Absolutely everything goes dormant here in the summer, and then again in winter, and of course the weeds are the first things to green up in. Clover seems to hang on a little longer than other stuff, maybe.
There are so many types of clover. Some are better for forage, but others flower really well and attract bugs. There are even "micro" or "mini" clovers that can be planted in place of lawns, which could be really great for people who want to "pasture" their chickens in a more urban setting.
Clover seed is grown in the Willamette Valley, so there is an Oregon Clover Commission. Their website has some general info about different types of clover ... I wish it had more detailed information on each specific variety.
http://www.oregonclover.org/
This link has a little more user-friendly listing of different varieties of clover, and it's a seed catalog.
http://www.outsidepride.com/seed/clover-seed/
I would think if a person wants to try a good type of clover/pasture mix for their specific area, they could get some advice from their local Extension Service. This link can help people in the USA with that.
http://www.csrees.usda.gov/Extension/
Older poultry books, which presumed pastured birds, describe poultry pasture as "clover pasture." One of the great things about clover, besides the higher protein content, is that it doesn't get wound up in the crop of the bird like grasses can.
This PDF has a section on forages ... starts on page 12.
Profitable Poultry - Sustainable Agriculture Research and Education
It only has a tiny amount of info, but from two good sources with experience pasturing both meat and laying birds ...
"Joel Salatin has established what he calls a “permanent
polyculture” of clovers and grasses in his pastures,
with varieties of native grasses, broadleaves, clovers,
chicories, oats and rye that mature at different times of
the season. His chickens will “eat almost anything as long
as it’s not too tall and not too tough,” he said.
"Oregon egg producer Robert Plamondon has found
that pasture research from the early 1900s still applies.
“Everything I’ve read points to oats as the ideal coolseason
green feed,” he said, “while ladino clover, alfalfa
and, to a lesser extent, other clovers are better summer
feeds. My own experience with oats has been very favorable.”
So ... if you're seeding a seasonal pasture in the Pacific Northwest, oat for winter!
A related note about clover ... I know they make hay from clover, and I have even occasionally seen references to clover pellets. I was trying to source some, because I use ground/pelleted hay in my Fermented Feed mixture, and would prefer to use something with a higher protein content than Timothy hay pellets, but it needs to be something that has no potentiality for GMOs (so not alfalfa). My current approach to avoiding GMOs in my feed is to completely avoid GMO crops ... too much fraud to trust anything else, IMO. I'm having no joy in sourcing clover meal or pellets. Does anyone have a line on that?