Hi--here are my 2 cents:

By all means use logs from the dead tree as walls, but be aware that all sorts of creepy crawly bugs may come to feast on the dead wood..and then meander into your garden. I've used left over wood "chips" from winter wood delivery to line my garden path and I do think they draw ants.

I've got similar shade/sun issues. I'm not sure if you're going for veg garden or perennial. In either case, make sure to put the shade lovers where it gets the least sun. I find I can grow tomatoes and peppers (notorious sun lovers) in 6 hours sun...but they don't yield as much. I put lettuce and spinach and other shade lovers in spots that get the least light and they thrive.

No size guidelines but I"d suggest using the "Lasagna method" for starting your bed. No pre-digging or sod removal necessary. Basically lay down pads of newspaper and cardboard (several inches thick) wet them well (so they don't blow around) and then add layers of chopped leaves, compost, grass clippings, garden trimmings, manure, etc. Try googling "lasagna method" for more tips.

Have fun!

Amy

A nursery bed is a great idea for growing on small woody plants and perennials.

If I understand your plan, this will be a raised, level area terraced into a slope; the sides will be built up using the trunk of a fallen tree - you gave us the height but not the diameter of the trunk - with the uphill side not raised much and the downhill side raised more.

A trunk can make good sides for a bed, IMHO. It will last for years and when it begins to rot can be replaced with something else if the bed is still needed. Washout may be a problem if the trunk isn't really uniform, if it leaves gaps between the surrounding soil and the (presumably enriched) soil in the bed. This is especially important on a slope, where water wants to run downhill.

You can prevent this being a problem by digging the trunk slightly into the ground; the undisturbed ground along the outside of the trunk should be able to hold, and you can make sure to compact it if it's already disturbed as long as it has not lost its structural hold on the slope. Depending on the steepness of the slope, you might need to insert a barrier between the soil in the bed and the trunk; rolled-up sections of "weed barrier" cloth is great for this because it's flexible and will conform to the contour of the land. Water WILL flow downhill, so you need to accommodate it - you can't stop it but you can stop it from taking soil with it.

Of course you need to think about the water actually undermining the trunk too, if the slope is long and steep, and that's a more serious problem. Redirecting water using a series of rocks and/or runnels uphill from this structure would be a good idea in that case.

Morning sun is really good for most plants, as it evaporates dew and prevents susceptible plants from getting things like fungus and mildew. It's also less harsh and will not scorch or wilt plants that prefer some shade.

If your only option is morning shade and afternoon sun, you'll be a bit more limited in what will do well in this bed. If this is the only place that's available, it will still be useful, but it's not ideal. The shed itself will block breezes and rain water, as well as sun, so bear that in mind when planning what to grow in this bed. There's a lot of work involved in building a successful nursery bed, and it makes sense to place it in an ideal exposure if you can.

I'll add my thots too, tho they are worth what you are paying for them....

I have a multi-year history of killing baby shrubs in the garden when I lose track of them, kids trample them, tree guys molest them, they get mowed, whatever! So I, too, just started a nursery bed a couple of weeks ago. I kept mine to 4' wide, as I can reach into the middle from either side relatively easily. This is the width often recommended for raised beds. I would think 6' would make it hard to access the middle without walking thru the bed.

I've given each baby about a square foot -- thinking that I want to transplant them to more permanent spots while they are still relatively small -- some of them in a year or so, some of them in 2 or 3 years, depending on rate of growth. For me, it's easier to move smaller plants, and I think they settle in more quickly. But juveniles might not get trampled, uprooted, etc., as often as babies?

For soil, I did used a combo of clay and leaf mold. I thought about adding vermiculite or sand for drainage, but finally opted not to. This part I still worry about. I am growing natives and ultimately concluded that they won't be growing in open, loose soil when I plant them out, so I thot I would start them without those conditions. This may be a fatal flaw, tho!

Re: sun. I agree with a preference for morning sun, afternoon shade. I think mine get a bit of each. Probably more shade than they'd like. That said, I think sun is important to flowering, not so much to root growth, and they are to young to flower anyway!

I think your rotting tree sounds like lovely food for your growing plants. Do, by all means, use it! Unless you can leave the snag standing, which is really wonderful for bringing beneficial insects and birds to your garden....

Keep us posted with how your thinking evolves.

ML

Thanks for all the great advice. We were actually able to get a neighbor to cut the tree down today! Woo Hoo! The top 1/2 was infested with bugs (termites maybe) but the bottom looks great. It was a birch. As long as there is no evidence of bugs, it's okay to use still, right? It's not big enough to make the whole bed now, even if I make it more narrow, so I need to rethink the sides but it's a great start. Once we have some sunshine, I'll reassess location. I may be underestimating how long it takes the sun to hit that area. I hope not because it's the best spot for the bed.
The slope isn't overly steep and if the trees can be used short term, then I'm okay with replacing them with something else in the future, if I need to. I think it can withstand the run off we get.
I intend to make this as a perennial and shrub breeding ground, not veggies.
Thanks again. I feel much better about the plans that had been swirling around my head!
Chris

Hi again.

If you opt for more traditional raised beds (tho I love your tree idea and am not worried about insects attacking your healthy babies -- I think they just thrive on rotting wood), check out the link below.

I've just ordered 2 beds from them. They are a home-based business, as far as I can tell, and their product is made in western MA. It's the least expensive bed I've found -- but I think/hope the quality will be terrific.

Prior to this, I've made beds using corners from Gardeners Supply and pine from Home Depot (they don't carry cedar). Those were hard to assemble, and the pine is pretty well rotted, tho only about 3 years old. I've also ordered and assembled GS's cedar bed kit. Boy was that expensive! And not that easy for me -- tho I lack most DIY talents.... I hope they last better than my silly pine experiment. But mostly I hope that the new raised beds I link to below will be the perfect thing!

Good luck!
ML

Here is a link that might be useful: Less expensive source for cedar beds