I wish you lived close. I have some very well decomposed compost. I would share.

Johnny

oldokie, if you have the opportunity to get a load of compost, you could just sheet mulch it. In this way it would be ready to plant and you can let the soil build itself.

Another option is to double dig. You can get by with 1 sq ft or 2 sq ft at a time where you dig in your kitchen scraps and some browns. Then, back fill the dirt. Cover with cardboard and keep moist, like compost moist. When you have more kitchen scraps, dig another foot or 2 and do the same. If you have clay, this is the fastest way to amend soil. The bugs and microbe processing the kitchen scraps do the work for you.

Another option is to ready the soil sufficient to sprout cover crops. Loosen it up a bit. Seed. Water in. Let those cover crops grow. Pick something regenerating, like Austrian peas where you can chop and drop all winter long. Just let the cut material die on top of the surface. You can plant some of your winter greens and vegetables among them. Sometimes the plants will follow the roots of the cover crop helping them grow deep when they cannot break the soil themselves.

To keep it simple, build your raised bed by justing add organic matter to the existing soil. It doesn't matter what you add----homemade compost, bagged/purchased compost, mushroom compost, chopped/shredded autumn leaves, old spoiled hay (if you know it doesn't contain herbicide residue), even finely shredded bark/humus (I buy it in bags where it is labeled as Soil Conditioner)---just whatever you can find that will simultaneously improve the soil's capacity to both drain well and to hold moisture. If you don't want to work the organic matter into the soil, do what Bon suggested and just put it on top of the existing soil. Over time, the organic matter gets carried down into the soil in many ways---via the action of your trowel when you plant, via watering, and via earth-burrowing creatures like beetles and earthworms. You don't have to do anything fancy.

I did a lot of double digging in my front garden, but not until I'd been growing things in it for a few years and already had improved the soil a lot. When we first moved here, you couldn't break up the dense, compacted clay more than 1-2" deep even with a powerful rear-tine tiller so double digging at that point was out of the question. We were in drought and the clay was like concrete. I had to be patient and work with the soil for about a decade before I could finally double dig it myself with a shovel, but eventually I did true double digging where you dig out two shovel depths and amend to that depth. In 1999 it was unimaginable that we ever would be ever to double-dig that clay, but now I can double dig the soil beneath any raised bed easily. Since the raised bed above grade level sits atop double-dug soil, most of my plants now are growing in triple-dug soil. It only took us almost two decades to get the soil improved that much. It might not take you nearly as long because maybe your clay isn't a badly compacted as our was, but patience and not expecting it all to happen in the first year or two definitely pays off.

Even in the early years long before the soil was good enough to double-dig, we got great results---even in the first year or two when there really wasn't that much organic matter in the soil yet and it wasn't yet deep in the soil. It is just that every year the yields and plant health got better and better. And, from the viewpoint of the garden, every year it became easier and easier to plant and to weed because the clay was easier to work with.

When I pull weeds, as long as they haven't gone to seed, I don't even bother carrying them to the compost pile anymore. Why bother? I just lay them on top of the ground as mulch and let them decompose in place. It might not look beautiful, but the weeds decompose right there in place, releasing nutrients into the soil as they do so. It is the most efficient method of soil improvement I've ever done. Sometimes I think people get carried away and make it harder than it has to be.

And, here's one warning about raised beds inside a greenhouse. My cats thought that I was building them big litter boxes inside a nice, warm greenhouse. I ditched the idea of greenhouse raised beds after that, moved the improved soil to the garden, and went back to growing in containers in the greenhouse. The cats have been yelled at enough that they know to stay out of containers, but it is a lot harder to keep them out of raised beds. My cats largely are kept out of the fenced garden now for the same reason. It has an 8' fence and gates I keep closed to keep them out. It is easier for me than letting them come into the garden and then having to chase them out to keep them from using the raised beds there as litter boxes. If you don't have cats, it won't be an issue, unless your neighbor has cats. Our neighbor's cats come over and play with our cats, so I kinda have to pick and choose my battles since there's always cats around and underfoot. I just could't imagine fighting to keep the cats out of the greenhouse's raised beds all winter long because I need to keep the doors and vents open so the greenhouse doesn't overheat on sunny days.

Composting inside a greenhouse can work, as long as you have good air flow, but a compost pile inside a greenhouse can attract field mice and voles (and possums, skunks, squirrels and other little animals) to the greenhouse if you're putting kitchen scraps on your compost pile. For that reason, i don't compost inside the greenhouse.

Dawn