I tried setting out a saucer of beer, but no sign of slugs. This is an indoor planter, so I don't know how any slugs got there.

if its indoor.. why did you use soil and wood indoors...

you should have.. or int he future.. remove it all.. and find or make a good potting medium..

AND STERILIZE IT BEFORE YOU USE IT...

https://tipnut.com/sterilize-soil/

get a flashlight.. and look after dark.. and see what crawling around...

your plants alos look a bout etoliated.. a plant light to increase light would probably help ..

ken

Slugs are repelled by mints and not likely to be found munching on them. I suggest that there’s a caterpillar lurking in the loose potting mix during the day and coming out to feed at night. Which is EXACTLY what some species of cutworms do.

Where did you get that potting medium and what kind is it? I’ll bet that if you carefully rake around plants with a table fork, not too deeply, you might unearth a sleeping, curled up brown or gray caterpillar. Do this is the daylight.

Thank you all!

Briefly, that section of the planter was used by my late cat as a litter box. Even two years afterwards, the ammonia smell was very noticable, especially when I watered the plants that used to be there. I dug out as much as I could and replaced it with "Mr. Garden Topsoil" (because it was cheap and I needed a lot and didn't want to waste nice potting soil if I couldn't get rid of the smell) and stuck som mint in there, hoping that the mint would spread and discourage any future cat from going there.

Starting soon, the planter will be getting intense sun (hence the curtain in one picture). I think the plants are leggy because when I rooted them in water I kept them out of any direct light.

So, I'm not really growing the mint for any culinary purpose; it's just a placeholder until I can figure out what to do permently. The other side of the planter has two Osmanthus fragrans that are 6' tall and provide some nice privacy from anyone walking by..

I thought I remembered that slugs don't like mint, so maybe there's a cute caterpillar that will tun into a lovely butterfly (or a moth that will eat my winter coat).

I'm rarely up after dark, but I get up around 4am and will sneak out there, flashlight in hand!

Thanks again!

PS to Ken. This planter runs along one side of a glassed in breezeway that connects the house with the garage. The breezeway isn't really used as a room of the house, more as a place to put plants in the winter.