You have to replace the fertilizer strip every year with 2 fresh cups of fertilizer (I use a 10-10-10) and some fresh dolomite, but 50 pound bags of either are cheap...you can 'refresh' a LOT of Earth Boxes for about ten bucks. Replacing the mix is pricier, but you only do that every five years.
I have 46 different varieties of tomatoes in EB's right now, and they are ALL cranking. My wife's english cucumbers and bush beans are also going nuts in 'her' EB's.
Thanks. If we have some extra cash at the end of the year, I may just order some. I would like to use them indoors during the winter, and I think my daughters would like to use them, since they don’t have much space to garden.