It’s time for snowdrops and hellebores, and fresh new shoots of other early bloomers poking out of the soil–so who wants to contemplate the end of the gardening season when the new one has hardly begun? The thing is, having interesting things to look at in fall requires some forethought. It can take a while to track down some of the gems of the autumn garden, because they’re often not readily available in garden centers during the usual spring shopping frenzy. And if you wait until fall to plant them, then you’ve missed out their other interesting features earlier on. But if you start hunting for them now, and get them into the ground in the next few months, they’ll have plenty of time to get settled in and make a good show for you as the growing season draws to a close.
I have so many fall favorites that it’s tough to whittle down the list, but I’ve done my best to select some that you may not have considered before. To give you a head start, I’ve supplied a couple of online sources for each, based on the results of a Google search. I don’t have any connection to or personal experience with any of these nurseries. (I suggest checking out any potential source on Garden Watchdog before ordering.)
Three Late, Late Bloomers
There’s no shortage of flowers for fall, and they’re all welcome for fresh color at a time when many plants are on the decline. The three I’ve chosen here are particularly late to open, usually peaking in mid- to late October here in southeastern PA.
Unlike our native asters, which have been reclassified into a number of other genera, Tatarian aster is still an Aster: specifically, Aster tataricus. The general consensus seems to be that the species reaches 6 to 8 feet tall, but listed heights for the “dwarf” selection ‘Jindai’ are anywhere from 3 to 6 feet. I suspect that most places sell the cultivar, even if they list it as the species. I’ve had what is supposedly ‘Jindai’ reach 7 feet tall in rich, moist soil and divisions from those same plants consistently reach 3 to 5 feet tall just a few hundred feet away, in drier conditions.
Even within one patch, the stem heights can vary widely. You’ll just have to try it for yourself and see how it performs in your particular conditions, but it’s fair to assume it’s a back-of-the-border plant pretty much anywhere it’s hardy (generally Zones 3 to 9).
You also need to be aware that it spreads to form broad patches, so it’s a not a good choice for a small garden or a tightly controlled formal border.
Where Tatarian aster really shines is in combinations with late-flowering or fall-colored deciduous shrubs and trees, or paired with tall, warm-season ornamental grasses, such as switch grasses (Panicum).
In this part of Pennsylvania, Tatarian aster usually starts flowering in the first or second week or October and continues until late October, or even well into November if we don’t get a hard freeze. I often see it loaded with bees and butterflies, as it’s usually one of the very last flowers in bloom.
Azure monkshood (Aconitum carmichaelii Arendsii Group) is another gem for tall, mid-fall flowers. Though it’s among the last perennials to bloom, it’s among the first to send up new leaves in spring.
The deeply lobed leaves start out tinged with red but quickly turn bright green as the spring progresses.
Finally, the hooded blooms open in late September to early October. They are usually a rich purple-blue, but the intensity can vary.
They are distinctive among the more common reds, oranges, yellows, pinks, browns, and blacks of the season.
Like Tatarian aster, azure monkshood is tall enough to show off well against fall-colored trees, shrubs, and grasses. It’s much less vigorous than that other late bloomer, though: never a thug.
There’s distinct variation in the height descriptions of plants sold as Aconitum carmichaelii ‘Arendsii’ or Arendsii Group: Some say 2 to 4 feet, some say 3 to 4 feet, and others claim 5 to 6 feet, which is about how tall mine get. You may have to try a few plant or seed sources or experiment with different planting sites if you want a particular height range. A couple of plant sources include Digging Dog Nursery and White Flower Farm; for seeds, try Plant World Seeds.
My third pick from the late bloomers is a short one: ‘Ozawa’ japanese onion (Allium thunbergii). At about 9 inches tall in flower, this one is small enough–and well-behaved enough–to fit into pretty much any garden.
It’s always a surprise to see the purplish pink flowers open in October, since the plant is easy to overlook during the growing season. In fact, its clumps of slender leaves look so much like weedy wild onion that you may want to leave its label nearby so you don’t pull it out accidentally. Which…um…explains why I don’t have this plant growing here right at the moment. I plan to reacquire it as soon as possible, though. A few sources that currently have it available include Klehm’s Song Sparrow, Lazy S’s Farm, and Quackin’ Grass Nursery.
Another ornamental feature of ‘Ozawa’ Japanese onion is the rich orange fall color of the foliage (just starting to develop in the shot below). Pink and orange together during the growing season can be a little jarring, but at this time of the season, any last bits of color are welcome.
Three for Seedheads or Berries
Oh, how to choose from among the many superb seedheads? Well, one that’s a particular favorite of mine comes from a perennial that’s also beautiful earlier in the growing season: tuberous-rooted Jerusalem sage (Phlomis tuberosa).
The common name isn’t elegant, but the plant is, with tall stems that carry whorls of lavender-pink flowers for a few weeks in early summer.
Once the flowers are finished, it can be tempting to trim off the spent stems, especially when they’re turning brown just as other colors are heating up in midsummer.
But if you can keep your clippers off them, I think you too would enjoy their striking form in your late-summer and autumn garden, with tall grasses, fall-colored foliage, late-flowering partners, and other striking seedheads.
