Cumberpach wrote:
around the outside.
snip
To protect outdoor tomatoes from slugs, I cut the bottoms off the plant pots
and then half bury the pots in the soil. I then put a thin one inch wide
layer of vaseline/petrolium jelly, around the outside rim. Slugs and snails
wont cross it. Replenish every 3 weeks.

Or copper tape. They won't cross that either.

--
Mark Allison, SQL Server MVP
http://www.markallison.co.uk