Louis Raymond experiments in his own gardens like

a mad scientist, searching out plants that most people have

never seen before & figuring out how to make them perform.- The Boston Globe

…Louis Raymond ensures that trees can grow in Brooklyn…

or just about any other place where concrete consumes

the dirt and skyscrapers shield the sunshine.- USA Today

 
 

NEW Trips to Take!

Myrtle's easy when the conditions are right.

 
 
 
 

NEW Plants to Try!

Louis tries to capture the exact words to describe the fleeting but deep pleasures to be found in these Summer-into-Autumn incredibles.

 
 
 
 

New Gardening to Do!

Allergic to bees? You can still have an exciting garden, full of flowers and color and wildlife.

 
 
 
 

Plant Profiles

Variegated Weeping Korean Dogwood

The bracts of Korean dogwoods can be effective for a month or more. Even so, by July they're done. Variegated foliage keeps up the interest, in Spring before the bracts have emerged, and Summer into Fall, after they're gone.

 

 cornus-kousa-kristin-lipkas-variegated-weeper-close-up-with-flowers-640

  

All of the hundred-and-more cultivars of Korean dogwood flower; nearly a score have variegated foliage. Only one has this talent: a weeping habit. Growing free range, the branches cascade to the ground. Year by year, the result is a mound of growth that's higher than it is wide.

  

I'm taking advantage of the flexibility inherent in most weeping branches by training a pair of these variegated dogwoods into a tall and wide arch.  The arch spans a narrow opening through the boxwood hedge that surrounds a side garden. These dogwoods are about six years old. In another two years, their top branches will meet at the crest of the arch, nearly nine feet above ground.

  

cornus-kousa-kristin-lipkas-variegated-weeper-overall-072713-640

  

In late Summer or Fall, the season's pendulous new stems will be tied to the arch so that they point up the arch, not out into space or down to the ground. This is easiest to do starting at the top and working downward. Then each lower rung of stems is tied over the bottom portion of the just-tied-in stems above. In the process, I cut off last year's twine before adding this year's. 

 

cornus-kousa-kristin-lipkas-variegated-weeper-overall-072713-top-of-arch-640

 

This cultivar also has the longest name of any Korean dogwood: Cornus kousa 'Kristin Lipka's Variegated Weeper'. As if we didn't know the foliage was variegated or the habit is weeping, the name is lengthy as well as didactic. It's the only cumbersome feature of this unique plant. And who is Kristin Lipka? The daughter of the nurseryman, Bob Lipka, in whose collection of Korean dogwoods a sport of this marvelous tree first appeared.

 

Here's the arch two years ago, just as the tips of the two legs were—finally!—about to touch.

 

Here's how to grow this exceptional Korean dogwood:

 

Latin Name

Cornus kousa 'Kristin Lipka's Variegated Weeper'

Common Name

Variegated weeping Korean dogwood

Family

Cornaceae, the Dogwood family.

What kind of plant is it?

Deciduous hardy tree.

Hardiness

Zones 5 - 8.

Habit

Growing free range, a strongly weeping mound, narrow to start and, so far, remaining narrower than it is tall. Easy to stake higher and higher. See "How to handle it: Another option—or two!"

Rate of Growth

Medium to fast.

Size in ten years

If unstaked, a mound five to six feet wide and eight to ten feet tall.

Texture

Lively and detailed, becoming dense as the tree matures.

Grown for

its foliage: Each blue-green leaf has an irregular perimeter of creamy white.

its bracts: Each small sphere of tiny yellow flowers is backed by a showy quartet of white bracts. Because they are clearly white, not cream, the bracts show up well against the busy variegation of the foliage.

its habit: Branches weep strongly; they are slender and very flexible when young, but become thicker and more rigid with age. 

Flowering season

Late Spring into early Summer: June here in southern New England.

Color combinations

The mature foliage goes with everything. Pink tends to creep into the bracts as they age and, sometimes, into the emerging leaves, making the best location for Kristin one that is either neutral greens and whites, or has some pink in the tree's near neighbors.

Plant Partners

With such colorful foliage, striking form, and showy flowers, 'Kristin Lipka's Variegated Weeper' benefits from a context with plenty of neutral and even boring horticulture. Then there will be a helpful backdrop already in place, before which the the dogwood can create jazzy energy. My arch is immediately inside a perimeter hedge of boxwood, whose small, shiny, green leaves persist year-round, and whose heavy dense habit makes the dogwood arch seem all the more light and high-flying. Immediately on the other side of the arch is a low horizontal rail—of curved rebar, like the arch—upon which I'm training young weeping ginkgo trees. Their foliage is fan-shaped and, in this cultivar, solid green, for a second simple-and-strong contrast to both the dogwood arch and the boxwood hedge behind it.

 

Companion plants for weeping trees that are allowed to grow naturally are problematic if the tips of the trees' branches grow long enough to reach down into them. The upward thrust of most plants' growth seems to be sparring with the downward droop of the pendulous tree branches. Plus, overlapping growth of other weeping trees can become so dense that underplantings eventually become smothered. The branches of some pendulous species, such as Cercis canadensis 'Covey' don't stop when they hit the ground, either. They grow outward, like flowing water, smothering a wider and wider area of companion plants. It isn't possible or even desirable that weeping trees always be trained high enough, or their lowest branch tips kept clipped up, to maintain clearance between their dome-like canopy and their underplantings. And, anyway, the outward-flowing canopy of a mature 'Covey' is among the tree's best features.

