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

'Tokyo Tower' Fringetree

I had delayed welcoming fringetree to my garden because the straight species is often a wide ornamental tree, not a shrub. But this Tokyo Tower cultivar is a godsend for any garden already dense with beauties: It’s a slender column in adolescence, and may never grow wider than four to six feet. 

 

Chionanthus retusus Tokyo Tower fingers close up 052718. 2 915

 

Even I have room for a pair, flanking one of the garden’s crosswalks. Free from concern over the trees' too-big maturity, I can enjoy their pristine spring flowers. Held in nodding panicles that emerge at the very tips of new growth, the blossoms can be profuse enough in established trees to bring a look of a sudden late-spring snowfall.  

 

Chionanthus retusus Tokyo Tower fingers close up 052718 915

 

Each of my pair of Chionanthus retusus ‘Tokyo Tower’ has a clump of Clematis recta 'Midnight Masquerade' nearby. Its spring foliage is burgundy, which highlights the bright green leaves of the fringe trees. 

 

Chionanthus retusus Tokyo Tower Clematis recta Midnight Masquerade overall 052718 915

 

The clematis’s pure-white flowers, still in bud here, are a bit later than those of the Towers. They are so plentiful that they will suggest that the snowfall that had blanketed the fringetree had then floated downward onto the purple foliage of the clematis.

 

 

 

Here's how to grow Chinese fringetree:

 

 

Latin Name

Chionanthus retusus 'Tokyo Tower'

Common Name

Tokyo Tower fringetree; columnar Chinese fringetree.

Family

Oleaceae, the Olive family.

What kind of plant is it?

Deciduous ornamental tree.

Hardiness

Zones 5b - 9.

Habit

Strikingly narrow and vertical, especially when young. With maturity, broadening only slightly, to the profile of a fat cigar. Even then, the habit of Tokyo Tower is in starting contrast to the broad-as-wide multi-trunked moundiness of a typical Chionanthus retusus.

Rate of Growth

Medium.

Size in ten years

Twelve to fifteen feet high and four to six feet wide. 

Texture

Narrow and short-branched when young, the tree is quite a skinny adolescent. With maturity, it increases in height and, modestly, in width—and, therefore, density.

Grown for

its habit: The straight species of Chionanthus retusus can range from large and tree-like to multi-trunked and shrubby, but is never as conspicuously narrow as Tokyo Tower. Whatever its habit, the straight species is likely to mature taller than Tokyo Tower, too.  

 

its white flowers: Pure white and narrow-petaled, the flowers are held in panicles that are numerous enough and fluffy enough to cover the tree in a snow-like display. To my nose, there is little fragrance, but it is reported as being delicious.

 

its light-brown exfoliating bark, which can become strikingly furrowed with age.  

 

its heat tolerance: Chionanthus retusus revels in months of the sweltering humid weather, day and night, that can typify summers from New York south.

Flowering season

Mid-spring: May into early June here in southern New England.

Color combinations

Its dark green foliage and white flowers can go with almost anything—but possibly just as neutral mixers. See "Partner plants," below, for suggestions on how plant partners can be more specifically engaging with fringetree's hues.

Partner plants

The distinctive habit (narrow, regular, and not too tall), small footprint, seasonal peaks (spring flowers, dark-green summer foliage, yellow fall foliage that drops to reveal interesting winter bark), and year-round visual integrity of Tokyo Tower make it a versatile garden presence.

 

Use as a clipped hedge or natural screen will likely be rarer than placement as a soloist or in a geometrically precise line or a group.  For screens or hedge, Chionanthus retusus needs as much sun as possible top to bottom to remain maximum uniform density, so companion plants on the sunny side should be low. Thinking of this species’ appreciation of full sun plus its requirement that drought-stress be avoided, companion plants that also appreciate these same conditions are likely to perform the best.  What about a fluffy “shin-high” ground cover of hay fern, Dennstaedtia punctilobula? Perhaps punctuated with clumps of any form of Rodgersia?

