Shallow planting?

What can I plant in a shallow container? Was given container 1mx1m but only about 10-12 cm deep. Would this be suitable for moving garlic into or is it too shallow for that?
Also if I grew spring onions in it, what kind of beasties could I expect to have to ward off? Last year i grew spring onions in the greenhouse so had no problems with slugs.The containers are too big to raise on a table or chair and too flexible to move about. Wondering if I was given them as they're useless for edible growing

 

Probably a bit shallow for Garlic really, but Radish would I think grow well in it. Try mounding up the soil in the middle so it's like a mini hill, grow lettuce in the middle and radish around the outside. But keep a good eye on the watering as it will dry out quickly.

Steve...