Northern Shade Gardening

Hydrangea and birdbath fall leaves

Hydrangea shrubs have enough room underneath, that you can make a beautiful layered garden by underplanting them with shorter plants. In summer I have some dwarf Campanula (bellflowers) producing purplish blue star shaped flowers in a low carpet under this Hydrangea paniculata. I love the look, and wanted to extend it to spring, so I’ve planted some Chionodoxa forbesii (glory of the snow) bulbs underneath. These early spring bulbs should flower before the bellflowers bloom, with their own version of starry flowers.

Campanula porscharskyana (bellflower) in flower

Above is  a photo of  Campanula poscharskyana (Serbian bellflower) from this summer. They start flowering midway through June, and continue intermittently all summer, and into fall. They look especially pretty under the Hydrangea, even before it flowers,  twinkling up through the branches. They are a gorgeous shade of purplish blue, with five narrow petals and white towards the centre. These bellflowers grows quite low to the ground, so they don’t interfere with the Hydrangea branches, and they fill the bare area underneath with beauty. Then in August and September, when the Hydrangea blooms in white, the little blue flowers of the Campanula look lovely paired with the large panicles. However, there are no flowers underneath the shrub before mid June, just the bellflower foliage.

Chionodoxa luciliae (glory of the snow) flowers spring

I  added some glory of the snow bulbs to bring some early blooms to this area. The blue stars are reminiscent of the Campanula and should have a similar effect. These have six petals, a dark line down each petal, and a white centre. The Chionodoxa luciliae start flowering during May in my zone 3 garden, so the Chionodoxa forbesii should start the colour show early too, before the bellflowers. These two Chionodoxa species seem interchangeable now. The pretty blue bulbs will bring some spring cheer, while the Hydrangea stems are still leafless. Then when the glory of the snow flowers fade, the bellflower groundcover should easily hide the slender bulb foliage as it dies back for the season. Usually the  Chionodoxa foliage disappears quickly.

planting Chionodoxa forbesii (glory of the snow)bulbs

Here is one of the bulb planting holes, in between the Campanula poscharskyana plants. I dug narrow holes among the perennials, to minimize the root damage. Then I planted 5 to 10 bulbs in each hole. Altogether I planted 50 Chionodoxa forbesii, but I could have planted more. These bulbs cover the  ground under the front half of the Hydrangea, and a bit around the sides. I could plant another 50 to really carpet the ground under the PG Hydrangea.

fall leaves under Hydrangea

The fall leaves were already covering the garden bed, as I watered in the newly planted bulbs. This will be some of my last outdoor gardening fun for the year, since the temperatures are so cool now. It is probably a little late to be planting bulbs in zone 3, but the weather warmed above freezing this week, the bulbs were on sale, and the picture of more blue flowers was running through my mind. Soon, a white quilt will be spread over top of the brown and green patchwork one. However, come spring, the flower parade will start as soon as the snow melts, and the early spring bulbs bloom.

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 poscharskyana (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. Here is another update from 2010 of the shady garden plants under the evergreens.