This is being a very helpful thread. We recently acquired acreage, in Oregon’s Williamette valley area, that has large patches of broom. We are considering using broom that we cut as fill material in a hugelkultur. At question is how deep to bury it to minimize risk of introducing broom in pasture areas where the hugelkultur will be located. Does anyone have experience with this.? P.S. we would be cutting prior to seed production, but I notice that there are seed pods from previous years that is still attached or otherwise tangled in the branches of the broom stands - hence my concern.