We’ve had a couple of weeks where the temperatures didn’t go above freezing, so the leaves of many plants have died back. However, the leaves of some hardy perennials are still looking good, despite the frost and snow. Here are some photos of perennial foliage that can tough out some frost, and extend the gardening season in a northern garden.
The Asarum europaeum (European wild ginger) leaves are semi-evergreen, and keep about half of their leaves through the winter in my zone 3 garden. This little groundcover creates a great display in late fall and early spring, when other perennials have retreated.
Here are some new Asarum arifolium (hardy ginger) that were just planted a few weeks ago. These are rated for a warmer zone, so I’m not sure how they’ll handle the full winter temperatures, but they don’t seem to mind getting hit with freezing temperatures right after planting. The lovely shaped leaves are still green, and make a great sight. I’m impressed that they didn’t collapse, after the temperature dropped drastically, and the drying winds blew.
The Cornus canadensis (bunchberry) look good, and add some red fall colour too. This groundcover creates a green display under the evergreens, despite the temperatures.
Heuchera (coral bells) are another perennial that keep fresh looking leaves through the frost. Some Heuchera intensify their colour in the cool temperatures, giving lovely fall shades. This normally green and silver Heuchera ‘Mint Frost’ starts to get purple, red and orange colours as the weather turns cold. They keep these leaves until spring. The red stems make a good contrast on this showy perennial too.
The Heuchera ‘PlumPudding’ started with such an intense silvery purple, and has been keeping it through the frosts. The Astilbe next to them have collapsed, so these leaves get the attention.
The Campanula (bellflowers) maintain their green leaves through the cold too. They keep most of their leaves through the snow, and start the garden early in spring. They also keep some flowers long after others have disappeared. The glimpses of blue in a late fall/early winter garden are very uplifting. The Campanula poscharskyana (Serbian bellflower) above still has clusters of purple flowers. You can see I haven’t been deadheading since the frost. :)
Campanula portenschalgiana (dalmatian bellflower) has a few purple flowers, as well as the fully green leaves.
My Campanula carpatica (carpathian bellflower) also has a few purple bells above the fresh looking green leaves. They stand out when surrounded by the fallen deciduous leaves. My C. rotundifolia (harebell), C. cochlearifolia (fairy thimble bellflower) and other dwarf Campanula have a few blue flowers along with their well preserved leaves too. These dwarf bellflowers are showing green as soon as the snow melts in spring.
The Epimedium grandiflorum ‘Lilafee’ (lilac fairy barrenwort) has lots of green leaves, and they are just slightly twisted from the long frost.
Helleborus ‘Ivory Prince’ looks exactly the same as it did in early spring. This perennial has kept these leathery textured leaves in perfect shape for many months. They’re glossy, patterned, have a lovely form, and they have been since they appeared from under the spring snow. Yes, I have checked to make sure I didn’t plant plastic ones by mistake. They’re real and growing. This plant gets the award for best looking foliage regardless of the frost.
Dianthus caryophyllus (carnation) is another perennial that keeps great looking foliage from when the snow melts in spring to after the frost. The slender bluish gray leaves rise above the fallen tree leaves. Although I planted these purely for the pink flowers and wonderful scent in summer, I’ve enjoyed the foliage longer in fall and spring.
The Geranium ‘Rozanne’ have unmarred leaves and a few flowers still too. The patch of Johnson’s Blue geraniums next to them have shrivelled leaves, and no flowers, so these appear very fresh in comparison. The Johnson’s Blue got a head start in spring, but the Rozanne geranium has been the strong finisher, and much longer bloomer.
Dryopteris expansa (spiny wood fern) has the most evergreen fronds of all my ferns. The spiny wood fern usually keeps a few fronds under the snow, so it is easy to spot in spring. All of my other garden ferns have shrivelled, but these are still showing perfect pinna. The Onoclea sensibilis (sensitive fern) were the first ferns to collapse, even before the frost, when it was only 4° C (40° F).”It’s too chilly. I surrender,” they gasped as they disintegrated. It makes sense that lacy ferns with so much exposed surface area are the first to desiccate when the cold comes, so I wonder how the Dryopteris can maintain their appearance.
The Pulmonaria ‘Samourai’ leaves still have their silver colour, and intact foliage. These long silver leaves are especially showy against the piles of brown fall leaves.
When the temperatures didn’t rise above freezing for a couple of weeks, and combined with bitter winds, we got down to about -15° C (5° F) with the windchill. I’m always surprised that some hardy perennials manage to keep their leaves under these conditions. I’ve been adding more of these perennials to the garden, since they maintain a fresh appearance through the cold. In a short growing season, the garden can look bare when the frost hits, and temperatures don’t climb above freezing. Being able to see green leaves, or fall colour, instead of withered foliage, gives me an incentive to wander the garden in the crisper temperatures. These plants also give a quick start in spring, with an early shot of green for a northern garden.
Which plants in your garden keep their leaves the longest after you get extended freezing temperatures?