We have a large collection of silphiums at JLBG, but unfortunately most have limited garden value since they splay apart and often completely fall over when in flower. While they’re loved by native bees, we have been frustrated to not find many that are mainstream garden worthy. One that has been impressive in our trials, however, is the southeast US native whorled rosinweed, Silphium trifoliatum var. latifolium. These 15 year-old clumps at JLBG, which originated from Scott County, Mississippi are now 6-7′ tall, and quite garden worthy. Hardiness Zone 5a-8b, at least.