Control of Arum italicum

[Gene Mirro]

They are coming up everywhere.  The bulbs are very deep.  I'll destroy a lot of good plants if I try to dig them out.  Is there an herbicide that works?  I've tried Roundup.  It doesn't work.  Maybe the waxy leaves don't absorb it, as is the case with ivy.

Those of you who can't grow it should be grateful.

[Margaret]

I've had trouble with this for many years but have almost managed to eradicate it by means of weeding out every single arum leaf as soon as it appears. I only find the occasional small leaf now because the corms are so weakened. Good luck with yours!

I've had less success with Acanthus spinosus 'Spinosissimus using the same principle. It's a thug of the first order.

[Ezeiza]

Gene, it is a weed with me as well. Roundup spraying of foliage does little harm. Pulling the leaves and praying the wounds in the stalks seems to do better. That is, removing the blades and part of the stems and applying Roundup on the wounds.

In open spaces, digging the whole plant with tubers when it has sprouted and the soil is soft from rain is effective.

What Margaret mentions, that is, continual removal of the foliage is possibly the solution as this gradually weakens the rootstock enormously. The worst damage is when the foliage is well developed and removed. 

[Claire Cockcroft]

Hi, Gene,

You have my sympathy.  A few years ago, I moved a small patch of Arum italicum out of a "good" garden bed and into a neglected part of the garden.  It thrives there.  But it took me about 3 years after that to remove all the corms that were missed in the initial move.

Right now I have a problem with Camassia leichtlinii that I planted by accident in one of my flower beds.  I naively thought I could just dig the bulbs to give away and that would be that.  The bulbs sprouted everywhere, mixing with autumn gentians and self-seeded dachtylorhizas.  For the last 2 years I've been cutting every stem below the surface as soon as I spot it.  This spring the remaining bulbs finally look like they're starting to be depleted.  I might win yet!