Designing Gardens with Foliage Color

If you want color in your garden all year around, I suggest that you think in terms of foliage colors first and then use flower colors as accents.

Why not plan around flower color? Because the flowers of perennials and woody plants don't last very long. You wait all year to see those beloved peonies or rhododendrons or daylilies open up. When they bloom, the flowers last anywhere from a few days to a couple of weeks and then that's it for the year.

You can add color to the garden for a longer period using annuals, but replacing them every year and keeping them looking good can be an expensive and high maintenance project. 

To get ideas, look at gardens in your neighborhood. Here you see a lot of color and not a flower in sight! 

Visit public gardens, too. This photo was taken in the Coenosium Rock Garden at South Seattle Community College. The garden features an outstanding collection of conifers and look at all that color! There's the blue Atlas cedar (Cedrus atlantica), the kelly green of the dwarf Alberta spruce (Picea g. albertiana 'Conica'), yellow green of deodar cedar (Cedrus deodora), and pines (Pinus sp.) in various shades of green.

Foliage color may be deciduous like the purple smoke tree (Cotinus coggygria), or evergreen like the heavenly bamboo (Nandina domestica 'Moon Bay') shown above. 

Look also for variegation in foliage, like this iris.
Many plants have colored edges on their leaves, like Daphne 'Carol Mackie' or Hebe 'Red Edge.'

And don't forget grasses. Here you see Japanese forest grass (Hakonechloa macra) on the right and bronze leather leaf sedge (Carex buchananii) at the left. If you want more blue in your landscape, look for blue oat grass (Helictotrichon sempervirens) or blue fescue (Festuca glauca 'Elijah Blue').

Need more ideas? "Consider the Leaf: Foliage in Garden Design," by Judy Glattstein goes much more in depth. She writes in a comfortable, conversational style, making it enjoyable to learn from her about how to bring lots of color with less effort into your garden. 

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.)

Commercial Landscapes: At PCC, A Dry Stream Runs Through It

This is the first of what I intend to be a series of posts highlighting commercial landscapes done well. This time I am featuring one of my favorite grocery stores, the West Seattle PCC.

For those of you unfamiliar with this store, PCC stands for Puget Consumers Co-op. With 9 stores in the area, it is the largest community-owned and operated natural food retailer in the US. Because of the co-op's mission, it is no surprise that the block-long parking strip running from California Ave SW to 44th Ave SW has been made into a colorful garden. What is surprising is that, despite being a high traffic area, this garden looks good all year around, year after year.

One reason for its success is that it has a central design element that ties it all together. That element is the dry stream bed that has been constructed down the center. Large pieces of granite flank the sides, with river rock filling the depression down the middle. Planting areas are bermed slightly on each side to accentuate the stream bed effect.

Another reason for this garden's success is that it is colorful. Here we see the yellow of Spirea 'Goldflame' in the foreground. Other plants that add color include: Rosa rugosa, Oregon grape (Mahonia sp.), ornamental grasses, and heathers/heaths. Plus, there are various shades of green found in the Mugo pines, Alpine fir, kinnickinnick and other ground covers.

Two driveways cut through this garden to allow access to the store's parking lot. As a driver who goes in and out of there often, I appreciate the fact that none of the plants are tall enough to obstruct my view of oncoming traffic. This is something for homeowners to keep in mind if they decide to convert their parking strips to planting strips.

Are there commercial landscapes in your Seattle neighborhood that you particularly appreciate? I'd love to hear about them.

Here's the Dirt: Part 2 - Different Types of Soils

When we talk about types of soil, we are usually talking about whether the soil is predominantly sand, silt or clay. It is important to know the difference because gardening in sandy soil is quite different from gardening in soil that is mostly clay.

The reason for this is that the size of the soil particles is very different. A particle of sand is much bigger than one of silt, which is much larger than a particle of clay. To illustrate this, I've lined up some items on the windowsill to help you get a visual sense of the differences.

The cherry tomatoes on the left represent the large particles found in sandy soil, the rice (center) is like the much smaller particles of silt and the flour, at right, has tiny particles similar to clay. (Don't hold me to these exact proportions: this photo is just to give you way to think about this.)

Now imagine what happens when it rains. If you have sandy soil, it's like putting the cherry tomatoes in a colander and running water over them. As soon as you turn off the faucet, water runs right through those big pore spaces, leaving just a thin coat of moisture on surface of the tomatoes. If you are gardening in sand, you know this - without organic material added to the soil to soak up and hold onto water, it dries out in no time. 

You can think of silty soil as being like the grains of rice. When you run water over rice, it drains slowly, leaving quite a bit of moisture both coating the grains and held in the small spaces between them. 

