GRUBEX

The temps here have had day time highs of up to 70 degrees. I have begun to put grubex down today. I think this is about right for the timing. Is anyone else using other approaches to stopping borers?

Actually, I would have put Grubex down as soon as the irises broke winter dormancy and began active growth. I never wait until temps reach 70 degrees because I want to make sure the irises have had time to take up the imidacloprid through their root systems BEFORE the borer larvae hatch at 70 degrees. If I were you, I'd get the Grubex down ASAP and water it in thoroughly to get it into the irises as quickly as possible.

Laurie

Hmmm....I've never used this before. Is this the same stuff you might put on your lawn for grubs? How much do you use in flower beds? Here in Iowa, as I imagine in Minnesota, we are still buried under 1-2' of snow. When should I put it down? Thanks a bunch!

For borer control, use some brand of lawn grub control granules that contain the active ingredient imidacloprid (and NO other ingredients besides imidacloprid). I apply it at a rate of 1/2-1 tsp per iris clump, depending on the size of the clump, and water it in well. One application just as irises break dormancy and begin active growth will last all season.

Thanks Laurie. I think I'll try it. Do you only use it on iris clumps or elsewhere in your flower beds as well? Linda

I only use it on the irises for borer control.

Just checking if grub control with imidacloprid is still available........I had heard it was taken off the market. Thanks.

Imidacloprid is still available here under various Bayer formulations. Formerly Merit. It is actually more a systemic insecticide than a grub controller. It is absorbed thru the roots and migrates up into the stems and leaves as opposed to Orthene which is applied to the leaves and migrates down into the bulbs or rhizomes. Orthene is now banned in my area.

Milky Spore is more a grub control used to eliminate a lot of different grubs.

I believe individual states can set the standards for insecticides and herbicides so products available here may not be sold elsewhere. Check garden centers at big box stores such as Lowe's or Menard's since they carry a large selection of those products.

I have heard good things about milky spore and I plant to try it, I have moles terrible.
I understand it is not harmful to fruits, veg or flowers or lawn and it can last for years in the soil.
I think might be a little pricey to put down, but will be worth it easily if it works.
any comments?

I use Merit for iris borer -- always put it down the day there are 2 days in a row of 70 degrees. Any earlier and it just doesn't work as well for some reason. In any case, it has almost completely eliminated them from my beds, although it has taken 3 years to do that.

Sue - Zone 6a