Once again I am thrilled to see so many other owners of spoiled chickens, doing their thing. I see I am good company! I started sprouting grains early on with my chicks when I saw them gobbling up sprouted seeds under leaf piles in the yard. I also noticed them eating the millet and sunflower seedlings growing up out of a place where I had been throwing birdseed for them.
I sprout all kinds of grains, and do allow the sprouts to get longer than the ones we humans eat, even to the greening-up stage if I'm really slow. I am fascinated by the idea of still being able to grow ancient grains, and just for fun have tried sprouting things like emmer and kamut. Mostly I rotate among oats, wheat (hard red and soft white), barley and rye. I plan to try lentils, quinoa, millet, rice and corn soon. I buy seeds from the bulk foods section at Whole Foods or our other wonderful locally-owned natural foods store.
The easiest way to decide if something will sprout is to ask: is it a seed I could plant in the garden? In other words, split peas obviously won't grow because they have been broken in half. Shelled sunflowers have had their protective seed coverings removed. So think like a gardener. And someone has already said, if the seed doesn't sprout, you can still give it to the chickens, as long as it is only soaked, and not starting to rot.
I have also been trying to grow greens in my small greenhouse for winter, but it is slow (the greenhouse is unheated) and the girls absolutely demolish the whole tray within 10 minutes, right down to the roots. I have tried the 'hang a cabbage in their run for entertainment and winter greens' trick, but my chickens are only so-so about cabbage. What they love above all else is fresh kale ....... which is in short supply this time of year. I have established a rotating set of greens trays and use wheat, rye (sprouts the fastest) and oats. I use plastic plant flats or round flat planters. I feel it is vital they get some greens this time of year, when there isn't much greenery out there, especially under the snow.