I'm with the layer of grit method along with sticky traps to get those that are flying.
I had a really bad infestation one year and I believe the grit made a huge difference - advised by Mcdood when I was trying to take dahlia cuttings - still trying by the way ;(
I had a really bad infestation one year and I believe the grit made a huge difference - advised by Mcdood when I was trying to take dahlia cuttings - still trying by the way ;(