In our area, Buckerfield's, Borden Merchantile and Integrity stock them. If you don't have time to make alfalfa tea, you can still sprinke alfalfa pellets on the ground in the Spring - however the nutrients will take much longer to be released, it doesn't look as attractive, and the pellets can attract rodents. A better solution would be to use Complete Organic mix and add extra alfalfa meal to it, then scratch it into the surface of the soil. Orchid and rose growers use alfalfa tea as a foliar spray. If you grow delphiniums and irises, they also love alfalfa tea.
Some iris growers mulch their beds with alfalfa meal.
And an additional benefit for delphiniums is that the Epsom salts in the tea help to ward off slugs and snails. Position it in an out of the way place - you don't want to have to move it once it's full. Let stand for one week until it bubbles with fermentation. Your nose will tell you that it's ready. Stop applying it in the fall, when you want the plants to start hardening off for the winter, and don't want to encourage soft new growth.