While every region has its peculiarities, its special challenges, and its particular plants, the region I call Chicago-Minneapolis Axis tests and proves a gardener like no other.
To begin with, it makes him face up to the dismaying truth that means temperatures and average annual frost dates, beautiful things on paper, are useless meteorological abstractions.
It does no good to rely on a safe mean temperature for May when, this spring, the weather deviates from the mean, and we stiffer a killing frost on May 21.
Consider, for instance, the peach. A gardener along the Axis quickly discovers – no matter how nicely the isothermic lines wave across the map – that while peaches bear abundantly in Michigan, just across Lake Michigan in Wisconsin they stay alive only with difficulty.
For several years I have kept a record of the perennials that perform faithfully in our climate – plants that endure a temperature spread of 130° or more, sheet ice, sub-zero cold without snow cover, 80° degrees Fahrenheit days in early May, frost in late spring, high winds and driving rain – in short, plants as tough as we gardeners are.
All have sustained many winters without cover; all have demonstrated their ability to survive hot summers without artificial watering.
It goes without saying that bone-and-sinew plants top the list:
- Squills
- Crocus
- Tulips
- Bearded and Siberian iris
- Herbaceous peonies
- Hemerocallis
- Summer phlox
- Hardy asters
But there are others, and for those who would avoid the cost and trouble of repeated replacement, they make a handsome garden. Here are some of the best.
Most of the praise lavished on campanulas goes to canterbury hells. They are biennials, however, and troublesome.
Only once in 10 years have I been able to get really successful bloom from them.
When they do flower, a driving rain tears the blossoms to shreds. (The same is true of foxgloves). On the other hand, Campanula glomerata dahurica defies storms and supplies the deep, intense blue a late June garden needs. And it is iron-hardy.
Just as stormproof is Campanula persicifolia, the peachleaf bellflower, whose cool, icy blue flowers persist from peony time to summer’s end.
In July loosestrife, Lysimachitt clethroides, clusters starry white blossoms on spikes tapered and waved like little foxtails. Most handsome in a mass planting its flowers cut well to give style to midsummer arrangements.
A flower that seems to have been admired in Queen Victoria’s day, but virtually disappeared from the catalogs, is a sweet rocket, Hesperis matronalis.
Possessed of a wild urge to flower and increase, it comes in a sweetly scented rush of muted white or lavender when the summer phlox it loosely resembles is still in hard green bud.
Although a perennial, sweet rocket wants room for it most often acts as a self-seeding biennial and is very useful for naturalizing on roadsides, under maple trees, and other difficult places.
The respectable delphinium grower carefully stakes every stalk, but to me, this is bean-pole gardening and I don’t like it.
So while the gorgeous Pacific queens in our climate break and topple into the mud, only the most devilish storm throws down the Chinese and Blackmore Langdon strains.
These are also, in my experience, hardier and longer-lived than their California cousins.
Few perennials have all the virtues of the Pink variety of Lythrum superbum: hardiness, pleasing phlox-pink color, indifference to the vagaries of summer weather, and a remarkably long period of clean flowering—sometimes three full months.
Unfailingly generous with its rich blue or pink blossoms is the balloon flower, Platycodon grandiflorum, which flowers in July and August.
Although I seldom see them in other gardens I am very fond of three veteran filipendulas or meadowsweets. Formerly classed as spiraeas, they are still so listed in some catalogs.
All three erect fine terminal clusters of bloom.
- Filipendttla purpurea elegans displays clouds of tiny white flowers spiced with bright red stamens, and the effect is that of hazy pink.
- Filipendula ulmaria (Spiraea ulmaria), queen-of-the-meadow, flowers in a rich mass of white, although the color seems to be more like cream.
- Filipendula rulira (S. lobata), queen-of-the-prairie is the last to bloom, which my neighbors call Martha Washington plume. Its fluffy particles, officially peach-blossom pink, always remind me of a foaming strawberry soda.
The hostas still masquerade in some lists under their earlier name of funkia. They are the plantain lilies, useful and always dependable in the garden.
Hosta plantaginea, strongly fragrant, sends up cool, wax-white trumpets to scent late summer gardens.
Few perennials lend the border a more lastingly handsome dark green mass (with fragrant flowers that cut well) than dittany.
Dictamnus dims, This is sometimes known as gas-plant because in warm quiet weather the leaves exude a lemon-scented volatile oil which may ignite with a tiny puff of flame when touched with a lighted match.
Dittany dislikes transplanting but makes up for it by growing more beautiful each year.
Another desirable perennial not often seen today is the shrubby Clematis heracleaefolia davidiana. Neither weather nor pest has bothered it.
In late summer tight clusters of dark amethyst blue flowers with a scent to put perfume-makers to shame open along its stems.
There is a white-flowered bush clematis, too, Clematis recta mandschurica, with blossoms like those of the climbing Clematis paniculata.
Both are admittedly floppy but a peony hoop solves that problem.
Dependable performers under all conditions – some have been in my garden 20 years—are the following:
- sedums
- Thermopsis (good with delphiniums)
- coralbells
- celandine poppies (stylophorum)
- plume poppies (macleaya)
- baptisia, early-blooming monks-hood
- Boltonia
- Liatris
- Euphorbia epithymoides
- tall mallows
- veronicas
- columbine
- Oriental poppies (set 6 inches deeper than usual)
- The “dig-up” plants—gladiolus, dahlias, hymeno, callis – cause no trouble except the digging since they are wintered indoors.
On the other hand, only once in the last seven years have I had success with buddleias; winter does them in completely.
Chrysanthemums in the border are touch-and-go; even Minnesota varieties cannot be fully depended upon.
Hibiscus syriacus, rose of Sharon, has never stayed alive through more than two or three winters. The species roses, Harison’s, Hugo’s, and others, do very well. And so does the relatively new climber New Dawn, because it flowers on new wood.
Among the hardy bulbs are two that never fail. In full sun, 50 to 100 bulbs of the old tiger lily, L. tigrinum, produce a dazzling show.
Nothing except an occasional borer fazes them. Lycoris squamigera long known as Hall’s amaryllis, and called naked ladies by my friend the professor, is the only amaryllis we can winter in the open garden.
Each spring the bulbs (I once dug a bushel-basketful from one clump) put up their strap leaves. Later, after the leaves disappear tall flower stalks shoot up almost over tight.
Growing conditions and quirks of weather are never the same in any two gardens, and there will be gardeners along our Axis whose experiences differ from mine.
Nevertheless, from performances in my own garden and in others, I feel sure few plants not mentioned will stand the howling gales that blow down on us from the plains, the zero cold without covering snow, and the seesaw freezing and thawing.
Let me give due credit to just one more perennial, the Memorial-day peony, P. officinalis rubroplena. It is an ageless fixture in our old cemeteries. There are more flamboyant peonies.
Some of the popular palbiflora varieties, Japanese and Chinese “tree” types have bigger flowers and certainly are more costly. But this sturdy red, with its distinctive foliage, flowers first. Without fail it heralds the opening of the garden’s most brilliant season.
FGR-0453 by C Holway