Oops! I mistakenly told some of my potential customers at Powell River’s Fall Fair that buckwheat can be planted in the fall. Not true. The end of August is generally the last available time for it to be planted. And it will be killed by frost.
So, if planning to use this as a cover crop or to add some organic matter to the soil, it takes about four weeks to flower and you can dig it under at any point. Not a bad idea to let it flower for a few days and give those bees a little fun and then dig it under the soil. Alternatively, you can cut the above soil parts down and put in the compost pile and then just turn under the remaining nubs sticking out of the soil. Buckwheat will break down in the soil very rapidly. In general however, it’s not bad practice to wait two to three weeks before planting anything else in the same location.