Clay particles behave a lot like flour. They are so tiny that they pack in tightly together with very little space between them. If you pour water on flour, it will just sit there until you mix it in. Once you've mixed it in, however, it is very hard to completely dry it out. 

OK, so that's how soil particle size affects water retention. Particle size also matters when it comes to nutrients. Ions of nitrogen, potassium, phosphorous, calcium, magnesium, sulphur, etc. cling to the outer surface of soil particles where they can be taken up by plants. Smaller particles, like silt and clay, have far more surface area per volume than those big particles of sand and therefore can hold a lot more nutrients. 

Bear in mind that this is a very simple explanation of soil types. It is enough information to help you make some reasonable decisions about how to improve your soil, which I'll talk about in the next post on soil amendments. But it by no means covers the subject. Healthy soil is more than particles, it includes organic material and many living organisms working together. I strongly recommend that gardeners learn more about that fascinating world under our feet. James Nardi's book, "Life in the Soil: A Guide for Naturalists and Gardeners," is a good place to start. 

Remember that unless you are right on a sandy beach, your soil is likely some combination of particles. If you aren't sure whether it is mostly sand or clay, you can do the "squeeze" test. Pick up a handful of moist soil and try to make it into a ball. If it packs nicely into a ball, it has a lot of clay in it. If it crumbles without holding a shape, it is mostly sand.

Wondering how much mulch, soil or compost you should buy for your gardening project? Check out this handy table.

Read part 1 of this series - Here's the Dirt: Introduction

Here's the Dirt: on Soil, Compost and Mulch - Introduction

When you go to a garden center, you'll find lots of bagged goods with names like potting soil, planting soil, top soil, bark, fine bark, play chips, compost, mushroom compost, planting compost, etc. There's chicken manure and steer manure and bat guano (more manure). Some companies sell three-way and five-way mixes of various ingredients that claim to be excellent growing media.

With so much available, how do you choose which, if any, of these products are right for your garden? The first step is to understand what these materials really are. There's a lot to say about some of them, so I'm going to do a series of posts to tell you about soil, soil amendments, compost and mulch.

First up - soil. 
Soil, also called dirt, is the foundation of your garden. The health of your soil determines the health of the plants you grow. If you are at all serious about gardening, particularly if you plan to grow some of your own food, you owe it to yourself to learn about the soil you have and how best to maintain its tilth or health.

Technically, soil is a combination of sand, silt and clay particles with some amount of organic matter mixed into it. There is no precise recipe for soil. The soil you have is the product of the wind, weather and geology of your area.

Thanks to the action of glaciers long ago, soils in the Seattle area are varied. Some of you are gardening in sandboxes. Some of you are trying to break up clay. If you are gardening in an area along a river, you might have silt. Many of you are finding rocks the size of your fist nearly everywhere you dig. All of these scenarios are the gifts of what is called "glacial till."

The combination of sand, silt and clay particles you find in your garden is what makes up the structure of your particular batch of soil. Organic material comes and goes over the seasons. Nutrients and water are taken up by plants. Depending on the health of your soil, microscopic organisms thrive or struggle. Through it all however, year after year, those sand, silt and clay particles remain, providing the stage where all the rest is played out.

There are many things you can do to improve your soil, but there is nothing you can do that will change the type of soil you have. A clay soil, for example, cannot be changed into sandy loam, no matter what you add to it. (In fact, as I'll explain in a later post, adding sand to clay is a bad idea.) Your best bet is to know what type of soil you have, what its characteristics are and how to make the most of what you have.

In Part 2 of "Here's the Dirt," I explain more about soil types.

Wondering how much mulch, soil or compost you should buy for your gardening project? Check out this handy table. 

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.

When Is The Right Time To Prune?

I recently wrote a post about pruning roses. But what about the rest of the plant material in your garden?  When is the optimal time to prune those plants? The right time to prune depends on the plant. Here are some general guidelines.

Winter pruning (January, February)
In general, prune dormant, deciduous plants in winter, such as:

• Deciduous ornamental trees
• Fruit trees - note that these are pruned very differently from ornamental trees to maximize fruiting spurs. Be sure to consult a pruning guide before proceeding.
• Roses - there are different types of roses and each is pruned differently
• Wisteria is cut back hard in winter and then again in summer after blooming
• Certain vines - check pruning guides for when and how
• Winter is also a good time to prune conifers (pine, fir, cedar) to minimize sap "bleeding."

