This fall, we’ve experienced unseasonably high temperatures at the Chicago Botanic Garden, and our plants have taken notice. The average first frost date for our area (Zone 6a as of 2023) is October 15, and snow has been known to occur on Halloween. This year, though, temperatures have frequently remained in the 70s in September, the 60s in October, and the 50s through mid-November. This balmy deviation from the norm is hard to ignore, as are the plants that have capitalized on these favorable conditions.
Several genera are known to peak during late summer and fall, including species of ironweed (Vernonia), aster (Symphyotrichum), goldenrod (Solidago), and toad lily (Tricyrtis). A myriad of other common garden plants, especially trees, shrubs, and grasses, display a medley of colors as they prepare to lie dormant for the coming months. Who doesn’t love the crimson of a Japanese maple (Acer japonicum) or the rainbow tones showcased by little bluestem (Schizachyrium scoparium) once summer has passed? Like everyone else, I’ve always enjoyed this medley, but with it comes a sense of foreboding for what follows. In our area, this entails four or five months of frigid temperatures and dull, cloudy days.
Seeking and savoring the cultivars that have kept their momentum from summer through fall has been rewarding. While the following are undoubtedly beyond their peak form of the year, each does not vary significantly from how it looked in the prior months. They have remained surprisingly green and now seem more vibrant when next to other plants that have turned yellow, red, or brown, or have shed their leaves altogether. And to be clear, these are not your typical fall performers surrendering gracefully to winter. Rather, these are brutes, admirably plowing through fall with dogged resilience until winter forces their hands. I think these are worth growing for both their typical performance and what they have demonstrated these past few months, and I’m looking forward to planting some in my home garden next year.
Learn more below; all photos in the slideshow above were taken on Nov. 14, 2024.
Abelia ‘Peach Perfection’
While abelias commonly have bloom periods that stretch from summer to early fall, this cultivar has been more persistent than others, blooming well into November. The yellow-green foliage may appear to be succumbing to cooler temperatures, but it is now greener than it was during the summer months, when leaves were more orange-yellow. These factors combine to give ‘Peach Perfection’ a particularly vivacious presence late in the season.
Bergenia ‘Bressingham White’
During the fall and winter months, Bergenia leaves commonly turn some form of red, ranging from bronze to deep burgundy. This change is certainly welcome, especially given the large paddle-shaped leaves. But for now, ‘Bressingham White’ remains as green as it did back in early summer, with no signs of changing. In November, the green was even more pronounced once the coppery foliage of the nearby bald cypress (Taxodium distichum) rained down on it.
Buddleja ‘Pink Cascade II’
In our Buddleja trial, cultivars are typically at peak bloom in the month of August. Seeing panicles of bright pink flowers three months later when even fall-blooming plants have subsided has been a pleasant surprise. These panicles, along with the abundance of silvery white young leaves, suggest that ‘Pink Cascade II’ won’t stop until a hard frost makes it. Even if there are no pollinators to enjoy the flowers and fragrance, there are plenty of people who do.
Phlox ‘Early Bird’
Given just how early this cultivar bloomed this year (late March) due to our unusually warm spring, it’s amazing that ‘Early Bird’ still looks as sharp as it does. This is likely owing to the evergreen nature of P. subulata in its background, but the species and its hybrid cultivars do not all overwinter with the same aplomb. Only in mid-November am I beginning to see some foliage taking on silver and yellow notes. Between this evergreen nature and the fine, prickly texture of the foliage, ‘Early Bird’ is doing its best impression of a groundcover conifer but has the added bonus of a bright floral display in early spring.
Thalictrum minus ‘Adiantifolium’
It would be foolish to assume this cultivar is a pushover due to its petite size. For me, it has only grown about 1 foot tall and wide. Between this and its inconspicuous flowers, most people may overlook it altogether in a garden walkthrough. But those with a keen eye will appreciate the feathery foliage, which somehow resembles that of both a columbine and a fern. This is especially true at a time of year when other meadow-rues have called it a year and gone dormant. Throw in the occasional remontant flowers and this cultivar greatly outperforms its stature.
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The Unexpected Plant Overachievers of This Fall