WOW! You plan to fill your beds with bags of soil????' We go to the soil place or the landscaping yard to get truck loads at a time! Granted, after you fill you raised beds, you just have to top them off with some compost and lovely fill from year to year. Back to your origional idea of how many beds and how large, do you have to do them ALL this year? That's a LOT of work! I started with one (too large) bed and added one per year, sometimes 2. Added compost and soil each year as needed. My origional bed lasted 8 years before the gophers got in and this year we are re-doing it to include an herb garden and fountain. Next year will be the addition of fruit trees. I think what I'm saying is take it small (unless you are really young, have tons of money and time, a tractor would be helpful! And, why not, a crew of gardeners!!) Woo Hoo Have fun! Nancy

If you suspect your soil is not good, just mix up a potting soil and fill the boxes with that. In any case it is not a bad idea to begin this way, as it removes one variable. A simple formula is one part peat moss, one part perlite, and one part good compost. You don't have to be all that exact about it. Mix it a little at a time in the box, or mix it on a tarp and then shovel it in. If possible, mix a variety of types of compost. Some landfill places give away free composted solid waste from the sewage plant. I wouldn't trust that stuff, because a lot of bad stuff goes into the sewers. A 4 x 4 box one foot deep is 16 cubic feet. So you would want something over 5 cubic feet each of peat moss, perlite, and compost. If you have gophers, in your area, make sure you staple half-inch hardware cloth to the bottom of the box, or you will regret not doing it later.

You're right about the chips robbing the soil of nitrogen. Depending on what you're growing it might work. On the container forum they discuss a blend of pine bark + other ingredients. A load of the sawdust piled up & mixed with a green like grass clippings or plant waste will be good to add to your soils about a year if you turn it now & then. Sometimes, manures come with sawdust bedding, so that is a good combination to compost for further use. What kind of plants would this new raised bed be for growing? Are you filling a new bed or topping off an existing bed? A sandy loam topsoil mix + 6" organic matter would be a good way to go if you need to plant right away in this bed. Use compost or composted manures and mulch with dried grass clippings, shredded leaves, chopped straw, used coffee grounds, etc. If you're growing vegetables, you also might want to add some pumice like you said and a complete organic fertilizer. Over time you won't need as much fertilizer to grow great vegetables. Each year continue to add more organic matter to build the soil you want to use for your gardening. It takes a lot of it to keep up the soil, so it's nice to build some home compost piles for a good supply. You could also compost in place in & around your existing vegetation in perennial or shrub beds. I'm in western WA and we also have glatial till, so that when you dig a hole you get a pile of rocks. Those rocks are moved elsewhere in our landscape. Eventually the annual vegetable bed areas have become good soil for our perennial fruits like raspberries and strawberries. Our technique has varied over the years, but usually we've sheet mulched with manures and bedding in the fall piling up to 12" on a bed then turned in the spring. Plant & mulch. By summer's end it's shrunk again, so more sheet mulching. It's amazing how much organic matter is used up. In my garden boxes with wooden sides I also add compost whenever I harvest a crop then replant. In fall apply manures, used coffee grounds, and lime. In spring I've done different things different years depending on my energy level. Remove mulch to the sides before planting transplants. Rake smoothish & plant. Turn over with garden fork, rake & plant. For direct sowing seeds I rake a bit more later in spring or cover with a slight layer of screened compost to smooth out the bed. It always seems to work. For perennial and shrub mixed borders we just mounded the soil with the layers of compost ingredients and after a few months planted through the layers. We've spread mulch 2x a year since and those are much easier to work beds. Where we had existing vegetation that soil is still quite hard & rocky. As I move things around I come upon that rocky slippery stuff and add a lot more compost to a section when replanting. I hope that helps ~ Corrine

If your native soil is truly sandy it might work OK, but I've found that although my native soil works great in the garden, it is a complete disaster once I use it in any amount in a pot or raised bed (or the compost pile for that matter). This is due to the clay content. Now I make my own potting soil with volcanic scoria (cinder) mixed roughly 60/40 with some fluffy organic material such as compost. It works really well for me and is basically free, since I make the compost myself, and collect the scoria from a nearby volcanic hillside. Without that much compost you could use peat or some inexpensive compost available by the truckload. I think you'll have better results if you avoid anything loosely called "topsoil" since this can often be bare mineral soil with no organic matter, lots of caliche, and a high clay content.