Just occured to me I have an actual photo of my existing garden and patio. The portion of trellis you see is where I was thinking of putting the planter.

Thanks much!

Here is a link that might be useful:

Hi Alys.
What are you going to be using your cold frame for? I have several that are used for different purposes. First, I use a couple of cold frames for early greens. Lettuce and bunching onions, mostly. One is permanent, since I grow lettuce from early spring thru late fall. The tops come off when it is warmer. It is under a shade tree, so it gets full sun before the tree leafs out, but gets shade in the heat of summer.

Then there are my temporary cold frames. Those are the ones that I throw together right on top of the garden using bales of straw and the old shower doors that I saved. Those are for over-growth. There comes a time each spring, about 3-4 weeks before our last frost date that all my darling little seedlings outgrow the space I have under the lights and I just cannot stand dragging ~all~ those plants outside each morning and back in each night. The ones that are more cold-hardy go into those cold frames and they love it.

But in either case, 8 inches won't be high enough by a long shot, unless you are just using it to get a jump start on lettuces and will be removing the lid as it warms.

So, what ARE your plans for the cold frame?
Kay.

Thank you for responding, I think I was unclear. The "portable" one wouldn't be 8" high total, I was thinking I'd need about 6-8" of soil, the box would have to be taller than that, of course. My concern is that being off the ground, the soil will be too cold from the air underneath.

As to what I'd use it for, I was thinking starting seeds mainly and maybe growing things like lettuce, spinach etc, earlier and later. The more I think about it, the more I probably like the "permanent" box next to the trellis better. But, now I'm wondering if it will be too hot for lettuce and other leafy's there, even with the top off, on the concrete. That patio can get pretty hot as it faces east and that spot gets sun until about 5 p.m. This stuff is all trial and error for me given the spaces I have to work with.

Your spot for lettuce intrigues me. I never thought under a tree would work for any kind of veggies. I do have a spot next to the patio, in my second picture you can barely see it behind the curve of pavers and potted tomaotes, where currently two dead dogwoods stand that are coming out this spring. The neighbors hickory tree shades that area and I've never had any idea what would grow there, given that in the middle of the growing season it's fairly shady a good portion of the day.

Thanks again, I appreciate any advice.

Is there some reason you couldn't just make a removable cover for the main bed itself? Does the soil in the bed freeze in the winter? If you could make the trellis removable and the soil doesn't freeze, then you could make a cover for the bed and grow lettuces in there and also protect seedlings until time to plant out. I'm going to do that next year on some of my beds. This year I just did cheap cold frames on the ground.

You know, I hadn't given much thought to covering the garden bed itself, mostly because I figured it would be #1 too big and heavy and #2 too hard to store the cold frame during the summer months since I didn't want to do a plastic hoop-house, but perhaps I'm overthinking it. I don't have to cover the entire 4x7 space for what I want, I could just make a frame that sits inside the existing timbers, perhaps even break-down. I'll have to give that some more thought.

If you can find a copy of "The New Victory Garden", Bob has a plan for his and it breaks down. It may not be exactly what you want but it'll give you an idea or two.

I'm not sure if my cold frame plans will be of any help but here is the link.

Thanks everyone. I still haven't decided exactly what to do, but I appreciate the ideas and have some stuff to think about.

I don't think I got an answer to my first question though - will putting the cold-frame up on casters, instead of having it sit on the ground, make the soil too cold if the soil is about 8" deep? I'm thinking of using it for greens (lettuce/spinach) and for starting seeds.

Thanks again!
Alys

Gee I don't know but you could bury heating cable in the bed and plug it in at night. I bet you have an exterior plug on that patio.

Yes, I could do that. Where would I buy that? I'd love to try to keep growing fresh veggies for salads, etc. later in the year and I don't have space for any kind of actual greenhouse.