Since we got our guinea pigs a couple of weeks ago, I've been feeding them most of their greens from what I have in the winter vegetable garden: collard greens, chard, and parsley. I also some sugar pea volunteers (that came up from the peas I planted this spring), and since there's not enough of them to really have peas for the winter, I've been pulling up the vines and feeding them to the pigs too.
Just this limited experience so far makes me think that it would make a lot of sense to plant things this spring that the guinea pigs would enjoy. I'm thinking carrots -- do the pigs eat the tops as well as the root? Beets maybe? I like beets and beet greens, but we could share these with the pigs. Lettuce maybe for sure, but I have to be vigilent to prevent the slugs from getting to it first. Radish tops? Spinach always seems to bolt on me, but maybe the guinea pigs wouldn't mind bolted spinach. Other ideas for the garden?
I live in the Sunset Zone 5 (not sure what that is in the USDA system) in the Pacific Northwest, which is similar in climate to the UK.