Posted: 20/12/2015 at 14:35
Chris, I use nematodes in autumn for leatherjackets and that is sufficient for me.
if you think your infestation warrants it you can apply in spring but there is nothing else you can do except the traditional (organic) way of damping the area and covering overnight with black plastic. you can then brush off the leatherjackets.
however, the organic way, over seeding in spring and nematodes in autumn...August/September .....is the way to go Chris
leatherjackets wont "spread" to your neighbour's lawn or do damage from spring to late summer