Canna lilies

Canna 'Tropicana' foliage

Cannas (members of the Cannaceae family) are not actually lilies, but for some reason unknown to me, that's what people call them. I just call them beautiful. Their big, colorful leaves remind me of banana trees and their exotic flowers make me think of the tropics.

Even if Cannas never flowered, their variegated foliage would make them worth growing. Look for the green-yellow variegation of 'Pretoria', as you see above, or the red-yellow-pink-green leaves of 'Tropicana' at top. Others like 'Red King Humbert' and 'Wyoming' have mahogany leaves.

Dwarf varieties get 18" to 3 feet tall. Standard varieties reach 4 - 6 feet tall.

Canna flowers may be yellow, orange or red.

In Seattle, cannas are most often grown as annuals. They will over-winter in mild years, but the past few have been too cold for many to survive. Cannas do well in containers and as focal points in mixed borders. When they are blooming, they're a sure sign of summer in Seattle.

More Smoke Trees

One of the most popular posts on this blog has been the article on purple smoke trees (Cotinus coggygria, vars. 'Purple Robe,' 'Royal Purple,' and others). These trees are in bloom, covered in puffs of "smoke," right now all over Seattle. But did you know that smoke trees come in colors other than purple?

I recently had the good fortune of discovering a golden version of the smoke tree growing next to a purple one. I do not know the specific name of this cultivar, but 'Golden Spirit' (C. coggygria 'Ancot') is one seen often in the trade.

Here is a close-up of its stunning gold foliage, with a few small puffs of smoky bloom beginning to show. The chartreuse leaves have dark green veination, adding to the visual interest. This is a good plant to keep in mind when you are wanting to use foliage color as a design element.

This is a green form of Cotinus, possibly a variety called 'Pink Champagne.' The pink puffs are interesting, though this plant is certainly not as dramatic as the purple or gold versions.



All Cotinus varieties are drought tolerant and do best in poor, even rocky, soils. They are noted for their fall color, brilliant yellows through red-orange.

Himalayan Honeysuckle

Himalayan honeysuckles (Leycesteria formosa) are in bloom right now in Seattle. You can't miss them, with these stunning flowers.

The actual flowers are these little white bells that you see above. The showy purple bracts that surround them are what catch your eye. These flowers will give way to berries (you can see a little red berry starting to form in the photo above) that are popular with birds. The berries start out green, turn red and then finally, black.

Himalayan honeysuckles are shrubs not vines, as are typical honeysuckles (Lonicera sp.) They grow quickly to fill a space 6' x 6'. In particularly cold winters, you may see significant die back on these plants. But don't give up on them right away. Cut away the dead branches and wait a bit. They are vigorous plants and often come right back when the weather starts to warm and the days are longer.

Hooked on Heuchera

Heuchera (pronounced HOO-ker-ah), also called coral bells, is a popular perennial in Seattle gardens. Each year, it seems, there are several new introductions to the collection available at nurseries, adding an ever wider selection of color and texture.

Some of the most familiar forms of this plant have purple leaves, as does this one above. Tiny, bell-shaped flowers are borne on tall slender stalks above the foliage in early summer. But it is the foliage that is the true star of the show, adding mounds of color nearly year around. In the purple range, look for varieties such as: 'Chocolate Ruffles,' 'Chocolate Veil,' and 'Garnet.'

Some varieties of Heuchera are noted for their veination patterns. I believe the variety shown above is called 'Pewter Moon.' Look also for 'Ruby Veil,' and 'Ring of Fire' to see other variations on the theme.

In recent years, Heuchera varieties with golden leaves have become very popular. Look for varieties such as 'Southern Comfort,' 'Peach Flambe,' and 'Caramel.'

Heuchera are easy to care for. Cut back ratty foliage in late winter, very early spring and a new flush of colorful growth will soon emerge. Because of the range of leaf colors and textures, these are good plants to keep in mind when you are designing a garden. Repeat the same plant 3 to 5 times throughout the garden, to draw the eye through the landscape, and to complement other colors in the garden. In Seattle, you often see Heuchera planted in mixed borders, containers and rockeries.

