so I'm thinking of something that I can get that utilizes gravity to very slowly feed outdoor plants while I'm not around... Jorge C.'s grow dvd suggests just punching a hole in a watering tank but I don't mind spending a couple bucks and I'd hate to think that things watering away only to find out my plants went under-watered during a dry spell because it only has enough water pressure to continue dripping until it's like 2/3 full!

Anyway... is there any reason something like this wouldn't work outdoors? It's listed as an indoor watering product

Anyone know some alternative products?