A Gardening Journal

Cardinal willow

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What's this?  The twigs at the top of this bush are aflame with color.  More, please!

 

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Just as dramatic is how boring the bottom stems are.

 

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It doesn't take long for a given twig to progress from beautiful to boring, either.  In the picture below, the twig at the top, as well as the twig I'm holding, are both much more orange than the older growth at the bottom, whose orange color is fading out.

 

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And in fact, the twigs of this shrub—the cardinal willow, Salix alba 'Cardinalis'—are only at their best during their first Winter.  Starting the next Spring, their bark begins to fade out to tan, just like it has done at the second-year growth at the bottom of the picture.

 

How to grow a willow tree where no twigs survive longer than a year—but year after year, a huge crop of new twigs is also produced?  It take only minutes of well-timed intervention annually.  Read on!

 

 

Here's how to grow this remarkably colorful willow:


Latin Name

Salix alba  'Cardinalis'

Common Name

Cardinal willow

Family

Salicaceae, the Willow family.

What kind of plant is it?

Deciduous tree.

Hardiness

Zones 2 - 8.

Habit

Multi-stemmed and broadly upright.

Rate of Growth

Fast. 

Size in ten years

'Cardinalis' is much smaller than the straight species, which, depending on conditions, could be twenty to forty feet tall and ten to twenty feet wide after a decade, and can mature, potentially, to a hundred feet tall and wide.  'Cardinalis' matures to a petite fifteen to twenty feet tall, and is half that in a decade. 

Texture

Medium; the narrow foliage is densely held. 

Grown for

the bark on the twigs that grow in Spring and Summer, which becomes brilliant yellow and orange when cool weather arrives in Fall and stays colorful until warm weather returns in Spring.  The transition is only effective once.  In its second year, the bark becomes increasingly overlaid with milky and light tan colors, and after that it remains light tan year-round.

 

its vigor: Cardinal willow grows fast, especially when it has access to a lot of water.  Production of new twigs can be remarkably strong.

 

its amenability: the display of Winter bark is most effective when the tree is pruned drastically.  See "How to handle it" below.

Flowering season

Early Spring, before new leaves expand.  The flowers are typical pussy-willow catkins.  They are showy but not more so than those of other willows.

Color combinations

Cardinal willow goes with everything.  When the leaves are out in Spring and Summer, the tree's color is mid-green.  Few gardens in Winter can be so color-specific that the presence, anywhere, of a plant with brilliant orange twigs would be discordant.

Partner Plants


As with all bushes and trees with colorful twigs, evergreen underplanting and backing are always the best.  Quick-growing vines or rambling shrubs could ornament the tree in the Summer months.  See the suggestions and concepts for partner plants for Acer negundo 'Violaceum', another tree best handled by severe Spring pruning.  See "How to handle it" below, for strategies on that pruning.

Where to use it in your garden

Salix alba 'Cardinalis' is only colorful in the cold months—but it's also a bore in the warm months.  So this is a plant that you'll want to plant so it's accessible for viewing when the weather's wet and sloppy—but still not plant it in such a prominent location that its bland warm-weather appearance is a day-by-day tedium. 

 

Similarly, this isn't the tree to grow as the main focus of your garden even though its Winter appearance is strong enough to suggest that.  Instead, plant it as a secondary focus, so you can ignore it in the Summer.  This is also prudent in case the tree contracts one of the numerous ailments to which willows are prone; see "Downsides" below.  If it dies, your overall garden isn't impaired.  

Culture

Full sun and any decent soil.  Growth is quickest when there's plenty of water available.  Salix alba will grow by fresh water, and tolerates seasonal flooding, too.  Gardens with heavy soil are great for willows, because that soil usually has difficulty draining.  

How to handle it:  The Basics

Because 'Cardinalis' is at its least interesting in Summer, when the twigs aren't colorful and the mid-green foliage is out, it's best to minimize the plant's size.  Happily, that's also the way to maximize the intensity of young twigs' color in the cool weather from Fall through Winter and into Spring. 

 

Prune at the end of the colorful lifespan of the new growth, whose bright orange show you'll want to enjoy every day of.  If you're interested in the display of pussy willows, wait until after they're done, and so prune in mid-Spring.  If not, prune anytime in late Winter or Spring that's convenient for you.  Your pruning will only encourage that season's new growth, which will become the next generation of fabulously-colorful twigs during the coming Fall, Winter, and early Spring.

 

You have two choices when pruning.  If you cut all the branches down as low to the ground as possible each Spring, the new twigs will sprout from the stubs of the old twigs and directly from whatever stump has been allowed to develop.  You'd be growing the willow tree as a willow shrub.

 

The new growth formed in response to such pruning can be much longer than that formed by an unpruned tree.  Instead of being just a foot or two long, these new twigs could be four, six, or even eight feet long.  While a willow grown as a shrub is much smaller than when grown as a full-size tree, it's still, potentially, a very big shrub.

