peppers, propogators and polytunnels

This is the first year that I have had all three. My peppers have germinated and are in my new vitapod propagator. Outside I have a raised 8' x 4' bed with a PVC fitted cover. My question is when can I move the peppers from propagator to polytunnel. The vitapod is a large propagator with a height extension so size wont be a problem. The seed packet says move outside in early summer. How much earlier can i move them under my cover?

Excellent idea. Should I get one with a hygrometer as well?

Excellent idea. Should I get one with a hygrometer as well?

I've never used one of those     

Wavertree red

Here are pictures of a 4' x 4' bed. Mine is twice the size but looks the same except it has got 3 hoops not 2.

http://www.harrodhorticultural.com/HarrodSite/search/product/Plant+Protection_Crop+protection+tunnels+and+hoops/GNE-103.htm

hope that this helps

Ideas, ideas.  I can feel the staple gun coming out again.

Cheers Grubbypaws.