I have about 75 hostas in my yard and all of them seem to have some kind of insect problem (in addition to the slug and rabbit problems evident in the photos). Something is eating vertical holes (don't go all the way through) in the stems of the leaves. This causes the leaf to weaken and fall over, eventually dying. Would slugs do this? There are a lot of visible spider nets at the base of the plants too but they seem too obvious to be mites. I have asked at two greenhouses and they are stumped. I have put down Sluggo once and sprayed them all with an organic fungicide/miticide/insecticide once and am due for another application. Please advise! Thank you
Stearns County Minnesota
I think the blemishes on the stems are from a fungal disease and the holes are from slugs. I put down a heavy application of slug killer early in the season before the hostas even leaf out and again as soon as I see damage. Check the label for how long an application of slug killer lasts, I think it is weeks not an entire season. There is a good covering of mulch under the hosta in the picture and this is good for weed and moisture control but is is also good habitat for slugs. Please check out the link for common diseases and pests.