 

The shrub is the smallest if you cut it back every Spring, but the display of twigs is still acceptably bright even if you cut back only every other Spring.

How to handle it: Another option—or two?

You could also have the entire display of orange twigs originate a bit higher off the ground.  Instead of pruning all branches to the ground, let just one branch grow, but prune any others to the ground without mercy. That one branch will become the trunk of your tree. 

 

You set the height of your young tree's trunk by pinching it when it's tall enough, so it then concentrates on growing branches.  But what height is "tall enough?"  The plant itself provides the answer.

 

Willows that undergo the radical and annual pruning that you're planning to do will put out an unusual number of new twigs, and there just isn't room for all of them to grow upward, or even horizontally for a bit and then upward.  The lowest new twigs will have no choice but to grow downward.  This means that the new twigs will naturally form a complete sphere of growth.  Marvelous!  But this also means that if you don't grow the trunk high enough, the bottom twigs will grow right to the ground.  A complete sphere of growth is ideal, but that's only possible if it's got enough clearance—if, in other words, your trunk is high enough. 

 

It would look odd if the sphere were merely tangent to the ground, or even just a foot or two above it.  Keep in mind that the radius of the sphere is the length of those new twigs.  The trunk of your tree needs to be as tall as the maximum length of the new twigs, plus another few feet so there's some clearance between the bottom of the sphere and the ground.

 

To my eye, it's best to think in thirds.  The top of the sphere is the top of the tallest twig that grows straight up from the growth point at the top of the trunk.  The bottom of the sphere is as low as the end of the twig that grows straight down from the growth point.  Make the trunk twice as high as the longest twig, so the sphere will always be that twig-length off the ground.  In this way, the portion of the trunk visible below the sphere of twigs will be a third the tree's overall height.

 

Practically speaking, this might not be strictly achievable.  If twigs can grow to six feet long—entirely possible—that would mean that the trunk would be twelve feet high.  Twelve feet is about what I can comfortably and safely reach when standing on the second step from the top of an eight-foot step-ladder.  And I'm 6.3" barefoot and with wet hair.

 

But try to have the trunk be no shorter than ten feet or, by late July, you might have to prune off the lower twigs.  With a high-enough trunk, you need prune only that one time in the Spring.  To me, this makes a high-enough trunk worth it even if it also means I'd need to get a really tall stepladder.

 

So, then, let just one branch of your young willow grow to twelve or even fifteen feet tall all on its own.  If the branch isn't vertical naturally, stake it.  Young willow branches are extremely flexible, so this is comparatively easy.  The goal is that the "trunk-ette" be a couple of feet taller than the target height you'll prune it to.

 

The very next Spring (or even late Winter; sometimes you just can't wait to get going, I know all too well), prune (or lop or saw) the trunk off at ten or twelve feet tall.  Let all the branches at the top two feet of the trunk sprout freely and grow unimpeded the rest of the reason.  At the same time, be vigilant in pruning off both branches and new shoots that arise anywhere below.

 

The next Spring, cut all of the previous year's growth back to an inch or two; completely cut off most of the branches that had arisen from the lower portion of the top two feet of trunk, from which you had allowed anything at all to sprout the year before.  Let the new growth from the top foot of the trunk grow unimpeded the rest of the reason.

 

Each Spring thereafter, cut the previous year's growth from that top foot of the trunk back as far as possible; you won't need to leave actual stubs, because the entire trunk will swell into a grotesque (but in an attractive way) knobby mass from which this new growth will spring directly.  Your willow standard is now launched for the long term.

Quirks or special cases

None. 

Downsides

Like all willows, Salix alba can be slain by any number of pests; there are bacterial as well as fungal infections that can be fatal, and plenty of insects that, potentially, can show interest in every part of the tree, from foliage to roots.  It would be foolish, then, to rely on Salix alba to be your garden's principle tree, or even to be a main feature as a coppice or pollard.  Yet another advantage of a coppice or pollard is that the tree is kept much smaller; if it does die, it's a smaller loss, and much less dead wood to remove.   

Variants

There are some very showy cultivars that will always be more garden-worthy than the species itself.  The leaves of 'Sericea' are white-woolly top and bottom; the tree is a glorious silver presence in the garden.  'Aurea' has yellow leaves as well as stems.  The young stems of 'Britzensis' (which is probably the same as 'Chermesina') are also orange-red.  'Tristis' is a yellow-stemmed weeper.  'Vitellina' has yellow stems and green foliage. 

 

The colorful stems of all are enhanced by the same coppicing or pollarding. 

Availability

On-line and, occasionally, at retailers.

Propagation

By cuttings.  Willow seed is viable only briefly, which is why it doesn't show up in seed catalogues.

Native habitat

Salix alba 'Cardinalis' is native to Europe and Asia.  

 
 
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