Northern Shade Gardening

Geranium

A shimmery blue flower and an extended blooming time are two great traits for a perennial. The long flowering Geranium ‘Johnson’s Blue’ (cranesbill) is an attractive perennial for planting under shrubs or in a border. Mine are planted under a lilac tree, where they provide bright blue colour long after the lilac has stopped blooming.

Johnson’s Blue has  been flowering for a couple of months without stop. These plants are in part-shade, yet they have been covered in flowers. There are many fresh buds still ready to open and reveal their glimmering flowers. They look striking when the sun is shining on the blooms.

The flowers are a purplish blue, with faint purple lines giving an iridescent look to the petals. You can see from this closeup how much depth of colour the blooms have. A small white centre sets off the blue color. The simple open rounded petals are very appealing.

These Johnson’s Blue geraniums are about 60 cm (2 ft) tall and wide. The deeply lobed leaves are attractive before the plant starts to bloom. The stems have  a loose habit, with their flowers weaving into the edges of the plants which surround them. This can look fine, depending on the neighbouring plants. If you don’t want them mixing with other flowers, they look good as a grouping around shrubs with an open base, or under a tree that doesn’t cast too much shade. They need to be sited where their loose structure looks appropriate.

Geranium

Geraniums are relatively low maintenance plants. All they need is to be cut back in late fall or early spring, and to be deadheaded as their flowers fade. The dead blooms are easy to spot. The long, thin developing seed sticks out of the old bloom, giving them the common name, cranesbill. I try to cut off the finished blooms before the bill gets too long. This is one plant I prefer to deadhead with snips, rather than my fingernails, since they are sticky.

Geranium

I’ve thought about trying ‘Rozanne’ and ‘Jolly Bee’ geraniums, but I’m not sure if they’ll be as hardy in zone 3. I might try planting one of each, to see if they return next spring, and compare their hardiness to Johnson’s Blue.

Perennial geraniums are another mainstay in the garden.  They have attractive, long blooming flowers, and tolerate part-shade. Removing the faded blooms, and cutting back the foliage for winter are the only maintenance required.

What are your favourite perennial geraniums, and how do you place them?

Here is a followup comparison of Johnson’s Blue and Rozanne geraniums in my garden.

Phlox paniculata

Bright, clean white is an elegant flower colour for the late summer garden. The 3 brightest whites in my garden right now are Phlox paniculata ‘David’ (garden phlox), Hydrangea paniculata ‘Grandiflora’ (PG Hydrangea),  and Impatiens walleriana ‘Fiesta White’ (double impatiens). White flowers look cool and refreshing, like a crisp, white cotton shirt.

Phlox paniculata is a stately perennial for the summer and fall garden. It can form good sized clumps, that stand out in a flower bed. Mine are 1m to 1.3m tall (3ft to 4ft). Despite their height, they don’t need staking, although a fierce storm can test their sturdiness. The large beautiful blooms are  long lasting. I cut the flowers as they fade, to keep the plant blooming. They are a classic for the summer garden, and combine well with just about any other perennial around them.

This one is flowering in part-shade. Its partner across the yard is in medium shade and has not started blooming yet. They flower better without too much shade, but tolerate part-shade well.

Hydrangea paniculata

I used to have different varieties of P. paniculata in a previous garden, and was fortunate not to have much powdery mildew. However if it’s a problem, the variety ‘David’ is especially known for its resistance to powdery mildew.

Hydrangea paniculata ‘Grandiflora’ (PG hydrangea) is another prominent bloomer this month. I compared it to  some other hydrangea in another post. The last time I posted about it, the flowers were only partially out. This photo shows how the white panicles are more striking now that they’ve had time to open. It’s an outstanding shrub for part-shade. This PG is on the north side of a fence.  I’m very pleased with the number of blooms this shrub has, for being in a mostly shady site.  A smaller PG hydrangea, located in deeper shade under a willow tree, is not producing blooms the same way.

Like the Phlox, the large hydrangea blooms are long-lasting. It’s always satisfying when a gorgeous flower blooms for an extended time. In the late fall, the panicles still add interest as they fade to brown. Early next spring I’ll snip off the old flowers.

Here’s a much smaller white bloom. This double flowering impatiens is ‘Fiesta White’. Up close, they sometimes have the faintest, pale pink tinge. These small plants are covered in the pretty blossoms. The flowers give the appearance of miniature rose blooms with a multitude of petals. Impatiens don’t need deadheading to keep them flowering. The old blooms fall off, and a steady supply of new buds replace them.

They are satisfied growing in medium shade, where the soil stays moister. Deep shade cuts into the bloom count.

Impatiens are like an annual in zone 3. They can only be placed outside after the last frosts, and will finish quickly after the first frosts in September or October, but until then they’ll brighten the shade. Yesterday there was a full moon. As I looked out the window late at night, these flowers were visible, twinkling in the moonlight.

Impatiens walleriana

Here is apost I wrote before, about some white flowering plants in the spring.

Do you grow any stalwarts like hydrangea or phlox, that you can depend on to put on a good display?

Here are some combinations of foliage and flowers in the summer shade garden. Silver leaves weave through many of the pictures. The silver looks good in the shade, brightening the shadows and catching the eye. The fine texture of the ferns looks interesting when combined with more solid, round or elongated leaves. Adding a variety of textures, shapes, and patterns makes the plantings look more appealing, with or without flowers.

