Could be grasshoppers. They make round holes.

That's what I thought it looked like - but I have never seen a grasshopper here... could it be slugs or snails?

I think it might be slugs and snails, I do see tracks in the AM. There are fewer since we had the ivy ripped out on the other side of our fence but the property is still full of ivy and the snails that live in it. I have heard that a saucer of beer is a good nontoxic way to get rid of these pests, I'll try that. I prefer not to use chemicals. Maybe a can of cooking oil for good measure to get any earwigs too (shudder, I hate those things).

The aphids I only see on the sun parasol and not on the sages or lavenders.

When I find lots of holes in leaves, no chewing on the edges, I usually suspect Flea Beetles. Al

Sluggo is a good choice- it's non-toxic and works well with slugs and snails. If you get rats in your neighborhood they will eat all of the snails. Something to look forward to :D

I did re-examine the leaves today more carefully and there are no bugs or other things currently on them, so something is coming at night and eating them but not living on the plant. The poor plant is tattered beyond belief though! I wonder why this plant is being targeted so directly, it must taste good. I have 2 more in a window basket which are fine but likely out of reach of these bugaboos.

I haven't had time to deal with the garden while working on my kitchen, I noticed the orange aphids on my sun parasol while painting kitchen cabinet doors on the patio (got a nice close up of them as I was leaning over painting). But I haven't been able to do anything about them yet as the plant is behind all the freshly partially-painted cabinet doors... garden will require some attention this weekend!

Never heard of flea beetles. My leaves are VERY tattered. There is some sort of residue left behind, and the holes are pinhole sized. I live in Seattle.

Velveteena, go out at night with a flashlight. You will find out who is to blame.