Looks to me like the buckwheat is also strong enough to keep out all kinds of weeds, including grasses. I wonder if this is a good method to use when one doesn't want to turn over the soil and instead use the non dig method of gardening. I sometimes use creepers like sedum to take over an area, wander for ages then rip it up to sow with something I really wanted. The sedum goes into the compost and is good and wet enough to rot up on one season and doesn't have seeds that come back from the soil.
I too am going to put in some seeds which can grow in colder weather. My zone is 5 so it'll have to be winter wheat. Soil is sandy and acidic because I have lots of pine trees and the yield of veg was poor. I want the beige soil to look black and retain water, especially from the competition from all the tree roots and in prep for a repeat in 2011 of those hot dry weeks we went through this past summer.
Comfrey is not easy to come by, so I wonder if buckwheat would be better. Sometimes old cupboard cleanup beans and seeds might do as a replacement.
