Garden Bed Covers

I am still working on the layout for my first garden bed, but I will definitely be posting it next week!!  In the meantime, I could use some advice from anyone with experience in using garden bed covers.  I am hoping to use covers to help extend the growing season, and I have seen so many different options - but not the exact one that I want.  I have a few below that I like, but don't quite meet what I would like to do.  I will also do my best to explain what I am thinking about - if you have an opinion I would love to hear it!!  I need all the help I can get :)

 

The first thing I was thinking about is something like this:

 

Find the page here.

 

 I love the tidiness of the rollup covers and how the beds look in general.  My first reservation is that I want to have trellises on at least two of the boxes, which would make it hard to roll up the backside.  Also, my boxes are 10' long and I'm not sure I could roll the covers up over that length.

 

The next one I like is this one:

Find the page here.

This was another great option - and it even shows an irragation system - but it doesn't include the trellis in the cover like I was hoping. I also think it would be dificult to use once the trellis plants started growing - so no early starts for those veggies. However, this trellis looks like the one used in the Square Foot Gardening book and is very close to the one I plan to build. 

 

Finally, here is the third option:

 

Find the page here.

 

I like the look of these boxes as well, and it's getting a little closer to my idea.  The hoops are taller, but the trellises aren't the same as what I am planning to use.  I also worry that if we had a decent wind storm, the hoops would take the trellises out.

 

The trellis I plan to use is built using conduit and I thought it would maybe work if I used 4 way corners and fittings and have the flexible pvc pipes attach to the top of the trellis and connect to the boxes.  Since my trellis will be moved one foot into the box (like above), this will allow the cover to reach both sides.  Also, since my boxes are 10' long there will be 4 vertical supports.  I want to find a way to allow the cover to slide up and down the pipes without falling off  and to stop at any point along the way - I thought something like the plastic shower curtain rings might work if I can figure out how to hold them in place.  This will allow me to reach the plants inside without removing the whole thing - a huge plus for me! 

 

Does anyone have any experience making these?  Any advise on what to do (or not to do)?

 

Have a great day!

Beth