. Daily I walk down my drive and there is always a 100mm plant there to pull out, that wasn't there the day before!

The foliage is grey/green and I note that the roadside spraying contractor does not have much success in controlling the plant. I have no idea what chemical he uses, but that chemical is powerful enough to kill Silver Birch, Broom, Dock and Nodding Thistle. But the Buddleia will die off and regrow.

I use Glyphosate at high rates and add Pulse or dishwashing liquid (who said that? But it is just as good) and I can kill 2m plants.

I am not sure how the seed spreads, it does not seem to fly (in the wind) and I would have expected the seed to be digested in the gut of birds, but obviously not as I suspect they are indeed the carrier.

And the species is being transported around the district in gravel that is quarried on the river bed.

The problem will grow.