Early spring (March, April)

• Hydrangeas (shrub form) after frost danger is past
• Most hedges, such as laurel, privet, Leylandii cypress
• Red and yellow twig dogwoods are cut back hard now to stimulate the colorful new growth that will light up next winter's landscape

Late spring, early summer pruning
In general, prune spring blooming plants right after they bloom. Pruning them earlier often guarantees that you cut off all the flower buds and miss out on that year's display. Specific plants include:

• Rhododendrons - these and many other plants start setting flower buds shortly after the current flowers fade, so don't dilly dally. If your rhododendron needs shaping, get to it right after bloom so the plant has time to set flower buds for the coming year.
• Camellias
• Forsythia
• Rock Rose
• Peonies
• Pieris
• Shear spent flowers on herbs such as lavender, rosemary, thyme and oregano

Summer pruning

For the most part, summer pruning is a matter of deadheading and light trimming. Some people give their Japanese maples a bit of a hair cut in summer, because they get so twiggy, but that's optional. 

Fall pruning

Avoid this practice. I know many people were raised in households where pruning trees and shrubs was part of fall cleanup and preparation for winter, but it is not a good horticultural practice. All pruning stimulates growth and new growth is very susceptible to cold damage. If a plant is exposed to a sudden, early freeze, as we've had in Seattle the past three or four years, the new growth may be killed and the overall health of the plant jeopardized. 

What about storm damage?

Remove dead, broken or damaged branches any time of year.

These are very basic guidelines. For more specifics I refer you to the American Horticultural Society's book, Pruning and Training and Cass Turnbull's Guide to Pruning. Be sure you have proper tools, and if you are handling roses or berries, a pair of thorn resistant gloves. 

3 Pruning Tools You REALLY Need (and 3 That Are Optional)

To prune properly, you need very sharp tools so that you can make clean, precise cuts. This is important because jagged cuts and torn bark provide good avenues for insect infestation and disease. To do the job well, you don't need lots of tools, you just need good ones.

Here are my well-used  favorites, the tools I use for 95% of the pruning I do. At top, my 19 year old hand pruners, a folding saw and a pair of bonsai scissors.

Here's why these are the must-haves:

• Hand pruners. Unless you are doing significant tree work, most of the pruning you'll do is with hand pruners. It is worth it to spend a little extra money on pruners that feel good in your hand and are sturdy enough to last. Felco is the brand I prefer because they offer high quality and a choice of sizes and features. The pair I have is designed for small hands like mine. I no longer get cramps from trying to use pruners that are too big for me.  Felcos come in larger sizes, of course, and there's a version for left-handed gardeners, too. All of these are bypass pruners, which are preferable to anvil pruners because they make cleaner cuts. Anvil types tend to crush stems, especially as they lose their sharpness. 
• Folding pruning saw. I like folding saws because you can fold them up and slip them into a pocket (or a tool holster) to keep them handy. They are small and easier to maneuver in cramped spaces than larger saws. These saws are fine for cutting branches up to 2-1/2" - 3" diameter. Better brands have blades that can be replaced. 
• Bonsai scissors. When I bought these scissors 15+ years ago, I didn't think they would be as useful as they have turned out to be. They are ideal for tip pruning shrubs and roses. I use them to deadhead pretty much everything, including bloomed-out herbs like lavender and thyme. They are the perfect tool for deadheading rhododendrons because the pointy blades can slip into the tight space at the base of the faded flower without damaging the new growth emerging below it.

OK, those are the "must haves" -- now here's a few tools that you might need for specific situations. If you are a beginning gardener, add these as you come across a project they are suited for. There's no need to spend money on them until that time. None of these are precise tools. The length of the handles of loppers and pole pruners can make for wobbly cuts. The bow saw is hard to maneuver in tight places. You use these in cases where you want to remove lots of foliage and branches quickly so you can get to the specific areas where you will make precise cuts with smaller tools.

• Loppers are excellent for projects like clearing out blackberry overgrowth or dismantling shrubs you want to remove. They are also good for "lopping" off big hunks of foliage and get them out of the way so you can  get to the place along the trunk where you need to cut off a branch.
• Bow saw. Bow saws are best used to make quick work of large diameter branches. They can be a bit unwieldy because of their size and shape, which can make for irregular cuts. Good for clearing away storm debris or removing trunks and branches of trees you want to remove. 
• Pole pruner. Again, these are tools that have some use if you need to remove the outer portions of broken branches. But it really isn't possible to have precise control over a cut made holding a tool with such a long handle - there's going to be some wobbling going on. That said, there are places where ladder work is not practical (slopes, e.g.) and these pruners might be the best or only choice. 

There you have it, the lowdown on pruning tools. There's just one more thing to add -- good information on how to prune. If you live in the Seattle area, consider getting some hands-on training from Plant Amnesty. Check their website to find out when and where classes are being held. Or get a copy of Cass Turnbull's pruning guide, which is the next best thing. Cass is the founder of Plant Amnesty.