The first year I grew bee balm (Monarda didyma), a variety called ‘Raspberry Wine’, it was a fantastic success. The tiny, little plant I started with expanded politely to about a foot and a half across and stood 3 feet tall, with many lovely flowers. The leaves had a minty, spicy scent and not a speck of disease. It was a hummingbird magnet, too; every evening we could count on watching a couple of the little birds squabbling for control of the flowers.
The following year, the polite expansion continued, a little less politely. By the end of that season, the patch was four feet across and barreling over a rose and 2 daylilies. The flower stalks had grown to 4 feet tall and the nightly battle among the hummingbirds had taken on tones of a World War 2 dogfight. Scrappy little critters, those hummingbirds.
The third year began my annual battle to keep bee balm under control. After a few experiments, I decided the only way to control it was to lift the entire patch every other year first thing in the spring, cut out the old, woody growth and replant a piece from the expanding edge. This got to be a somewhat brutal affair as there was a great deal of viable plant material left at the end. I tried giving the pieces away for a while but people began to avoid me; you’d have thought I was giving away excess summer squash. I wouldn’t get around to that till August.
What I couldn’t give away got composted or at least hit the pile. There’s now a lovely patch of bee balm surrounding the compost bins and Brian mows it down when it gets too rowdy.
Every gardener has their own way of dealing with thugs. Some enjoy their rampancy, giving them their own space to pillage, some limit them to pots, and others refuse to grow them at all. A lot depends on the particular plant, too. Is it worth the effort to accommodate? Is it a major thug or just a minor hooligan? If you do let it loose in the garden, can you get it out again without high explosives?