Viburnums

Some of these shrubs are David's and some are Marie's.
Others are known as Spring Bouquets or Snowball Trees.
Some have names like Korean Spice, Pink Dawn, and Highbush Cranberry.
Some are tall. Some are short. Some are evergreen. Some lose their leaves in a fiery display in fall.
Despite their differences, what these all plants have in common is that they are members of that large group of shrubs called Viburnums.

One of these in bloom now in Seattle is the Common Snowball (Viburnum opulus 'Roseum'). One look at these perfectly round clusters of flowers and you see where this plant got its common name. These shrubs can be trained into small trees, 8-10' high and 10-12' wide. Fall color is stunning most years, with those maple-like leaves turning deep rusty red.

My landscape design instructor used to say, "The trouble with common plants is that they are used commonly." I think of that quote when I see bedraggled specimens of David's viburnum (Viburnum davidii) used to edge the parking lot of a strip mall. These handsome evergreens deserve better treatment than they often get. With deeply textured, dark green leaves, a row of these shrubs make an attractive low (3-4') hedge. In spring, clusters of white flowers open from those pink branches you see above. The flowers are followed by iridescent blue berries in fall. V. davidii does very well in our acid soils and tolerates partial shade.

With very little care, these plants offer great reward in the landscape. I'm afraid that gardeners often avoid using them because they've only seen them used "commonly." I encourage you to explore some uncommon uses for this plant.

It probably comes as no surprise that I am partial to the viburnum that shares my name, Marie's viburnum, also called Doublefile viburnum (V. plicatum tomentosum 'Mariesii'). You can see this plant in bloom all over Seattle right now. Alas, I do not have room in my little garden for this shrub which gets about 10' tall and spreads a good 10-12' wide.

Here's a closer look at the flowers. Row upon row of these lace caps make this one very showy plant in spring. In fall, the leaves turn brilliant red before they drop.

Of course these are only three of the viburnums that grow in our area. Look also for V. x bodnantense, V. carlesii, and V. tinus. To learn more about these versatile and beautiful shrubs, I recommend Michael Dirr's book, "Viburnums: Flowering Shrubs for Every Season." (Actually, anything on woody plants written by Dirr would be a good addition to your gardening library.)

Rockery Plants - Part 2

OK, here's Part 2 of our virtual plant identification tour of Seattle rockeries.

This is Bergenia crassifolia, or winter blooming bergenia. It is also called "pig squeak" because the leaves make a squeaking sound if you rub them when they are wet. This is an evergreen perennial that requires little care. Just cut away old or cold-damaged leaves and faded flowers to keep it tidy.

These chartreuse flower heads belong to Euphorbia (I'm guessing this is a young specimen of E. chariacias wulfenii) a large genus of plants that includes the poinsettia (E. pulcherrima). Be careful handling these plants. They have a milky, white sap that is very irritating to the skin - I always wear rubber gloves when working with them, having been burned (literally!) in the past.

Along with them, a collection of English bluebells have taken up residence. Rarely planted on purpose, you'll find these cheerful blue flowers in gardens and rockeries everywhere in Seattle.

Speaking of blue flowers, these are grape hyacinths (Muscari sp.) These also happily multiply wherever they are planted. The red plant below them is a variety of Sedum.

Of course, rockeries are not all planted with ground covers and small perennials. When the planting pockets are large enough, small trees and shrubs can do quite nicely. Here at the top of the rockery is a weeping Japanese maple (Acer palmatum 'Dissectum Atropurpureum'), below it is David's viburnum (Viburnum davidii), and at the bottom, lavender (Lavandula sp.) is blooming.

Rockery gardening can be challenging because the planting spaces are often quite small and they dry out quickly in warm weather. Watering can be difficult because the force of the water stream can wash away some of what little soil is there. But after some trial and error, you will find a planting combination that will thrive with a minimum of care.

Missed the first part of the tour?
Go back to Part 1.

