This was mentioned on The Survival Podcast today and I think it's worth mentioning, especially in the context of small scale or urban permaculture design.

Here's a PDF covering the basic design elements of the keyhole bed

More on keyhole bed design, this one from Florida : http://www.urbanoasisproject.o...

I really like the keyhole garden concept. The only reason why I haven't made one yet is because they are fairly small, so I went with the mandala shape instead.

Maybe this year I'll make a keyhole bed somewhere so I can get better acquainted with the idea.

I never thought of using metal cans as layering in a garden bed. I don't eat anything out of cans, but my dogs do-- so I have a lot of them that I put in the trash to be hauled away by the city.

Has anyone done this. Do the cans disintegrate?

I wondered that myself. The old type of cans would deteriorate and I would think they would add iron to the soil. The newer type (aluminum?) that is common in pet food cans would be doubtful.

I've been reading a lot about the keyhole gardens and am intrigued. Lots of good info and links out there.
If we have continuing drought, I will wish I had established a few.

Garden tour: keyhole and other permaculture features.

http://www.youtube.com/watch?v...

I like that herb spiral.

If you know the author of this video, please ask him to rotate it to landscape mode so we can see more than 2 inches of the video.

The plant he's calling an eggplant is actually a Datura.

Its a YouTube video from Appalachian organics. If that eggplant is datura, I hope that little farmer there doesn't eat it! I remember graduate students who spent many an evening smoking it, but I would hate to see that little guy wind up that way! I notice Milkmood has already been there suggesting conversion to landscape mode.

He's going to wonder why his eggplant has huge white blooms that leave behind spiny fruits! Hopefully he won't try to eat the fruits or he'll have a similar experience to the graduate students you remember.

I never saw so many super-smart guys enjoy getting stupid.