Thalictrum 2011

[RickR]

And I grow both those species well, but my Elin died!

[AmyO]

Does anyone have a remedy short of nuking them for the little catarpillars that completley defoliate my T. rochebrunianum? They also do a number on all my Aquilegia. I've started using systemic granules to see if that will do the trick.

[RickR]

I have plenty of problems with insect defoliation of aquilegia, but never had anything eat any of my thalictrum species or hybrids to the point of devastation, like they do with aquilegia.  In fact, they are one of the most pest free plants in the garden!

I just went out and took a poll in the garden.  These have absolutely no leaf insect damage in the shade garden:
T. kiusianum
T. thalictroides
T. flavum
T. dasycarpum
T. rochebrunianum Lavender Mist
T. filamentosum
T. ichangense

I also have T. aquilegifolium that is in full sun (don't ask me why 'cause I don't know).  About a tenth of it's leaves have part(s) eaten.

I'm sure we would all be interested in learning the results of your use of the systemic granules.  Any preliminary conclusions?

[Lori S.]

In previous gardening areas, if the leaves were being eaten by caterpillars that work outside the leaf, or even by leafminers, I found that manual squashing worked well... pretty satisfying too, if they are really bothersome. 

[Hoy]

I never experience defoliation of Thalictrums or Aquilegias. They are among the healthier plants here.
So is Astranta major. But I am at the lookout of something that can defoliate this one as it has become a pest plant in my garden >

[AmyO]

The defoliation happened earlier in the season and the plants have releafed out with flowers...the Aquilegia were worse, but are recovering now. I only treated the plants in pots and cut back all existing foliage. So I'll keep you up to speed if there is something good to report.
I'm using Marathon which is not available to the general public and can only be ordered through a wholesale nursery supplier, but I've been told that Bayer brand rose & flower systemic works really well on lily leaf beetles and other nasty critters, so it may work for these insects as well.

[Lori S.]

So is Astranta major. But I am at the lookout of something that can defoliate this one as it has become a pest plant in my garden >

Well, there's always the old tried-and-true method of weeding...    It's cheap, effective and herbicide-free.  What is 90% or more of gardening anyway but weeding?