This is a really easy solution to be ably to winter over plants.

Those are great! I like the "staple a 2x2 to the long edges" idea.

Is the first tunnel sunken below grade somewhat, for better insulation? That sounds really effective, if you can get away with it. I think you must have good drainage. In most of my yard I could only do that on a slope, with slit trenches leading downslope, for drainage. Otherwise: mud wallow.

Rick, I have superior drainage, except for my bog area where everything drains to. That entire lower area stays wet even after months of drought. So where the cold frame was in the photos and where the tunnels were has very good drainage. For the cold frames I often use leaves and grass clippings or compost to insulate the sides, for the tunnels they were just left out in the open most of the time, when really cold weather was expected I used bagged leaves or threw a cover over them.

I like the idea of using bags of leaves as insulation!

I seem to have some kind of drainage fetish and I'd find a low, boggy spot a continual challenge. But if you have a big enough space that you don't need to use every square foot for beds, maybe having the variety is a good thing.

My very first drainage project ever reminded me that (as we all know, even me), water runs downhill. However (which I had forgotten), then it STAYS right there unless you give it an exit path to an even lower spot.







P.S. That bag of "Soil Pep" is the worst soil conditioner I ever bought, made or imagined. It was mostly coarse wood chips, and created an ugly solid mass of fungus when I buried too much in one bed. The nitrogen deficit probably contributed to nothing growing well that year in that bed. It is, at best, an adequate mulch.

After hauling in hundreds of truck loads (my toyota pickup) of leaves and grass clippings my bog area paths were still too wet to walk on most of the time. I have built the level of the bog up several feet over the past few years, that is right, several feet. It was still too boggy, so I used some discarded pallets I picked up and made a short path out of them, reminded me of the old sidewalks you see in the muddy streets of old western movies. Then I added mulch on top, it took several applications before it had the effect I wanted, solid footing without sinking. The first few layers would slide on the wood but as the layers built up they became firm. Then I found a lot of boards by the road, looked like someone had redone a deck maybe with lots of steps. So I used those boards to make more walk ways like I did with the pallets, covered them also and now the pathways are doing great. Hope to be able to do the rest of the pathways down in the bog like that eventually. Don't know how long it will take the boards to rot or what the effect will be when they do, I am hoping the paths will have firmed up by then and not go back to being spongy and soggy.

Seedfork said:...
I have built the level of the bog up several feet over the past few years, that is right, several feet.

I'm really impressed! You must have access to a lot of leaves and clippings, and a lot of energy!

I would probably have excavated soil from the bog onto the tops of the paths, wasting the boggy topsoil and never achieved several feet of height difference.

Your method gave you walkable paths. Even if they do eventually decompose, you'll have added huge amounts of OM to that bog. My understanding is that bogs tend not to be very aerobic, so the OM should stop decaying once it sinks,

Then you'll basically have a big "compost mine" available.

Those boards should last longer than anything else. Maybe divert future green grass clippings to your compost bins, and only put wood and brown leaves on the paths.

Maybe a power shovel or bulldozer could turn it into a pond plus a border of drier, higher soil, if you ever want a pond more than a bog.