This idea is one I will be doing with strawberries & lettuce. I saw it in a magazine - get guttering and attach it to what ever you have - along the wood deck or as with me, we will attach rows of plastic, new guttering along the back side of our garage.
I will add some water crystals and a few drain holes and put 3 or 4 rows up. I'm sure you can find good, used guttering, but since our building is new I want to get new so it's nice and neat. Keeps bunnies away too.
Kathy
