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

I've heard all the horror stories about running bamboo that took over entire neighborhoods and ate small pets and children. I normally only growth things I can eat. I've never cared for bamboo shoots, so I never noticed what the nursery charges for pots of bamboo. I guess I assumed the nurseries put one pot of it in the back end of the shadehouse with some empty containers of potting mix and prayed that the next morning it wouldn't have spread to the parking lot and begun to sprout up through the asphalt. (grin) Seriously, I've always loved the look of bamboo, but never grown it myself to know much about it. Thanks, Greg

There are many variables to be considered in a discussion about soils. I'll tell you a little about 3 different soils & you can decide how different they are and if you think compaction/soil collapse will be a problem for you. Peat based soils, like MG, break down quickly - within a single growing season. When you use them, you have to hope the container size and o/a plant mass is enough to compensate for the collapse toward the end of summer. Hopefully, the roots have colonized the container and the planting has matured to the degree that the plant is able to use the water from compacted soils quickly enough to avoid root rot. We hope that roots are healthy enough that they actually become a part of the structure of the soil and function as aids to the soils ability to hold air. For maximun vitality when using these soils, the plant should be bare-rooted every year. Conifer bark-based soils break down at a rate around 1/4 that of peat soils. They virtually guarantee that the roots will become a part of the soil structure w/o much concern for root rot, as long as your irrigation practices are reasonable. The 5:1:1 mix of pine bark:peat:perlite is a good example of this type of soil, and there are hundreds of GW folks growing in it with very good results. You should expect at least 2 years service from this soil, as opposed to 1 from those based on peat. Your trees should have some attention paid to their roots every two years - 3 years maximum, so this is a good soil to use for your trees. The third type of soil is the gritty mix described way upthread. It consists of equal parts by volume - pine or fir bark:Turface:crushed granite. It is 2/3 inert, so it breaks down very slowly and will still be very serviceable long past the time appropriate for you to do a repot/root-pruning. This soil retains its structure for a very long time, and could easily be pressed into 5 years service if the plant's becoming badly root bound before that wasn't a consideration. Clay pots (or other containers that have gas-permeable walls) will always be healthier for your plants - no matter which soil you choose. The price you pay is the need to water more frequently, but that act of watering drives damaging CO2 from soils and brings in a fresh load of air - greatly beneficial to plants, both. Can a clay pot help compensate for a collapsing soil? Yes, to some degree it can. Roots begin to die only a few hours after being deprived of adequate aeration. The small and most important roots die first - then progressively larger roots until air again returns to the soil, allowing the plant to start a rejuvenation process. This cyclic death and regeneration of roots due to collapsed soil is very taxing from a stored energy perspective. The plant uses it's reserves or current photosynthate (food) production to regenerate roots. This means less increase in mass in other organs - including fruit. How the clay pot helps is by allowing air back into the root zone quicker, so not as many roots die when using a soil too water retentive. Al

Compaction is probably not the main worry about the vermiculite, especially in a light mix like Mel's Mix made "by the book." It will eventually "break down" into smaller particles, which is why Mel says to start with the coarsest grade you can find. Over all it will last a long time and make a major contribution to your soil quality. Not only will perlite not do the same task, but perlite will add its nasty texture to your soil, making it unpleasant to handle (which is a very un-SFG thing, as one of the fundamentals of SFG is that you work on your SFG and handle your soil some every day). Perlite will also float to the top of your bed, at which point it will either wash away or sit there not providing any benefit at all to the consistency of your soil. I have no idea about the bark, I would wonder if it is even more acidic than the peat, which wouldn't be a good thing. I don't have any especial love for peat either (although it is worth noting that it is being generated in Canada faster than it is being harvested, and is indeed a renewable resource) but it does seem to result in a soil mix, built by Mel's formula, that was excellent from the very start for growing vegetables and flowers. If I were to make any changes in future boxes I might cut down on or leave out the peat, but my soil formula would alway contain at least 1/3 vermiculite if possible, due to my experience in the pre-raised bed days of the first SFG book, where vermiculite was by far the best addition I made to my native soil, producing better results, that showed quickly and lasted longer, than any of the other stuff we added over the course of many years. In my raised SFG I plan to add a little vermiculite and a lot of fresh compost every year.