Why green or clear?
I suppose the green will act as shade cloth. If the sun beats down on the clear one, it would get really hot in there. The green will deflect a little light and it would get less hot. I have a similar cold-frame like this that I’ve had for years, and I’m tempted by this price. Mine cost around $100. They are great for hardening off seedlings.
How much wind can the walk-in clear ones handle? We get a lot of high winds in my area.
Hi, I am replying to your question from the OGrow company!
Our walk-in greenhouses are strong enough to withstand regular wind. We suggest you tie them down with the OGrow anchors to be sure it wont move from place once installed.
Thank you for asking 
Can we get an official response on how to choose between the green and clear coverings? I’m mainly going to grow fruit trees and shrubs. Would fruit trees do better with the clear covering because bit provides full sun?
Does the 5 Tier Gardenhouse come with a clear or a green plastic cover?
do the 4 tier or 5 tier greenhouses have casters/wheels?
None of our greenhouses are equipped with wheels yet. Your suggestion will be considered in the future!
Green, as you can see on the product image.
While we cannot determine which is better for the particular kind tree you are planting, we can advise you with some of the pros and cons regarding the Clear/PVC vs. PE greenhouse cover.
PVC: The plastic used on our clear covers generate extra heat and is better for cold climate area. Plants can be seen to add beauty to your garden!
PE: Customers and greenhouse experts prefer PE over PVC claiming that the PVC material contains a toxic load that can be damaging to sensitive plants. The PE material is made out of stronger elements, and protects from sun, for plants that do better with less exposure to the sun.
Good luck!
Just wondering why it’s more expensive on Woot than on the OGrow website? (although it’s “out of stock” on OGrow) It’s just $2 less but still . . .
Can we get additional/replacement covers for any of these structures? I purchased one of the 56" X 56" clear greenhouses, but would like to also have a green cover to use during especially hot summers.
Replacement covers for OGrow greenhouses will be available by 6/13/2014 on ogrow.com and other marketplaces.
Thanks!