Julie - is the bottom of the planter in contact with the earth, so there is continuity between the soil INSIDE the planter and the earth. If so, I would use a high % of mineral soil and then about 25% organic ingredients like finished compost, reed/sedge peat, partially composted PBFs. I'm not getting a clear picture of what you're doing, or I'd be more specific. If the planter is isolated from the soil, I'd apply what you've learned about container soils and go with something like the 5:1:1 mix, or the gritty mix.

Al

Hi Al,
The circumference , say 6" along the outer edge, of the planter will have some soil contact. This is where I assume the roots will head to get past the solid fir stump until the stump rots. The remainder of the planter will be the surface of the fir stump. It sounds like I should use mineral soil and compost. Thanks!

Great idea for taking out a stump! I might use this one.

thanks emgardener :) I will be bolting together about 11 - 24"x 24" long pieces of metal roofing in order to make a wall around the stump. I may also build a much smaller planter and set it in the large planeter for a terraced look. I also considered a wall of poly bags/tubes filled with soil and piled around stump but they would take a lot more space because the first course would need to be pretty wide across the bottom to support a 24" wall. Also could use blocks but the roofing is cheaper and SO much lighter :)The roofing comes in so many colors but I'm shooting for the rusty look which will not be hard to achieve in the Pacific NW.

As I read your post you will end up with a raised bed 24 inches high and seven feet diameter around the existing stump. This will give you 12 inches of soil over the stump which should be plenty for most plantings. My orchard here was carved out of the Douglas Fir woods and the stumps were left and the orchard planted around the stumps. Nothing was done to remove or cause the stumps to rot. The stumps were about 3 feed high and took 40 years to rot away in the weather by themselves. Al

Hi Al,
40 years!!! It's amazing how long lived wood can be unless you've used it for a deck :) I hope that having the stump covered by dirt will speed up the process.
Julie

Julie - you can GREATLY reduce the amount of time it will take for the stump to rot if you drill large holes in the cut part and fill them with KNO3 (potassium nitrate), urea or high N granulated fertilizer, like you might put on a lawn (27-3-3 is a common one). If the stump is more than a foot tall, drill holes in the perimeter, too, angled down and toward the center, and fill those as well. All that N will cause the microorganism population in the dead wood to explode and they'll all be happily munching on the wood.

Al

Al,
Should I do this and then wait a period of time before I fill the planter with dirt/plants or just pile on the soil and let critters go for it?
Thanks!
Julie

I'd do it and then add the soil.

Al

thanks Al