Winter-hardy Perennials: 6 Cold-resistant Beauties

Only the toughest get into the garden. And in this case: only the hardiest. We have selected some special gems for you among the absolutely hardy perennials from winter hardiness zones 1 and 2. In this article you will also learn everything you need to know about the classification of the zones and to what extent you can include them in your perennial planning.

Hardy Perennials: Winter Hardiness Zones Explained

Maps showing the various winter hardiness zones of the earth provide information on how cold it can get on average in a particular region. Accordingly, many perennial nurseries have now divided their range of perennials into winter hardiness zones (usually 11 zones). Each zone is assigned a temperature range that indicates the lowest temperatures possible for a region. In Europe, zones 6 (-23.4 to -17.8°C), 7 (-17.8 to -12.3°C) and 8 (-12.3 to -6.7°C) are represented. This means that in principle all plants that are assigned to winter hardiness zone 8 or below are considered hardy in Europe.

Winter hardiness zones as a guide

Geographical location is not the only decisive factor for air and soil temperature. Many other factors have an influence. Even in your own garden there can be differences – open areas, for example, are more susceptible to frost than sheltered spots near the house.

And last but not least, you can of course also significantly improve the survival chances of your perennials with winter protection measures.

The winter hardiness zones are therefore of great importance, but in the end they only provide a rough guide for planning your perennials. Our six hardy perennials are so tough that you will definitely not have to worry about them next winter.

1. rosebay: a mountain perennial with a strong character

Botanical name: Rhadiola rosea

Winter hardiness zone: Z1

Habitat: Sunny

The natural range of the rosebay is known as the Holarctic. This area includes most of the northern hemisphere. As a plant that has even penetrated into arctic regions, the rose arum has earned its status as a hardy perennial.

The mountain plant owes its name to the smell of its rhizome. When you cut it, a delicate scent of roses soon fills the air. Its grey-green, unbranched shoots appear almost succulent. Pointed leaves and yellow, rounded inflorescences give the rosebay a robust yet attractive appearance.

The mountain plant is suitable for sunny, not too nutrient-rich and not too dry locations. It also needs stony to rocky soil – preferably nutrient-rich and with a slightly acidic pH value.

2. Greenland daisy: Robust northern light with pretty flowers

Botanical name: Arctanthemum arcticum

Winter hardiness zone: Z1

Position: sunny

The Greenland daisy also comes from the Arctic zone. Cold and frost cannot harm this northern beauty. However, it does have one weakness: it often withers away in prolonged waterlogging. So a well-drained soil is a must, preferably with sandy components – but still humus-rich and nutrient-rich.

In addition to its extreme winter hardiness, its late and abundant flowering is also one of its strengths. Between September and October, Arctanthemum arcticum stretches its radiant flower heads towards the sun. Together with numerous buzzing visitors, it thus prolongs every summer. The hardy perennial is suitable for a wide variety of planting compositions, for example in herbaceous borders and colourful meadows.

3. ladder of heaven: winter-hardy perennials with noble flowers

Botanical name: Polemonium caeruleum

Winter hardiness zone: Z2

Habitat: sunny to semi-shady

The blue-flowered ladder of heaven is native to Siberia, parts of Europe, the Caucasus and Asia. It is also native to Europe, which is why it is particularly suitable for near-natural plantings, for example in cottage gardens. Its natural habitat is riparian forests, fresh meadows or corridors, but also streams and river courses. In the garden it feels at home near a pond or under woody plants.

The erect inflorescences stretch proudly upwards and usually appear from June to July. They are often surrounded by numerous insects and bring life to the summer garden.

4. three-flowered carnation: indestructible in all weather conditions

Botanical name: Geum triflorum

Hardiness zone: Z1

Habitat: sunny to off-sun

Species of carnation root are widespread. There are specimens in Europe as well as in South Africa, and also in North and South America. The native range of Geum triflorum is the western USA and central and western Canada. The Canadian provinces of British Columbia and Alberta have a continental climate, which is why the three-flowered carnationwort usually has to withstand harsh winters there.

The reddish bell-shaped flowers that adorn the carnationwort between May and August are quite delightful. They eventually give rise to characteristic seed heads that resemble little hairballs.

Stony and well-drained soils also provide ideal growing conditions for these small perennials. The three-flowered carnationwort not only defies freezing cold, but also survives dry and hot summers unscathed. It can be used as a ground cover, for example, or integrated into varied rock garden plantings.

5. common yarrow: winter-hardy perennial for near-natural plantings

Botanical name: Achillea millefolium

Winter hardiness zone: Z2

Habitat: sunny

The common yarrow is also called meadow yarrow. It is a wild perennial that is also native to Europe and a traditional medicinal plant. The species was originally found in Europe, Asia and America, but today it is found almost all over the world.

The finely feathered foliage and long stems are discreet and can therefore be perfectly integrated into wild-looking flower meadows. Bees and other insects also benefit from the yarrow’s long flowering period. The floating, white sea of flowers first appears in June and can sometimes last until September.

The common yarrow prefers a lean and stony/sandy garden soil. It should also be well-drained to prevent waterlogging.

6. worm fern: Perfect for lush shade beds

Botanical name: Dryopteris filix-mas

Winter hardiness zone: Z2

Position: semi-shady to shady

The worm fern is found on almost all continents of the world. It is a typical forest perennial and therefore often grows in the deep undergrowth or light shade of trees. But the species has also climbed the odd mountain.

It is not only a particularly hardy perennial, but also one of the most adaptable and tolerant ferns. It then unfurls its lush green fronds, which grow up to 130 centimetres high, from small, rolled-up leaflets. This stately appearance is a great addition to shade beds with fresh garden soil.