Rockery Plants - Part 1

As I said in my post on retaining walls and rockeries, Seattle is a city built on hills. Those hills are terraced with miles and miles of rockeries, which are planted, both accidentally and on purpose, with thousands and thousands of plants. Many of these plants bloom in spring, lining our streets with mini-explosions of color.

If you have ever wondered what any of these plants are, I'm here to help. In the next two posts, I'm going to take you on a little virtual tour of Seattle rockeries to help you identify some of the many plants you see blooming there this time of year.

This is a classic rockery plant combination: yellow Alyssum 'Basket of Gold,' paired with purple Aubrietia deltoidea. Aubrietia comes in both dark and lighter shades of purple; less common is a variety with deep rose colored flowers.

Candytuft (Iberis sempervirens) is a tough perennial with a long bloom time. It's one of the true bright whites (along with shotweed flowers) that you see early in the season. If you have this plant in your rockery, be sure to shear it after blooming to keep it from getting leggy. 

The red and green succulent plant spilling out onto the stairs is one of the many varieties of Sedum available in our area. Sedums are particularly well suited to life in a rockery because they require very little in terms of water, nutrients and care. 

The pink flowers on the left are heather (Erica sp.), the medium blue flowers in the middle are Lithodora, and the light blue flowers at right are periwinkle (Vinca sp). As with candytuft, all three of these should be sheared or cut back after blooming to keep them compact. In the lower left corner, new fronds, called fiddleheads, are emerging from a fern. To keep ferns looking tidy, cut away old, dried out fronds in late winter/early spring.

Wait! There's more:

Rockery Plants - Part 2

Picking Out the Pines

Do you have trouble telling one conifer from another? Do pines, cedars, firs and spruces all look the same to you? Well, after you read this post, you'll be able to tell the pines, at least, from all the others.

Here's how: pay attention to evergreen trees in your neighborhood this week. You'll notice that some of them have new shoots emerging from the tips of their branches that look like fingers pointing toward the sky.

These shoots look as if the tree is making the kind of rude gestures that humans do when they've been cut off in traffic. But don't take this personally, because these "fingers" are simply the beginnings of this year's growth for the pine tree. No other conifer produces shoots that look like these, so when you see them, you know the tree is a pine.

Over the next few weeks, these shoots, called "candles," will grow longer and shortly after that, new needles will appear along them. Depending on the type of pine, this will add anywhere from one to eighteen inches to the size of the tree.

You'll notice that some pines have white candles. (My guess is that these white shoots are what inspired people to start calling them candles.)

And that some have yellow candles. But they all work the same way.

You can shape a pine tree over the years by pinching the candles to stop or slow the growth of a branch. If you don't want a branch to add any new growth for the year, cut the candle completely off. If you want it to add some growth, but not too much, cut off just a portion of the candle. This technique is used in formal Asian gardens to train pines into a specific shapes.

As a bit of pine trivia, you might be interested in the fact that pine trunks offer a sort of record of the amount of rainfall from year to year. If you look closely at the tree on the left, you can see that there's bare trunk for several inches, then a whorl of branches, then more bare trunk, another whorl of branches, and so on. The distance from one whorl to the next is one year's growth. In rainy years, the trees grow more and the distance between whorls is longer; in drier years, it is shorter.





There are many pine varieties that grow well in the Seattle area. If you want to know more about them, the Sunset Western Garden Book has a lengthy section on types, growth rates, habits and more.

Favorite Plants: Solomon's Seal

One of my favorite woodland plants is beginning to unfurl in my garden right now. It is Solomon's Seal (Polygonatum odoratum).

This herbaceous perennial (herbaceous meaning that the foliage dies down in fall; perennial meaning that it comes back year after year) is always one of those great surprises in the garden in spring. Even though I know where it is planted, it is astonishing to see it rise up out of the ground in just a matter of days, from little pointy "noses" barely poking out of the soil to 4 foot tall arching stems.

The underside of the stems is lined with double rows of bell-shaped flowers that are slightly fragrant. The flowers fade in time, but the arching stems continue to grace the garden until late October, when the leaves turn yellow and fall, and the stems die back.