The heart shaped leaves in the first photo are Brunnera macrophylla ‘Mr. Morse’ (Mr. Morse Siberian bugloss). The foliage of this perennial is almost identical  to B. macrophylla ‘Jack Frost’, but the flowers are white instead of sky blue. Like other Brunnera, it is thriving in the shadows. It laughs at the maple tree that steals all the sunshine and tries to bombard it with keys. The Brunnera have been very successful at suppressing the maple seedling growth, making them great understory plants. Mr. Morse adds beautiful white flowers early in the year, but the foliage is a winner for the whole season.

The fern behind the Brunnera is Athyrium filix-femina ‘Lady In Red’ (lady in red fern). It’s a lush looking fern with fresh green fronds that have red midribs. It puts out new fronds throughout the summer, so it’s still looking good in August. In fact, it’s looking much better than when I planted it in the spring. When I first got it in May, I put the round pot down in my backyard. Some very strong wind gusts blew it over and rolled it all along the the back path. Many of the fronds broke and eventually turned crispy brown. You would never know it now, since it has filled in so well.

The second photo shows another A. filix-femina ‘Lady In Red’, with all of the new fronds that have unrolled. The red midribs are most noticeable at the bottom and fade at the tips where the fronds narrow to a point. I like the lighter green next to other dark green foliage.

On the left is a clump of Asarum europaeum, with dark, round, glossy leaves. This great, low growing perennial looks like its leaves have been individually polished. I love the look of the ginger’s solid leaves contrasting with the finely cut foliage of the fern. Earlier in the year it had small brown flowers hidden under the leaves. This ground cover is definitely grown for its appealing foliage, rather than the inconspicuous flowers.

Behind the fern are the long silver leaves of Pulmonaria x ‘Samourai’ (Samourai lungwort). This perennial’s leaves have a matte surface. Although it had pretty blue flowers earlier in the year, it looks just as good without any flowers on it. I like the combination of fern, ginger and lungwort together in the shade.

This photo shows three P. x ‘Samourai’, with part of a clump of Asarum europaeum (European wild ginger) in the shadow on the lower right. If you click to enlarge, you can see the little ginger better. There are ten Asarum planted altogether in this area. I’ll see how it fills in next year. These plants get an hour or so of direct light in the early evening, and a bit of dappled light now and then. They thrive in this shady location, and the leaves always look good.

Here’s Heuchera ‘Mint Frost’ on a rainy day. The leaves are glistening with puddles of rain on them, and more drops landing. The mature leaves are a light silvery mint green with medium green veins. The newer leaves are a lighter, minty green with the same veining. You can click to enlarge, to see the red petioles holding out the dimpled leaves. If you are looking for a heuchera with a bit of pattern to the leaves, but not in the orange and red tones, this is a good choice. This is new to my garden this year, so I’ll be able to tell more about this cultivar’s hardiness next spring. On the upper right is another group of Pulmonaria x ‘Samourai’. The two look good together in this location that gets part shade.

This grouping of three Brunnera macrophylla ‘Jack Frost’ (Jack Frost Siberian bugloss) is in front of Athyrium x ‘Ghost’ (ghost fern). The Jack Frost clump is about 1 metre (3 feet) across. The silver patterned hearts show why  it’s one of my favourite perennials. The Athyrium x ‘Ghost’ fern behind echoes a similar silver colour, but with fine textured foliage. The shape and size of the fronds show look like one of its parents, Athyrium filix-femina (lady fern). The silver colour is a clue to its other parent, Athyrium niponicum (Japanese painted fern). Both of the ghost ferns are about 60 cm (2 feet) tall now. The silver foliage of the Jack Frost and the ghost fern combination looks good surrounded by darker leaves. To the right is a group of Campanula carpatica (Carpathian bellflower). These plants have been moved around this same area 3 times in 3 years. They’ve been very good sports about it, but they should fill in a little more, if I leave them alone for a while.

Here’s a closeup of a ghost fern frond with Campanula rotundifolia (harebells). The slender flower stalks of the harebell lean against other plants in the shade. I like the look of the little bluish purple bells here and there, weaving delicately through the garden floor.

You can see by the maple keys on the ground, that the maple tree and I have a disagreement about what makes a garden.  Acer believes in a maple monoculture, and drops thousands of keys every year to turn this into a maple paradise. So far in our game of garden domination, the score is maple: 1 tree standing vs gardener: 10 000 keys defeated.

It’s not all foliage in the shade garden. This is Astilbe simplicifolia ‘Hennie Graafland’. The leaves are glossy, and the feathery plumes are pink. I wrote about some other astilbe that I grow in a previous post.  The foliage of Aruncus dioicus (goatsbeard) is in the background. Being 2 metres (6 feet) tall, the leaves of the Aruncus make a pleasing green backdrop to show off the flowers of other perennials.

I like to add interest by combining glossy leaves with matte leaves, round shapes with elongated ones, feathery textures with dense surfaces, and patterned leaves next to solid coloured leaves. You can see some other shade perennial combinations in this fall post.

Do you have any plant combinations for the shade that you particularly like?