I currently grow arrowroot, comfrey, lucerne, chickweed, nasturtiums, red amaranth, swine cress, cobbler’s pegs, and extra vegies (kale, spinach, lettuce, herbs, tomatoes, corn, etc) for our chooks, as well as scattering sprinkles of Clucker Tucker (from Green Harvest) in any bare areas.
I originally purchased packets of Clucker Tucker (seeds for barrel medic, bok choy, buchwheat, forage chicory, clover, cocksfoot, linseed, lucerne, millet, forage plantain, silverbeet, subclover and sunflower), amaranth and nasturtium seeds, and a box of arrowroot corms and comfrey root cuttings from Green Harvest, back when we first got chooks, in January 2010, and transferred the arrowroot and comfrey to our current place when we moved. The chickweed, swine cress and cobbler’s pegs, of course, reseeded themselves, but I also specifically help them along by spreading seed, or just moving them completely to a more appropriate spot if they pop up in areas where I don’t want them, such as the vegie patch.
The traditional definition of a ‘weed’ is “a plant that is growing in the wrong place/where you don’t want it”, but I would modify this definition to put a permaculture slant on it by saying “a weed is a plant with no beneficial uses”. And if you look at it that way, these ‘weeds’ aren’t really weeds, they are free food for the chooks, and many of them have other uses as well:
* comfrey1, which can be ‘weedy’ because it proliferates from root sections, so it’s hard to get it out of an area once it’s there, is also a ‘compost activator’ – its nitrogen content stimulates microbial decomposition, it’s a ‘nutrient accumulator’ – its roots are able to access and accumulate nutrients that other plants may have difficulty reaching, bringing them up and making them available through decomposition of the leaves, the leaves are generally high in potassium and other nutrients, so they’re also good as a mulch around fruiting trees and shrubs, and the leaves can also be made into a ‘comfrey tea’ to be used as a tonic for your plants, bees like the blue flowers, and the leaves and roots have any number of medicinal uses2 including as a muscle-relaxant for strained/over-tight muscles, sports injuries, RSI, etc (you can purchase comfrey cream from your chemist, or make it yourself). (WARNING: comfrey is now banned in Australia for internal use. Make sure you consult your medical professional before using.);
* bees also love lucerne flowers, the plant adds nitrogen to the soil while providing habitat for skinks, and the trimmings make a good mulch;
* arrowroot plants provide shade, provide habitat for skinks and other small critters, they have pretty red flowers for the bees and provide a cut-and-come-again source of mulch, while the corms help to break up clay/compacted soils and can also be eaten as a potato substitute (they’re much higher in starch though, so need to be soaked for a lot longer) or processed into flour (a gluten-free alternative to traditional wheat flour in baking, and corn flour as a thickening agent);
* chickweed and swine cress are nice in salads, as are nasturtiums; and
* nasturtium leaves also make a nice peppery pesto/dip, the flowers are edible and the honey bees LOVE them too.
So remember: “a weed is a plant with no beneficial uses” :)
1 For more info on comfrey, try the Permaculture Research Institute’s articles http://permaculturenews.org/2010/10/01/the-wonderful-multi-purpose-comfrey-plant/ and http://permaculturenews.org/2014/03/18/comfrey-really-improve-soil/ , https://en.wikipedia.org/wiki/Comfrey (it has a good list of references at the bottom) and any number of permaculture- and gardening-related books and publications.