Whether you call them volunteers, self-sowers, or (like me) welcome weeds, desirable plants that helpfully fill up the bare spots are an important element of a gardener’s garden. They usually start with just a plant or two that’s been intentionally introduced and then allowed to set seed, though sometimes seed can be broadcast for the purpose. Others might be wildflowers from neighboring areas. They are generally not an element of “landscapes”, as they can disrupt the tidy look of pruned plants surrounded by wide margins of mulch.
I grew up in gardens that use these plants. My grandmother’s garden always had johnny-jump-ups springing up everywhere, and forget-me-nots in the shadier areas. She also welcomed black-eyed Susans, which eventually took over the garden as she eventually narrowed her focus to just the rose garden and the dahlias.
My mother’s garden has had a parade of these plants over the years. Early on we had celandine poppies, columbine, a variegated oregano, and feverfew filling the gaps between the daylily collection. Later Lunaria, lemon balm, and two species of tobacco joined in. Butterfly weed, Echinacea, Euphorbia, Ruellia, and Patrina found their spots as well, and more recently European gingers and Japanese painted ferns have begun colonizing the garden as it becomes shadier in the way mature gardens do.
Here on the farm my welcome weeds have included Johnny-jump-up, feverfew, Agastache, perennial bachelor’s buttons, woodland tobacco, blackeyed Susan, and summer phlox. I’ve also welcomed the fleabanes, grass-leaved goldenrod, ironweed, asters, blue lobelias, and Joe Pye weeds that migrate in from the meadows.
One thing we’ve learned from this multi-generational experiment is to only welcome weeds that are easy to pull should you decide that you don’t want them anymore, or want to keep them confined to certain areas. The Ruellia and the painted ferns, for example, both reached a “critical mass” at some point and started coming up everywhere, which turned out to be a real problem because both plants are very hard to remove once established.