Delphinium

The little watsits get in pots as well, they leap up in hanging baskets too!

I grew all my delphs from seed, but I used nematodes and that kept them off.

I sowed delphinium seeds last October and they have come on great in pots.

 I use old copper pipe which I have cut into 1" sections which I place on the compost in the pot. Plant the seed in the centre of the hoop and grow as normal. When you transplant, allow the copper to stay on the young plant. It can be left there for years. Slugs and snails get an electric charge from the copper and they back off. As long as the copper ring/hoop is about 2 inches across, the plant will be fine and not choked, and it can establish really well before the slugs can get too it. I have used this with my Delphiniums for years and have crackin plants every year 

It works brilliant. I have them round the top of my hosta pots as well as all my veg seeds and they didnt much a leaf. First year I have had hostas fully intact 

The copper tape is so expensive and I found the old piping in a skip. Im all for cheap, Your flowers and veg can be a 'Slug Free Domain'

I would advise that they would be one per pot. Not sure about them staying in pots though Hoc...I have only ever brought them on in pots the planted out