Northern Shade Gardening

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.

Asarum europaeum leaves October

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.

Asarum arifolium leaves October

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.

Cornus canadensis leaves October

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 'Mint Frost' leaves October

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.

Heuchera 'Plum Pudding' leaves October

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.

Campanula poscharskyana leaves October

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 porscharskyana (Serbian bellflower) above still has clusters of purple flowers. You can see I haven’t been deadheading since the frost. :)

Campanula portenschlagiana leaves October

Campanula portenschalgiana (dalmatian bellflower) has a few purple flowers, as well as the fully green leaves.

Campanula carpatica leaves October

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.

Epimedium grandiflorum 'Lilafee' leaves October

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' leaves October

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 leaves October

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.

Geranium 'Rozanne' leaves October

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 fronds October

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’s 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.

Pulmonaria 'samourai' (lungwort) leaves October

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?

I’ve been expanding the shady bed that I created under the conifer trees in the front yard. Some of the branches are low, so I’ve added some  shorter groundcover plants where there isn’t as much room. The newest woodland additions are Asarum arifolium (wild ginger), Hepatica nobilis (liverleaf) and Brunnera macropylla ‘Looking Glass’ (siberian bugloss).

front shade bed under conifers

I love the texture of the natural mulch that has accumulated under the conifers. There is a layer of decomposing tree debris that is as thick as my trowel blade. It’s very easy to plant in. I can make the planting holes with my bare hands, since it’s so soft.  I think the new plants will love this location.

Asarum arifolium new shipped plants

Here are the Asarum arifolium plants that I ordered. They looked very healthy as I unpacked them. The rootballs were nice and moist. The leaves are in good shape for having been through the mail.

Asarum arifolium (wild ginger) under spruce

These Asarum arifolium are  good looking wild gingers. However, I’m not sure if they will be fully hardy in zone 3. My Asarum europaeum have overwintered fine, so I went with ten of these groundcover plants. If they do well, I’ll expand the group next spring. They should fill in, and cover the ground with their wonderful leaves eventually.

Asarum arifolium (wild ginger) leaf closeup

Aren’t the leaves a great shape? They are halfway between an arrow and a heart shape. In the above photo two above, you can see the variety of leaf shapes, from arrow on the right, to heart on the left. Some of the leaves have faint markings. The markings should get more silvery as the plants grow, so I think they will fit in well with the silver colours running through this bed.

Asarum arifolium (wild ginger) group under spruce

The roots of these Asarum had a very strong ginger smell as I unpacked and planted them. I think they’ll thrive in all the natural mulch that has accumulated here, and the conditions under the trees. By spring I’ll see if they tolerate  the Edmonton winter temperatures.

Brunnera macrophylla 'Jack Frost' (Siberian bugloss) under pine

Here is a group of  Brunnera macrophylla ‘Jack Frost’ at the front of the bed. The leaves are holding up well to the mild frosts.  I’ve added a group of Brunnera macrophylla ‘Looking Glass’, which will have the most silver colour of all the perennials here, since they develop a strong overall silver colour in summer. The newly added Looking Glass is just around the pine, but their leaves don’t look as good as these yet.

Hepatica nobilis (liverleaf) dormant

This is  a group of Hepatica nobilis‘, which will have blue flowers in spring. They arrived dormant, so most of the interesting parts are underground right now. You can just see the green tips of two of the plants from the group of five. They should enjoy the shady location, with lots of humus, from decomposing tree debris. I got the idea for adding these from Dave at The Home Bug Garden.

Aruncus aethusifolius (dwarf goatsbeard) under pine

Here are some of the Aruncus aethusifolius plants. that are planted on the west edge. There is a group of seven plants that go around the pine trunks to the left here. They will have creamy flowers next summer.

Epimedium 'Lilafee' under spruce

These Epimedium grandiflorum ‘Lilafee’ (lilac fairy barrenwort) that were planted earlier are thriving in this location, and expanding to cover their area. The light green leaves with the asymmetrical heart shapes show up well. In late spring they will have purple flowers with long spurs, held up above the leaves.

Hosta 'Ginko Craig' under spruce

The two little Hosta ‘Ginko Craig’ are doing well so far. They are supposed to be good spreaders, so they should fill their section under the tree. The narrow margin of white on the leaves gives a little glimmer in the darker area under the trees.

