Late Bloomers by Carole Ottesen

When cool nights and shorter days signal the arrival of fall, a few special perennials keep on blooming.

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Plant lust does not go unpunished. Hortigluttons are condemned to the circle of hell reserved for those who lusted overmuch after plants. In recent years, swarms of tormentors—mosquitoes and gnats—have made being in the garden in summer a torture unless one is properly armored against these insects. And being armored against them—a hat, a coating of citronella oil or, worse, a highly unfashionable net bag to cover the face, and long pants and long shirt—is itself a torture if the day is hot, which it always is.

Gardening during this period—which lasts from the first 80-degree day in May until sometime in September for me here in the Mid-Atlantic—boils down to choosing between sweltering or the itch of dozens of insect bites, gritting my teeth and doing what has to be done, and longing for that fine day in September when, the mosquitoes and gnats, having accomplished their evolutionary destiny, whatever that may be, mercifully disappear.

When that blessed day arrives, the best revenge is to have acquired even more plants, but to have stocked up on those that bloom late in the season. Fortunately, there is no dearth of late bloomers from which to choose. Some of the most welcome are those whose late summer appearance heralds the approach of relief.

Harbingers of Fall

When turtlehead (Chelone spp.) starts to bloom, you know that summer’s half way mark is past and fall is just around the corner. These wildflowers, native to creek banks and other moist-to-wet places in eastern North America, adapt well to ordinary garden soil and grow well in sun or part shade. The plant is upright to about three feet with very dark green leaves. The flowers range from white (Chelone glabra), pale pink (C. obliqua), or hot pink (C. lyonii ‘Hot Lips’). All are well adapted to USDA Zones 3 to 9 and AHS Zones 9 to 3.

Children love them because, as with snapdragons, squeezing the flowers will force open the “mouth.” But turtleheads are much more terrifying than snapdragons. Squeezing their heads reveals the turtle’s sickled fangs. Butterflies, including the Baltimore checkerspot, are not deterred by the threatening mouth parts and flock to the flowers. Deer usually ignore the plants and the flowers are good for cutting.
Another wildlife plant that blooms on the cusp between August and September is obedient plant (Physostegia virginiana, Zones 4–5, 8–3). Native to much of eastern and central North America, it must have been named by the same wag who christened Greenland. Wildly disobedient, it refuses to stay in place, but erupts naughtily via rhizomes to form great colonies—which is less surprising when you learn it is a member of the mint family.

But, in the right place, excessive growth can be an advantage. Let obedient plant loose in the sunny, boggy places that are the undoing of other plants and enjoy the erect, two-foot stalks of pink snapdragon flowers that this plant carries with geometric precision. The flowers are freely produced for more than a month and are great for cutting (in fact, you may want to deadhead them to avoid self-sowing).
Several cultivars are available, including ones with white flowers (‘Summer Snow’) and variegated leaves (‘Variegata’). Or plant one of the truly “obedient” cultivars: ‘Miss Manners’, a stay-put, clumping form with white flowers; or ‘Vivid’, a compact, later-blooming selection that has claret-pink flowers.

Wayside beauties

Obedient plants attract hummingbirds, but it is long-tongued bees and butterflies that search out the deep, rich purple flowers of New York ironweed (Vernonia noveboracensis, Zones 4–8, 8–3). An attention riveter on roadsides in the fall—and named the 1995 Plant of the Year by the Virginia Native Plant Society—this plant has yet to receive the attention it deserves.

The flowers, which open in August and continue into September, would be reason enough to grow it, but other attributes render it a must-have. Nothing bothers it. A tough, upright stem, celebrated in the common name, keeps it from needing staking and an equally tough constitution precludes trouble of any kind, provided ironweed is grown in mostly sun and moist, but well-drained soil.

Native, despite its name, to much of the eastern United States, New York ironweed responds to site conditions. Abundantly rich soil and moisture can produce a nine-foot giant. Ordinary conditions will produce a husky six-footer. If height is a problem, ironweed can be lopped back in June. This not only controls size, but tends to delay bloom.

Other ironweeds worth considering include giant ironweed (V. gigantea), a Kentucky native that typically reaches seven or eight feet. The Missouri (V. missurica) and western (V. baldwinii) ironweeds top off at about four feet. All attract such butterflies as swallowtails, whites, sulfurs, monarchs, and painted ladies.
Unfortunately, while these species are sometimes available through native plant sales and through seed exchanges such as the North American Rock Garden Society’s, you are unlikely to find them at the garden center. One that is more readily available is the smooth ironweed (V. fasciculata), a four-to-six-foot-tall plant that offers bright red flowers in late summer through early fall.


Photo credits: Obedient plant and turtlehead by Carole Ottesen; New York ironweed by David Cavagnaro.

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