Monday, July 2, 2012

Cutworm Damage

Usually if you see little holes in all of your hosta it is slug damage, but this year it has been way to dry for slugs.  You would think this would be great news for the hosta lovers, but a different pest has decided that hostas are very tasty this year, the cutworm.  Cutworms have always been around, but I think the mild winter we had allowed more of them to survive.  If your hosta look like this:

You probably have cutworms.  If you are still not sure, find a hosta that has large holes in it like the ones above, and check the petioles at the very base of the plant.  You may find the worms hiding there.  You can also scratch the surface of the soil under the hosta (by the base) and you will find them there.  They are brownish or greenish colored worms.  Cutworms like all kinds of plants, not just hosta.  So even if you are not a hosta lover, you may have seen them eating your veggie or other perennial plants this year.  The Wisconsin Farmers are also fighting with the cutworm outbreak.

So what can you do about cutworms?  The truth is there is not a lot you can do unless you want to use some harsh chemicals on your plants (and even then most only work on contact).  The cutworm are only in the garden from May into early July.  Then they turn into small grey colored moths which do not affect your plants.  So if you can wait the cycle out, the hosta should be getting their second flush of leaves and you can pick off the most damaged leaves.  Some people put cardboard or tinfoil collars around their plants to try to prevent cutworms.  You can also go out at night and pick the cutworms off of your plants and dispose of them.

2 comments:

Anonymous said...

You could have a few other easy options for cutworms that wouldn't involve chemicals...

Diatomaceous earth is relatively inexpensive. You can sprinkle it right around the base of hostas in areas showing damage.

Adding a few birdbaths around the garden will bring in more birds, especially during times as dry as now, and birds eat bugs. Win, win.

I had to relocate one birdbath away from a large hosta, as the birds tended to leave droppings below the rim.

Beneficial nematodes supposedly like cutworms, though I haven't tried them. I don't know how you feel about links, so I'll just say that the big catalog/website that specializes in organic controls sells them. G@@gle can fill in the blank.

Nothing wrong with waiting them out, though.

C.

Hosta Nerd said...

Thanks for the other tips! I had also heard organic sprays with spinosad in them will take care of cutworms. But spinosad is very harmful for bees, so I don't use it.