When early pioneers were rolling their way across the tall grass prairies of North America, sometimes, in mid summer, they would come across a towering plant with huge basal leaves that often were oriented on a north-south axis. They called it a Compass Plant. In later years scientists speculated the leaves point that way to protect themselves from the burning sun. The plant would be labelled Silphium laciniatum – the same genus as the Cup Plant (Silphium perfoliatum) that I wrote about earlier.
It’s easy to see why – they’re both really tall (the Compass Plant can grow to 12 feet high) and both has relatively small (2″ – 4″) sunflower-like flowers. Carious types of bees love to feed in the flowers and their stalks, if left up all winter, can provide over-wintering refuge for beneficial insects as well. They differ in that the Cup Plant likes moist meadows and tolerate flooding in spring while the Compass Plant, being native to the prairie, likes it dry and can tolerate drought. (After next to no rain during last year’s spring and summer drought, they’ve back in my dry back field more vigorous than ever.)
This is likely because Compass Plants have a really long taproot (up to 16′ deep in the prairies!) that seeks out moisture, even in the rocky, decidedly non-prairie like soil of the County. This root can, unfortunately, make it really challenging to transplant – best to start seeds and plant them where they can stay for many years. They can self-seed but it’s not a fast process – my 15 year old patch has produced only three offspring that I know of, two in the gravelly rocky area where the ‘parents’ live and one in a meadow, about 30 feet away. One plant with a single flowering stalk can, however, become one plant with multiple flowering stalks.
If you can find Compass Plant for sale (perhaps at a local native plant nursery) and you have room, buy it; or, if you find seeds somewhere (Seedy Saturdays in Picton or Trenton possibly) , try starting them yourself. (Read up on how to prepare them for sowing first.)