I am now tempted to try and grown cat nip but I'm not too sure mine need any encouragement to go more radge than they already are.
These are the shit, although a bit pricey. http://m.tigersheds.com/garden-sheds/wooden/potting/
I removed half of the roof timbers and most of one wall of our shed and replaced it with corrugated plastic to create a greenhouse/shed hybrid. Works well and very easily done.
What you growing?