 

Thanks to its regular habit and intriguing bark, Tokyo Tower has sufficient structural and visual integrity to  plant specifically for a winter-priority context. Evergreen presence at ground level for the rich and even occasionally damp soil Chionanthus prefers I tricky, in that few evergreens (coniferous or broadleaved) tolerate plentiful soil moisture in any season, least of all in winter. I suggest one of the compact cultivars of inkberry, Ilex glabra, whose moisture tolerance is exceptional. Nordic (also known as Chamzin) is the most compact I know of.

 

If winter presence isn’t the priority, some herbaceous possibilities are available. For whichever side of the hedge or screen receives more shade, any number of hostas will be delighted with the good soil and reliable moisture. If the hedge does not run north/south, daylilies could carpet whichever side is sunnier: Their daily flowers track the sun as it moves from east to west, so if they were planted on the east side of Tokyo Tower, the flowers would be nosing into the knees of the Chionanthus by dusk. If the hedge or screen ran east to west, though, the south side would be Hemerocallis heaven from dawn to dusk.

 

Another spring-through-fall partner for the sunny side of a Tokyo Tower line-up isn’t affected by these directional nuances. On my bucket list for client projects is to front Tokyo Tower with thread-leaf Amsonia, whose feathery foliage and billowing habit would be in thrilling collaboration with the dark foliage and calm upward presence of the Chionanthus.

 

If you do have the opportunity of siting Tokyo Tower near a pond or stream, or at the margin of a rain garden, moisture-loving companion plants that partner with style, not just compatibility of habitat, include almost any fern (which provides lacy contrast to the Chionanthus foliage) and Petasites (which provides huge lotus-like foliage in contrast to the comparatively small Chionanthus leaves). 

 

These underplanting would also work well when Tokyo Tower is used individually. If the trees are spaced rhythmically in a mixed planting, there is more flexibility with the heights of the companion plants, because no single one of them is likely to be both high and wide enough to compromise the sun-loving growth of nearby Chionanthus.

 

Partners that are interacting coloristically with Tokyo Tower's narrow palette of solid-white flowers and solid-green foliage would be most engaging when they first nod carefully to that restricted range by having a prominent element of green or pure white in their displays. What about white-variegated hostas at the shady side? White peonies at the sunny side? White lilacs at the side? But then, bring on an uncompromisingly full-throated contrast.

 

The Midnight Masquerade clematis works so well because it "does" white so well, via its elegant flowers—but also displays them atop mounding matte-burgundy foliage. Similarly, there will be some form of iris in flower at the same time as Tokyo Tower whose petals combine pure white with indigo, orange, red, or pink. Similarly, the green fronds of ostrich ferns, Matteuccia struthiopteris, go toe-to-toe with the green Chionanthus foliage—but the fern's prominent fertile fronds are prominent vertical plumes of cinnamon.

Where to use it in your garden

Chionanthus retusus is versatile. Its habit is regular enough, and its height comparatively modest, that the tree could punctuate large swathes of low shrubbery, perennials, or grasses. Its heat tolerance means that it could be the full-sun pillars in the midst of a blazing, carpeting expanse.

 

A pair could flank a sunny doorway, or the beginning of a walkway; a quartet could mark an intersection.

 

Tokyo Tower's regular height, plant to plant, combine with its consistent cigar-like profile to make the tree suitable for use as a natural screen, particularly where coverage is needed only up to twelve to fifteen feet. This makes Tokyo Tower particularly valuable as a natural screen that doesn't cast as much shade as would be formed by other narrow trees, which might easily grow twenty feet high, or much higher. (Sunspire magnolia, for example, as as narrow, but matures to twenty-five feet. Slender Silhouette liquidambar is also as narrow—but can mature to fifty.) Tokyo Tower would also be a candidate for a clipped hedge. See the second "How to handle it" box, below.

 

The species' dislike of prolonged drought is balanced by its flexibility in growing near fresh water. You could even consider it for upper slopes of rain gardens, where its roots may occasionally find themselves in fully saturated soil for several hours or even a day..

Culture

Any soil and situation that ensures reasonable moisture retentiveness. Chionanthus retusus tolerates occasionally saturated soil, but is unhappy if drought-stressed. The species thrives in full sun throughout its range, but also tolerates a bit of shade. Flowering is more profuse in full sun.