Cornus canadensis (bunchberry) plant under spruce

There is a group of about 15 Cornus canadensis (bunchberry) now. I’ve been adding to this group as I found more in local greenhouses. They already look as if they are a natural part of the woodland floor, and you’d hardly know they have been recently planted. I’ve seen large patches of these spreading out under conifers in the mountains, so they will enjoy this shady site.

Cornus canadensis (bunchberry) under spruce 2

This natural groundcover should fill in well. I might end up adding some twinflower with them, as I’ve seen that combination in the forest, and it’s an attractive woodland look.

front bed under conifers older plants

I’ve been gradually expanding this woodland bed all summer, weaving between the conifers. I’m going for a look midway between a garden and a forest floor in this shady bed. These will probably be the last plants added for this year, since we are getting much cooler temperatures now. I have some ideas for more additions, and will probably start again in spring. I’d like to add some Polygonatum odoratum ‘Variegatum’, and some Pulmonaria. I’ve been very pleased with how healthy all the plants have been so far. They seem to be doing very well under the conifers. In spring, I’ll see how they overwintered here, and will expand this bed out to the north, to the next spruce tree. Here is an earlier post, about when this shade garden was first planted. This post shows some of the additional shade plantings.

Did you mange to finish all of your fall planting yet?

Heuchera ‘Plum Pudding’ (coral bells), with its shiny purple leaves, can really catch your eye in a shady border. Here is a garden bed that I’ve rearranged, including some perennials with purple foliage. This garden area is in shade, so the perennials have to thrive with just an hour or two of sunlight.

Heuchera 'Plum Pudding' foliage

The most eye catching purple foliage is from the Heuchera ‘Plum Pudding’. I particularly like this shade of purple as it has a metallic silver tinge to it. You can see in the above photo how the silvery overlay reflects the light in this darker area. Dark colours can fade into the background in the shade, but the silver highlights brighten up the foliage. The leaves are very vivid, and I like the way they add a little drama  here.

One of the advantages of Heuchera is that their leaves stay fresh looking through the mild frosts. In fact, the frost often brings out the colors in Heuchera. In the short growing season of zone 3, it really extends the gardening season when plants can look good into October and November. Heuchera keep many of their leaves under the snow, so they also look great in early spring, before other  perennials have risen. Here is some information about Heuchera ‘Mint Frost’, which has silvery green leaves.

The foliage of the Heuchera make a great ground cover, since they produce many overlapping broad leaves. Smaller plants can’t grow through, so there is less weeding. However, the 2 m (6 ft) tall Actaea has no trouble growing over the 25 cm (10 in) tall Heuchera, so they make a good combination. The group of three Heuchera make a nice clump in front of the Actaea.

Actaea racemosa 'Atropurpurea' leaves

The tall perennnial behind is Actaea racemosa ‘Atropurpurea’ (Cimicifuga, bugbane). This plant has purple tinges to the edges of its leaves, and reddish purple stems. It grows a couple of metres tall (around 6ft). The leaves will make a good backdrop to the other plants. My other Actaea racemosa have tall white flower wands, above my head. These plants will flowers with a minimal amount of light.

Heuchera 'Plum Pudding' and Astilbe

The purple Heuchera is planted next to some Astilbe simplicifolia ‘Hennies Graafland’. I dug up and divided the Astilbe, which had too many lily of the valley closing in on them. Now these short astilbe are towards the front of the bed, where they can be seen better, and have more space. I like the shiny Astilbe leaves next to the glossy metallic purple leaves of the Heuchera. The glossy leaves of A. simplicifolia are highly reflective in the shade. They still have their faded flower plumes on them, with fall colours now. I think the bright pink flowers of summer will look good with the dark purple leaves, but I’ll see when they flower fresh next year.

This section of the border is going to have mostly purple highlights on the leaves. I saw a nice Tiarella that had dark purple centres on its leaves that I might add too. To the south of this section, the plants have more silver highlights. The Heuchera ‘Plum Pudding’, with both purple and silver colours, will make a nice transition between them. I love fall gardening, redesigning the beds, transplanting, dividing the perennials, and adding new plants. Then you wait over the winter, picturing it in your mind. I’m eager to see how this garden border will look next year, as the plants grow in.