Climate change is making Chicago autumns warmer and drier, which means that our pollinators are entering hibernation later than ever before, so it is important that we plant and nurture the last flowers of the season.
Red Stem typically plants a mix of flowers that bloom from April through October or November, so if you have one of our gardens you will most likely have asters still in bloom. Asters are far and away the most prolific late-season flowers, and provide critical food for pollinators. In many forest preserves and restored prairies in the area, the many types of aster fill vast swathes with purple, blue and white flowers. The Frost Aster (Symphyotrichum pilosum)is the latest blooming of all, it’s tiny white flowers still fresh and full well into November.
Unfortunately, asters can be very aggressive in a small garden, and we need to use caution when planting them lest our gardens also become a wall of asters. At Red Stem, we usually start with only one or two in a garden to ensure that other plants are able to compete. Fortunately, there are other late season flowers that we use to extend the season for our pollinators.
Several species of Black-eyed Susans bloom late into the fall, including Rudbeckia hirtaand R. subtomentosa.
Bottle Gentian, Gentiana andrewsii,with its strange and elegant bottle-shaped blue flowers, is a favorite of bumblebees.
Ohio Goldenrod’s cheerful yellow flowers persist long after most goldenrod species get gray and downy with seedheads.
Our one fall-blooming tree, the Common Witchhazel, can bloom well into early winter, their narrow petals only unfurling on warm days, when the hardiest bees, moths and flies visit them.
Written by Liz Olney
Sources:
https://extension.umn.edu/yard-and-garden-news/blue-gentian-favorite-late-fall-bloomer-bumble-bees
https://www.grownativemass.org/Great-Resources/Gems-from-our-eNews/The-Pollination-Puzzle-of-American-Witch-Hazel
Photo credits: Red Stem Staff
