5 Super-Hardy Perennials

These hardy perennials can take even the toughest winter.

By Graham Rice

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For gardeners in the colder zones, the choice of plants is limited to those that will reliably survive the most ferocious winters. Snow cover helps, providing an insulating blanket over the plants, but all too often the icy weather comes first and snow comes later. Good drainage can also help, because often it’s persistently soggy soil as much as cold that does the damage.

But there are some lovely perennials that really are super-hardy; these five tough customers are hardy as far north as USDA Plant Hardiness Zone 3 (–40°F).

‘Arendsii’ Monkshood

Aconitum carmichaelii ‘Arendsii’
Invaluable for bringing rich lavender-blue coloring to the normally orange and rusty shades of the fall garden, ‘Arendsii’ has leathery dark green leaves that set off the short spikes of flowers beautifully. The tuberous roots are easily divided, but all parts of the plant are poisonous, so take the precaution of wearing gloves. Best in sun.
Height: 4 feet; hardy to Zone 3

‘Arendsii’ Monkshood
‘Jack Frost’ Siberian Bugloss

‘Jack Frost’ Siberian Bugloss

Brunnera macrophylla ‘Jack Frost’
‘Jack Frost’ is one of the most impressive new perennials of recent years. The heart-shaped, shimmering silvered leaves with their neat green veins are topped in spring with dancing forget-me-not-blue flowers. Happy in shade in any reasonable soil, and tolerant of dry shade once established, it also smothers weeds and makes a fine container specimen.
18 inches; Zone 3

‘Ruby Giant’ Coneflower

Echinacea purpurea ‘Ruby Giant’
For sheer drama, it’s tough to beat one of the large-flowered coneflowers. ‘Ruby Giant’ has flowers 4 inches across that open reddish pink and mature to silvery pink—each with that rounded red-and-honey central cone. The stems on this butterfly magnet branch well so that each plant features an impressive display.
3 feet; Zone 3

‘Ruby Giant’ Coneflower
Bleeding Heart

Bleeding Heart

Dicentra spectabilis
The bleeding heart is an intriguing perennial, with the arching growth of its succulent stems and pendant pink-and-white flowers. It may be damaged by late frosts but always recovers. Look out too for the lovely pure white form. Sometimes listed under its new name, Lamprocapnos spectabilis.
3 feet; Zone 3

‘Autumn Joy’ Stonecrop

Sedum ‘Autumn Joy’
It seems unlikely that a plant with such succulent foliage could be so frost-hardy, but it’s not for nothing that sedums of this type are sometimes called ice plants. Broad, deep pink, slightly domed flower heads open in late summer and fall and turn russet brown as they remain on the plant for late fall and winter interest.
20 inches; Zone 3

Autumn Joy Stonecrop

Photos: © Gardenphotos.com

Graham Rice @ Organic Gardening

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