We decided a few years ago to let this native plant take over a few patches in our flower beds.
I have not regretted the decision for one second.
It never has to be watered.
The tallest of the stalks are over 7 feet tall, creating a lovely mini forest.
I do wish us North Americans had a bit more imagination though, and called it by the name our British counterparts use... doesn't Rosebay Willowherb sound SO much more romantic than Fireweed?