 

One solution is for underplantings to be of maximum thickness but minimum height, to suggest a carpet, or at least a shag rug, for the pendulous branches to tumble down onto. Vinca, pachysandra, hardy ginger, and liriope are all possibilities. Another solution is to take advantage of a weeping tree's inherently flexible growth by training the entire tree upward or outward. Then its lower branches are safely out of reach from companion plantings, while the overall form is much rarer and more distinctive than any natural-growth mound.

Where to use it in your garden

This cultivar is showy in form as well as foliage, so site it prominently. If you're letting the tree weep naturally, its branches will quickly reach the ground; the canopy will eventually broaden, because branches will stack up atop each other, and also because, with farther downward growth stopped, their side branches will tend to sprout and grow outward. Could you site the tree atop a retaining wall or a steep slope, and provide additional clear footage through which branches can continue weeping downward? 

Culture

Plant in Spring or Fall, ensuring enough water for establishment. Kristin enjoys full sun as well as part shade, but grows faster with more sun. Cornus kousa is tolerant; almost any soil and siting that provides decent drainage and moisture retention is likely to be acceptable. 

How to handle it: The Basics.

'Kristin Lipka's Variegated Weeper' needs no formative pruning or training if you're letting it grow free-range. Just keep any vining weeds from twining up its all-too-conveniently pendulous branches, which will brush the ground and provide ready upward access. And provide outward space so the expanding canopy can develop naturally.

How to handle: Another option—or two!

Branches of weeping trees typically become pendulous quickly as they grow because, at least when young, they have less rigid internal structure. They are unable to support the weight of their lengthening growth, which soon droops downward. "Less rigid internal structure" is another way of saying "much more flexible" and, so, the branches of weeping trees are also unusually easy to tie to external supports. Even though their natural tendency is to droop lower and lower, they are naturals for training higher and higher. 

 

If you'd like to provide a weeping tree with a greater opportunity to weep, and you don't have the option of planting it at the top of a retaining wall so branches can keep growing downward instead of hitting the ground, you can easily grow the tree to a higher elevation from which its weeping can begin. Tie one or more of the flexible young branches to a sturdy vertical stake; depending on the plant, your stake, and your ambition, you might be able to lead stems upward just a couple of feet, or a couple of yards. Use a permanent stake; although branches of weeping trees do become more rigid as they grow thicker with age, the strength of their wood is usually never the equal of that of their non-weeping brethren.  My favorite training stake is reinforcing rod, it is readily available in lengths up to twenty feet.

 

A pair of weeping trees can be quickly trained into an arch, as I'm doing with my pair of Kristins. I've pounded two straight ten-foot lengths of rebar into the ground to make each side, and then I've bent a twenty-foot length of rebar into a roughly-curving arch that I tied to each of the side stakes. Don't worry that the curve of the arch is only approximate. The width of growth of the weeping trees is likely to be a foot or even two across, and will quickly hide irregularities in the curve of the rebar itself.

 

Arch training is, typically, a late-Summer and early-Fall activity, because the new branches will have completed growing for the season, but will still be flexible enough to be repositioned. I gather weeping stems together around the rebar, and tie them in place—pointing farther up the arch—with twine or clothesline. Don't worry that the leaves are smooshed together and facing inward; they'll be shed in weeks. Next year's crop will face outward.

 

The tied-up stems will send out side branches readily. You could prune them back, stimulating still more side branches, and helping the arch thicken up. Or include them in the annual Fall retying. Or you could let a few grow naturally, to stream downward like tendrils of hair escaping from an upward "do." 

Quirks and special cases

None.

Downsides

None. Unlike Cornus florida, Cornus kousa is normally free from pests and diseases.

Variants

There are many! Putting aside the hybrids of Cornus kousa with Cornus florida, there are many scores of cultivars of Cornus kousa itself. One source lists over 120, another "just" 93. ('Kristin Lipka's Variegated Weeper' appeared in a collection solely of weeping cultivars of Cornus kousa.) The species is variable from seed; combine that talent with intentional crosses, spontaneous mutations, and generations of attention of fans and breeders, and it's no wonder there are new cultivars in each year's crop of catalogs.

 

Habits can be dwarf or weeping or both. Leaves can be variegated with white or yellow, in different patterns and degrees. Fall foliage color can be notable. Leaf shape and size can vary, as can that of the bracts that are the "petals" of the flowers. Bract color can be shades of cream and white, as well as pink deepening into rose. Cultivars can have both variegated foliage and rose-colored flowers. The foliage of the the variety angustata is evergreen, but only attractively so in Zone 8. There is even a cultivar whose fruits are yellow instead of the usual red; fittingly, it is called 'Xanthocarpa'.

 

Two forms are on my radar: The variegation of the foliage of 'Wolf Eyes' is stable and lasts all season; I'm training a pair to frame a large doorway. The foliage of 'Snowboy' is small but exceptionally bright with white variegation; this slow-growing cultivar scorches quickly unless it receives dappled shade.    

Availability

On-line and, occasionally, at retailers.

Propagation

By grafting.

Native habitat

Cornus kousa is native to Korea, but is seen in temperate-climate gardens world-wide. 'Kristin Lipka's Variegated Weeper' was a spontaneous mutation—known as a "sport"—that appeared in Pennsylvania. It was introduced in 2002.

 
 
FacebookTwitterRSS Feed

Stay in touch!

 

Sign up for twice-monthly eNews, plus notification of new posts:

 

* indicates required