How to handle it: The Basics

In Zones 7 and warmer, Chionanthus retusus might be planted in spring or fall; in Zone 6 and colder, plant only in spring. Remember that this tree doesn't like drought, so be attentive as it establishes.

 

In subsequent years, water deeply every week or two if your summer weather becomes dry and sizzling.

 

Trees that are intended to grow free-range don't need formative or maintenance pruning.

How to handle it: Another option—or two?

It's often the case that fastigiate forms of trees can mature as tall or even taller than their natural-habit forms. Tokyo Tower is striking in that it's both narrow and not as tall as the straight species, so is a natural possibility for informal screening of only modest height—below twenty feet, in other words—as well as for hedges whose mature heights would be maintained anywhere from six to twelve feet.

 

For screening, planting youngsters three feet apart is sufficient for them to grow together into a uniform and dense screen as they mature.

 

For hedges, you could take into account how narrow, even spindly, young Tokyo Towers are: Even five and six-foot youngsters might not be wider than twelve inches. If you needed a hedge that might never grow wider than a foot, Toyko Tower could be the candidate. Plant young Towers as closely together as you can find and afford: a foot apart would be fantastic, but eighteen inches or two feet will also, in time, fill in.

 

To keep your hedge narrow, you'll need to prune starting the second year after planting. Do this right after flowering. Not ony does this remove the spent flower clusters, it also stimulates growth of side branches, which increases the density both of the current season's growth as well the flower clusters formed next season. After some years of growth, you may need to prune more severely to re-achieve the ultimate narrowness you'd like to maintain. Go right ahead.

Quirks and special cases

Flowers of Chionanthus retusus form at the tips of new growth and, hence, are more directly showy than those of our native Chionanthus virginicus. Its flowers form at the tips of last year's growth even as the current year's vegetative growth is emerging but are so voluminous that they aren't at all hidden. 

Downsides

Chionanthus retusus is much less hardy than our native Chionanthus virginicus, which is reported as thriving throughout Zone 4 and even into 3b, the "warmer" portion of Zone 3. Gardeners in Minnesota or Quebec will need to celebrate Chionanthus virginicus—and to visit Chionanthus retusus on trips south.

 

In certain settings, the tree's tolerance of heat and absolutely full sun might also subject them to drought stress. If your soil isn't moisture retentive, Chionanthus retusus would need regular watering. It would be better to plant a tree that appreciates sharp drainage and drought.

Variants

Even as late as 2015, this reputable online database didn't list a single cultivar of Chionanthus retusus. They are entering North American commerce slowly, sometimes (as with Tokyo Tower) thanks to importation from Asia. Part of the challenge is reliable and reasonably-quick propagation, which isn't at hand yet either by seed or vegetatively. (See Propagation, below.)

 

Arnold's Pride is a female selection from the Arnold Arboretum, reportedly with abundant flowers and blue fruits; the original is thriving there still. Daruma, also female, is significantly compact compared with the straight species: to ten feet high and wide, not twenty to forty.

 

In addition, there is variance within the species itself, with both a more upright, trunked, tree-like form, and a broader-than-wide shrubby form. This latter has been listed as China Snow; its flowering and foliage are reported as being superior to the upright forms of the straight species.

 

Cultivars of Chionanthus virginicus are slowly becoming available. All the cultivars tout heavy flowering, so the differences are in sex—male cultivars produce no fruit, which might be good if trees are sited near pavement, but isn't great in terms of forage for wildlife—habit, and foliage. Emerald Knight is a male with a more upright habit. Prodigy is a female with a rounded habit and noticeably darker-green foliage. Spring Fleecing is also male, but with narrower foliage. White Knight is a male that flowers heavily even when young.

Availability

On-line and at specialty nurseries.

Propagation

The species can be propagated both by seed—whose dormancy is multi-stage, and requires patience to break—and cutting. Tokyo Tower will not come true from seed, though, so much be propagated by cutting.

Native habitat

Chionanthus retusus is broadly native to eastern Asia: China, Korea, Japan, and Taiwan. Tokyo Tower originated in Japan, and was brought to the United States by Harold Neubauer of Hidden Hollow Nursery in Tennessee.

 
 
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