You can find plants of tuberous-rooted Jerusalem sage at Bluestone Perennials and Digging Dog Nursery, among other places. (I started out with ‘Amazone’, but it has seeded very lightly, and I can’t tell any difference between them and the cultivar.)
If you’re not into appreciating seedheads, perhaps the beautyberries (Callicarpa) would be more to your liking. I’ve tried a few of these deciduous shrubs here and have the best luck with the species C. dichotoma. I cut it back to about 4 inches every spring, and it fills out to 3 to 4 feet tall and wide by fall: a nice size for a mixed border or foundation planting.
Clustered flowers appear along the current year’s growth in mid- to late summer. They’re pretty but not wow-inspiring.
The berries are the best ornamental feature: hence the name “beautyberry.” (And say, yes, you can eat some of these purple berries, at least of some species, according to Eat the Weeds. That article does say that C. dichotoma berries are too bitter to eat, but I’ve eaten them and am still alive.)
The fruits of ‘Early Amethyst’ usually color up in early fall, while ‘Issai’ is at its purplicious peak here in late September, October, and November.
There’s also a white-fruited version of C. dichotoma, sold as ‘Albifructus’ or C. dichotoma f. albifructa.
While the berries of C. dichotoma are still doing their thing, the leaves develop their yellow fall color, adding even more to the seasonal show.
Once the leaves drop, the berries are even more visible…
…and they can linger well into winter. That’s a lot of return from a relatively small shrub!
Another of my favorite multi-season shrubs is ‘Flying Dragon’ hardy orange (Poncirus trifoliata or Citrus trifoliata). The curiously contorted and wickedly thorny stems carry an abundance of white flowers in late spring.
As the flowers finish, ‘Flying Dragon’ becomes a study in green, with glossy leaves, green stems, and rounded fruits.
It begins to grab attention again in mid- to late September, when the fruits ripen through yellowish green to rich yellow.
The fruits are edible but not tasty–they’re mostly seeds, anyway–so there’s no need to plan for access for harvesting. It’s best to keep ‘Flying Dragon’ toward the middle or back of a bed or border, where it can mingle with other late-season beauties without snagging passersby.
As the season winds down, the leaves also develop yellow fall color.
The fruits usually drop as fall draws to a close but sometimes the linger into early winter, providing extra interest to the green winter stems.
Shrubs and trees for autumn color changes? Sure, there a lots of them. Herbaceous perennials? Yep, some terrific fall foliage there as well. Annuals for lovely late-season leaves? Not too many. There are ornamental cabbages and kales, of course, usually sold in pots for use as fall fillers in borders and pots, but they often look like afterthoughts. ‘Redbor’ kale (Brassica oleracea Acephala Group) is a variety normally sold as an edible, but it’s beautiful enough to earn a place in beds and mixed borders through the growing season.
The young plants have purple stems, with green leaves that usually are tinged with purple (more green if the weather is hot, more purple if it’s on the cooler side).
As the season progresses and temperatures are consistently cooler, the purple becomes more intense.
The strongly upright stems can easily reach 2 to 3 feet by the end of the season–even taller in rich soil. Even a single plant can be an interesting accent; a grouping can be quite striking.
Like many other outstanding fall plants, ‘Redbor’ kale can also look good into winter.
Technically a biennial, it occasionally overwinters for me and flowers the second year. Usually, though, either the wet causes it to rot, or the wild bunnies get it first.
For perennial fall color–and earlier interest too–consider the Bowman’s roots (Porteranthus or Gillenia). Native mainly to the eastern half of the U.S., this under-appreciated genus probably won’t ever grace a catalog cover, as it’s not an in-your-face sort of beauty. It’s not simply a “filler” plant, though. The dainty white flowers bloom in early summer: charming in some shade and even more abundant in sunnier sites. The effect is something like that of baby’s breath (Gypsophila paniculata)–nice for those of us with acid soil, where baby’s breath can be a bit sulky.
During the summer, it’s just green, but the leaves are pleasing for their fine texture. I particularly like the lacy look of American ipecac (Porteranthus stipulatus). As fall approaches, the developing fall color of its leaves and small seedheads catches the eye again. The foliage can range from maroon to rich shades of red and orange.
And last, a selection of another native: ‘Tor’ birchleaf spirea (Spiraea betulifolia). (Well, I say “native”…depending on which source you believe, the species is native to eastern Asia, or the Pacific Northwest, or various other areas in the U.S. and Canada.) Whatever its origin, it’s cute in bloom, forming a dense mound practically smothered with clusters of white flowers.
As with the Bowman’s roots, it’s easy to overlook ‘Tor’ birchleaf spirea in summer; it’s just a dense mound of foliage typically 2 to 3 feet tall and wide. But oh, wait until autumn, when the grayish green leaves take on vibrant yellows, oranges, golds, reds, and purples. Each year, the colors are a bit different, but the effect is always spectacular.
Well, that’s enough to be going on for this fall, I think! I hope you found a few things of interest on the list. One more thing: today (March 1, 2016) is the last day for the giveaway to win a copy of The Perennial Matchmaker at Goodreads. Good luck to all of you who have entered!