Solomon's Seal likes shady, woodland garden settings. The cultivar, 'Variegatum,' has white edges on the leaves and its stems are dark red when they first emerge.

This plant spreads via underground rhizomes. To propagate, divide clumps in early spring. You'll need a sharp shovel for this job, as the root/rhizome balls are dense.

This plant is in the same family (Liliaceae) as the Northwest native, False Solomon's Seal, but not in the same genus. If you are looking for the native at local nurseries, the botanical name is Smilacina racemosa. The plants are easy to tell apart when they are in flower. False Solomon's Seal has a conical spray of tiny white flowers at the end of each stem and no flowers under the stems. Without flowers, the plants look very similar.

Magnolia Stellata

In Latin, the word "stellata" means starry. (For more on Latin botanical names, look here.) Knowing this makes it easy to identify this small, shrubby member of the Magnolia family. Instead of the well known, cup-shaped flowers magnolias are famous for, this lovely little tree has flowers that look like stars.

In bloom right now in Seattle, these Star Magnolias are wonderful additions to small gardens and mixed borders. There are several varieties, all deciduous and slow growing. They can reach 10- 20 feet high, with a spread from 10- 20 feet. Be sure to check plant labels for specific sizes before you buy one.

These trees add interest to the winter garden with a profusion of fat, fuzzy flower buds that resemble pussy willows. The buds open in early spring with flowers that light up the landscape and, depending on the variety, scent the garden with a light fragrance. Most trees have white flowers, but there are pink forms as well.

As with all flowering plants, it is best to buy them in bloom to be sure you get the color and fragrance you want. If you can, plant this magnolia where you can see it from your window because it is truly one of the stars of the spring garden.

Sweet And Sour Fall Color

We are having a particularly rainy and windy fall in the Seattle area this year, but don't let that keep you from enjoying the vivid colors of the season. For example, look for two of my favorite trees for fall color: Sweet Gum (Liquidambar styraciflua) and Sourwood (Oxydendrum arboreum).

Native to the eastern US, sweet gums are attractive trees that can grow to 60' tall, 20-25' wide. They are sometimes mistaken for maples because their leaf shape is similar.

In fall, these leaves turn color in multiple shades: burgundy, red and yellow. Certain cultivars, such as 'Festival' and 'Roundiloba' are especially showy with bits of peach and orange mixed in with the purples, reds and yellows. These trees are stunning! If you are fortunate enough to pass one on your daily rounds, watch as the leaves progress through color changes as the days go by. They'll take your mind off the rain.

Sourwoods are also native to the eastern US. They are much smaller than sweet gums, taking several years to reach a height of 20 - 30', making them good trees for urban yards. I don't think they are planted nearly enough here. They are well suited to our acid soils and cool summers.

Sourwood leaves remind me of fruit tree leaves, like apples or peaches. But in fall, unlike the leaves on fruit trees, sourwood leaves turn brilliant red, orange and black-purple. The display is even more of a head-turner because in late summer, and early fall, these trees produce drooping clusters of white, bell-shaped flowers. (They are in the same family, Ericaceae, as the Strawberry tree.) These flowers make sourwoods easily identifiable this time of year. They are said to be fragrant, so get up close; fall breezes quickly carry the scent away.

In spite of rain and blustery weather, this is a good time to get outside and observe the change of seasons. In the Northwest, we are blessed to have a huge variety of trees with different growth habits. We have longer, more colorful autumns than other parts of the country because as one group of trees fades, another begins to color up. Most years, this means that we have close to three months of color. Enjoy it!

If you live in the city of Seattle and need a good tree guide, consider Arthur Lee Jacobson's "Trees of Seattle: The Complete Tree-Finder's Guide to the City's 740 Varieties." This book has become a classic, and for good reason.

