You should be able to find edamame seeds in packages for a dollar or two at most any garden center. Many of the major seed companies have included them on their racks the past couple of years. Specifically, I've seen them on the racks put out by Lake Valley Seed Co., Thompson & Morgan, Ferry Morse, Botanical Interests, and I am pretty sure the larger Burpee racks will have them. Try looking at local garden centers with better seed racks and also at big box stores like Home Depot or Lowes.

If not, there are all kind of mail order companies that selll them in various sizes. I'd try Kitizawa Seed Company in California, Evergreen YH Seeds also in CA, or perhaps Johnny's Selected Seeds in Maine or Stokes Seeds in New York state, Territorial Seed Company in the PNW (Oregon or Washington, can't remember) All should sell them.

Barley - in small quantities I'd buy it from a local organic market which sells it for sprouting, or from someone like Johnny's, Territorial, or SproutPeople in San Francisco. On the barley, probably the minimum you can buy is about a pound. Which will probably run you something like $12 with shipping. Which is why I'd try to buy local first.

And yes, you could definitely grow a little of both in pots -- pick something a decent size, like at least 14-16 inches across. Use a really good quality soilless potting mix. Full sun for both crops. Edamame take about 70/80 days to produce a crop. They all ripen at once. You can freeze the excess after blanching them in boiling water or the microwave.

I don't know anything about barley tea, so I don't know if you are looking for foliage, seeds, the straw. Anyway, from planting to harvest of barley grain is probably about a 90 day process, give or take. Will depend on lots of factors, weather, etc. If you make the tea from the green foliage, that could be ready in like a week or two (like wheatgrass for juicing).

I guess you are trying to make mugi-cha, roasted barley tea? I love that stuff. let me know how it goes, please. I bought the edamame seeds, but never planted them. Now, I'd like to grow soy beans that I can ferment or just use for tofu. But, those are big dreams.