if i remember right you cut it just above the knuckle. but you can test it to make sure. i mean its not like there is a shortage of those reeds, they are a invasive species after all. very cool of you to make mason bee nestsWe are going down to the lake tomorrow and getting reeds to make mason bee nest. Has anyone else made them and if so are they hollow all the way through or do you cut the reed just above a knuckle?