My plant wall has two systems. The wall itself is a drip system. The nutrients drip down the roots. The gutter, however, is a flood and drain system.
This morning I was catching up on posts on WindowFarms and read a post by Ed where he has modified the bottle window farm into a flood and drain system. Brilliant! His post caused me to look at my wall and evaluate its health/growth in comparison to the plants in the gutter.
The begonia in the gutter is faster growing with more flower stalks and bigger leaves. That’s pretty definite as far as supporting evidence goes.
So the moral here is, if it’s food you’re interested in growing, flood and drain is going to be more efficient/effective.