Shallow and narrow raised bed ideas?

To pin down my blow away greenhouse, I've secured the bottom few inches of the cover by sandwiching it in wood and then staking that wood down. Then buried it with earth.

To stop said earth from simply spilling away, I've retained it with a plank of wood, so now I have what is in effect a shallow (about 6 inch deep) and narrow (about a foot wide) raised bed.

It seems a shame to not grow something in it, and there are of course plenty of things I could put there, but I wondered if anyone has any excellent ideas?

I thought about carrots and lettuce and a few annual flowers, but I'm totally open to suggestions.

 

Could you stand some pots on it? Bottomless pots perhaps (so they can, also, root-through). The old fashioned Tomato ring-culture pots perhaps?


http://www.thegardensuperstore.co.uk/acatalog/tomato-ring-culture-plant-pots.html

 

I've filled it with onion sets now.

 

I have some water containers (you know the sort you get a cup of water from, the blue plastic things) I have a few of them I have drill holes in the bottom for drainage, I have yet to cut the tops off them (and I suppose I could use the tops as mini greenhouses

 

Also useful for watering. 2L plastic bottle, cut the bottom off, place upside down (original spout downwards) and put a cane in, through the spout to hold it in place. Fill the "bottle" with water and it will flow out at a slow-ish rate and percolate into the ground rather than run-off or evaporate from the surface.

If it all runs out the sides at the bottom of the spout push it into the ground, obviously, but also adding a handful of stone-free soil in the bottle will mean that the next fill will gum it up in the spout and slow down the rate of percolation.