Thought I was ok until today....(ok maybe in denial for a few weeks now but) today I dug a few things and definitely have borer...then dug a few more and found more...and more...and MORE. Ugh! looks like at least every clump has at least one borer! I am at a loss! No I did not take proper care of clean up last fall or this spring but didn't think it would be this bad this fast...did burn off a few that had not bolted to far by the time I thought of it....

So whats the best approach this late? Dig and drown? any other options?
I will not be using a systematic as the majority of my garden is for the bees. (although I see the appeal in this situation, I do not want them in my garden, and I think its to late for it to be effective at this point anyways.) I'm going to be looking for a source of nemitoads that sends to Canada...

So far I have dug a bunch up and put them into a bucket of water for hours to try to drown the borers...then replant...if there was anything left to hope for....
So far the plants important to me look ok or have the borer only on leaves thus far...

...and will be doing a much better clean up this fall and spring...
They are everywhere...I feel overrun!!
Ugh, ugh, UGH!

Well, digging , and the soaking are probably your best bet, at this point, I suppose. When you get 'em dug, do some 'surgery', to expose the worm, if you can. Generally, there will only be one borer in the rhizome, as they are cannibles.....and only the strong survive!.......because, if he's INSIDE the rhizome, soaking won't be able to get to him. Their "entrance" point is inside the leaf fan, and they don't exit until they are ready to pupate.

hmm....Most were still in the leaves...If I saw damage I would pull them apart and squish the buggers but sometimes it doesn't look like there is damage.

Would nematodes do any good at this stage??
I hate to spend the money getting some shipped if they would not be effective...

I think those are better in the spring--you just have to do what you are doing. If still in the leaves they are squshable, in the rhizome you have to did them out.

John saw a small buck deer in the garden yesterday. Nothing to do with borer, I know but another pest.

Too late for nematodes. Find and squish works well, better then drowning which is quite ineffective as Arlyn stated. Sometimes they are obvious in the fan so just need to press the leaves together and say adieu. When you find any in a rhizome just run a wire in the hole and the thing won't survive. Then let the wound air dry in the sun if possible. I leave a rhizome like that out of the ground with just roots in the soil for the rest of the summer most times. Ignoring the buggers will allow things to get worse as they go into their adult stage and lay eggs.

Yup, as Lucy says, if they are still in the leaves, you can squash them, or if you're not sure about that, you can fill a water pistol with a BT and water mix, and squirt it down ,inside the leaf folds. Although, BT DOES affect honeybee larva, as well. But , any "chemical" control, or any of several "natural " controls (like BT) will affect SOME aspect of the honey bees life cycle. Thing is, if there are no blooms to attract them, the bees won't be there, anyway.

What is BT?

Different Bt strains are specific to what species they effect, Bt aizawai is the only one listed as toxic to bees so I would stay away from it...but even so they have to ingest it so for this type of application its prity low risk. You definitely do have to know the risks of any control chemical or natural. I agree there is never anything with no side effects at all (just try to reduce the risks as much as possible). I hadn't heard of Bt used for these guys but will definitely look into this.

Jane Bt= Bacillus thuringiensis A bactera that when ingested by many insects produces a protein in that insects stomach that is toxic and thus kills the insect. Usually used for lepidoptera caterpillar control (often Gypsy Moth) or mosquito larva control (with a different subspecies ; Bti)

Thanks for the suggestions!
Wire into the hole is a great idea too! Was wondering how to get the buggers in there without destroying the whole rhizome.

A systematic will affect bees only if the plant is in bloom. If you use it on irises now, there is no bloom. Of course if you have mixed beds with blooming plants that would be an issue if you got the systemic close to it.

Research and experience shows applying it now is NOT EFFECTIVE. But even if I ignored that and tried:
Systematic means absorbed by the plant, incorporated into the plant. Forever.
Its CALLED SYSTEMATIC for a reason. I wish people would stop ignoring the fact it does NOT just disappear.

Besides research has shown the nemitode is much more effective (100% in field trials see summary online: http://www.cdn-iris.ca/borer.h... ) so if I WAS going to try something this late in the game I would go with the one with less negative side effects and much less persistence. Why would I settle for something so toxic, so wide rangingly negative AND not nearly as effective.