I have a peace lily that I kept outside over the summer, and brought in in the fall (Ontario). I am continually finding fairly large (0.2 - 1 cm) new holes in the leaves, but I can't find any pests on it. There are no eggs or other marks on the leaves, and the plant is otherwise healthy. Could it be a nocturnal slug that's hiding in the soil? Any other guesses? And how can I get rid of whatever is eating it?

Welcome to ATP

I would bet it is a slug. Just get some slug bait (there are organic types if you want) and sprinkle a very tiny amount on the soil surface then moisten it with a spray bottle or gentle stream of water to make it attractive.

Those little beggars hide down in the pot, or way down between the leaves in the daytime.

Just to cover the bases, though, do inspect the undersides of the leaves very closely to see if maybe there is a little caterpillar or something else that might be the culprit.

ps. please go into your profile (top left of the page in the blue area, the little person icon) and add your general location so we can have a better idea what kind of critters you may have in that pot?

Probably whatever it is, is nocturnal, or you would have seen it.

Maybe get up in the middle of the night and sneak up on the plant with a flashlight. That will give you the satisfaction of being the Mighty Hunter as well as decisively identifying and eliminating the problem.

You could rule out flying insects with some sticky tape (like packing tape) or by draping shade cloth or organza fabric or bobbinet over the plant, and tucking the edges under the pot to keep insects away.

Ontario ... do you have many slugs there? It does sound like a #%**^## slug. But if you don't already have a box of slug bait handy, you must not have very MANY slugs.

Maybe give the potting mix a very thorough watering by immersing it in the sink or a bucket. Give it a few minutes and see if anything comes rushing up from the soil to keep from drowning. Like that scene in "Alien".

Maybe do that, or drench thoroughly with diluted hydrogen peroxide. It might discourage some eggs or help the slug decide to vacate. I wouldn't go much stronger than 0.3% H2O2 (3 ounces of drugstore peroxide in one quart of water).

However - if drainage in your potting mix is not excellent, "dunking" or drenching might make the mix so wet that it can't breath well enough, and root hairs could drown. I wouldn't water it much more heavily than your experience already says is OK.

Or, just possibly, letting the mix get VERY dry between waterings might also motivate the slug to go looking for a moister home. Like a small bowl of cheap beer you set beside the plant. Slugs are like frat boys: they go where the beer is.

If you're growing the daylily in "soil" rather than a soilless mix, you might consider re-potting, knocking soil off the roots as you go and even root-pruning if the pot is root-bound. Replacing the soil would also let you eliminate any pests bigger than an ant.

P.S. We don't really need it, but a photo is always fun.

Peace lily, I think @RickCorey . Surely nobody would bring a daylily indoors in winter? Unless they'r e in Alaska . .??

Ahh, thanks.

My two volunteer lilies live outdoor year-round (Hardiness Zone 8b) and I've never grown a daylily. From what you said, they must be very cold-hardy.

I've been told one of my lilies is this:
Lily (Lilium 'Black Out')
and it sure looks right.

Very oddly, I see very few slug-holes on those lilies, even though I'll very rarely see a slug climbing the stem like it was a Magic Beanstalk and the slug wanted to meet the Giant.

Yeah, dayliles are mostly very hardy perennials. We have trouble with slugs or snails on daylilies in my daughter's garden in Salt Lake. They don't eat the leaves, but climb the stems and eat the flowers.

Peace lily is Spathyphyllum which is a tender tropical, and I don't think, strictly speaking, it's really a "lily" at all. But then neither are daylilies. (Hemerocallis, not Lilium like yours)

But who knows what an accursed slug will eat??

dyzzypyxxy said:But who knows what an accursed slug will eat??

Everything but concrete. And they slime that up!