Early Spring Iris Borer Control

Hi it's me again, back with my boring borer questions. I had planned to sprinkle merit grub control granules around the irises after spring cleanup, but this weather is so crazy this year that I haven't even begun spring cleanup. But we did have 2 or so really warm days - 70 - 80 degrees. Could the borers hatch in one warm day like that? If so, would the freezing temps we have just had kill them? (hope, hope, hope...) Any advice? Should I just cleanup around the irises asap and then sprinkle the merit?
Sharon

Supposedly, borers start hatching after the first two consecutive 70 degree (or warmer) days. I don't know how true that is, but it's what I've read a number of times. I have no idea whether subsequent freezing weather would kill them.

I'd go ahead and finish your cleanup and apply Merit as quickly as possible. Make sure you water it in thoroughly after application.

Laurie