Trumpet Vine, the Last Blast of Summer

As the first day of autumn is rapidly approaching and most of the blooms in the garden have faded, my trumpet vine is flowering with an exuberance that is positively spring-like. Trumpet vines (Campsis radicans) are vigorous plants that typically scamper up to 40 feet or more in just a few seasons. They cling to arbors and walls with aerial roots.


Most trumpet vines sport red-orange tubular flowers as you see above, but there are a few newer cultivars, such as one called 'Flava,' that have yellow flowers. Much loved by hummingbirds and bees, these vines attract wildlife and pollinators to the garden. (To learn more about landscaping for wildlife in our area, check out "Landscaping for Wildlife in the Pacific Northwest," written by Russell Link, wildlife biologist with the Washington Department of Fish and Wildlife.)

In some parts of the country, trumpet vines can be invasive, but I have not found that to be the case in the Seattle area. Vigorous pruning may be required to keep a vine in bounds, but that's only necessary once, maybe twice, a season.

Daylilies

Daylilies are called daylilies because each flower is said to last only a day. Although the flowers look like true lilies (Lillium sp.), daylilies are in the Hemerocallis family. If you have trouble telling them apart, simply look at the stems and leaves.

Daylilies have long, strap-like leaves, with flowers borne on long, leafless stems. True lilies are bulbs with a single long stem. True lilies have leaves along the stem.

Daylilies come in many colors and sizes and are among the hardiest of perennials. They aren't terribly fussy about soil, but, of course, will do best in beds with good drainage that have been amended with organic material. Water during dry spells.

In the northwest, plant or divide daylilies in early spring or fall. Clumps will spread over time and for best bloom should be divided every few years.

Most daylilies bloom late spring early to mid-summer for a period of days to a few weeks depending on weather. A few will bloom throughout summer, such as this charming yellow, dwarf variety called 'Stella d'Oro.'

For more information on daylilies, take a look at Diana Grenfell's book "Daylilies," part of the Gardeners Guide series.

Lewisia

Years ago, a friend of mine, who then owned a small native plant nursery, asked me to help with her booth at a plant sale at the Bellevue Botanical Garden. At the time, I didn't know much about Northwest natives and I thought it would be a good way to spend some time with her and learn more.

As we unloaded her truck, she pointed to a flat of plants. "These are Lewisia," she said as if I should know the significance of that. "Keep an eye on them or they will disappear," she added, somewhat sternly. I looked at the plants. They didn't look like anything special. None were in bloom. The leaves formed a flat, fleshy rosette that looked like they could be related to Echeveria (hens and chicks). Surely she didn't mean that anyone would steal one of these when we weren't looking?!

We set up our display and she brought out signs with descriptions of the various plants, and for those not in bloom like the Lewisia, photos of the flowers. When I saw the photos, I began to understand why these plants might be of interest. These beautiful little alpine flowers will stop you in your tracks.

What I also didn't realize was that very few people at that time propagated Lewisia for sale. They weren't available at nurseries then (although the L. cotyledon you see in the photo above is one I bought at West Seattle Nursery several years ago). You would have to go up into the mountains, as she had, and collect seed or get the seed from someone who had. Getting the seed wasn't even half the battle. These plants aren't easy to grow. They need sharp drainage and a fair amount, but not too much, sun.

Of course, the plant enthusiasts at the sale that day already knew all of this. Once the sale began, word spread rapidly that we had Lewisia for sale. A crowd gathered. My friend could have sold that flat of plants 10 times over! She said she would sell only one plant to a customer. She knew how hard they were to grow and felt that if several gardeners each got a plant, there was a greater likelihood that some plants would survive than if just one or two people got them all. There was a lot of pleading and begging going on, but she stuck to that policy. We sold out of Lewisia in mere minutes.

Lewisia is much more available today than it was back then. But it still isn't easy to grow. That doesn't mean you shouldn't try. If you are interested and have a sandy, rocky spot, buy a plant and see what happens. Every summer when my Lewisia blooms, I'm glad I did.

If you'd like to learn more about Pacific Northwest native plants, I recommend Arthur Kruckeberg's classic reference, "Gardening with Native Plants of the Pacific Northwest."