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

Orange-twigged Linden

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Young growth of orange-twigged linden: The colder the Winter, the brighter its bark.  Incredibly, being flaming orange isn't colorful enough; the buds of the Spring leaves are hot pink.

 

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Only the new growth is colorful, so training this linden as a hedge, standard—or, as here, espalier—keeps it small enough to make two or three annual cuts convenient.  The twigs are always thickest along the top edge of the espalier, creating a fiery line that lasts right until the new leaves emerge in Spring.

 

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The regular pruning creates a virtuous circle.  The more the espalier is pruned, the more compact the espalier stays, which makes even more pruning all the easier, and which also ensures that even more new twigs are created.

 

 

 

Here's how to grow 'Winter Orange', the most colorful linden:

 

Latin Name

Tilia cordata 'Winter Orange'

Common Name

Orange-twigged linden

Family

Tiliaceae, the Linden family. 

What kind of plant is it?

Deciduous tree.

Hardiness

Zones 3 - 7

Habit

Broadly upright.  Usually available only as small starter plants, and therefore grows branched to the ground unless limbed up.

Rate of Growth

Fast.

Size in ten years

Fifteen to twenty feet tall and wide; ultimately taller than wide, to sixty feet and more.  Best not grown free-range: the Winter twigs are much more prominent when the tree is grown as a hedge, pollard, or espalier.  So, the ultimate height isn't normally achieved.

Texture

In leaf, full but not heavy.  Out of leaf—"in twig," in other words—'Winter Orange is a tracery of thicker branches and bright but slender twigs.

Grown for

the bright coloring of its first-year twigs in cold weather:  The bark is a bright copper-orange that can intensify to lobster; the leaf buds are a shocking, gleeful, strident pink. 

 

its ease of training:  Young linden branches are unusually flexible, so the trees have long been favorites for pleaching and espaliering, which always involve tying young branches to a training frame, or weaving them amid older branches that were aligned years before.  New growth emerges quickly from pruned branches, so the trees also make good hedges.  See "How to handle it: Another option—or two!"

 

its white flowers:  They appear in Summer and, although they aren't very showy, are sweetly fragrant.  Bees adore them; linden makes a distinctive honey.  Lindens that are pruned regularly flower only sparsely.

 

its hardiness:  Tilia cordata is a tree for cold climates and, as long as it's growing in decent soil and isn't drought-stressed, can be planted throughout the northern United States.  (Tilia americana is as hardy, but is also much more heat-tolerant; it's the linden of choice for the Deep South and even Florida.)

Flowering season

Mid-Summer. 

Color combinations

'Winter Orange' has no orange about it in warm weather, when the tree's leaves are green and its bark is boring.  Only in cold weather do you have the opportunity to coordinate with neighboring horticulture the showy twigs and their raucous (but only at close-range) pink buds .  See the orange-friendly suggestions for Alnus incana 'Aurea', whose Winter twigs are also orange and whose catkins, which are showy in Fall and much of the Winter, are also pink.  As with the alder, backing 'Winter Orange' with evergreens is the sure-fire way to highlight the bright twigs.  See 'Plant Partners' below.   

Partner plants

Ilex opaca 'Winter Sun' can provide an evergreen backdrop of whatever height is needed to showcase the twigs of 'Winter Orange'—and also sports berries that are an orange-friendly apricot instead of the usual red or yellow.

 

Because 'Winter Orange' is at its brightest when pruned to relatively compact and low-to-the-ground forms such as espaliers, pleaches, and hedges, you could consider underplanting it with cohorts that are orange-friendly in the Winter.  Their display will be close enough to new twigs of the pruned linden for the pairing to be strong.  The tree drops its Fall foliage cleanly and quickly, so underplantings get all Winter sun, such as it is.  The linden's orange twig color is held right through the chilly weeks of early Spring, so early bulbs are possible, too, not just true Winter flowerers.  But orange is actually a bit rare in Winter-flowering species.  The yellows of early daffodils or Winter aconite would be as jarring near the linden's orange twigs and pink leaf-buds as the blues of scilla or crocuses.  Snowdrops or wood anemones are neutral white, but not very inspired.  Helleborus orientalis 'Apricot Blush' is a possibility, but it would be completely out of my budget as the exclusive underplanting for the hundred-plus feet of my 'Winter Orange' espalier.

 

Yes, there are loads of early tulips that are orange, but I worry that their foliage needs more and longer sun in Spring than would be possible under the swiftly-burgeoning leafiness of a well-pruned linden, which branches out with relentless joy as soon as warm weather is at hand.

 

But there's a crocus to consider.  Crocus olivieri balansae 'Zwanenburg' is the rare one with flowers that are a true orange, not just a deep butter yellow.  I have avoided Crocus species and hybrids because the squirrels love them, but the chance to underplant 'Winter Orange' and 'Zwanenburg' tempts me.  The solution to prevent squirrel attack is to cover the planted area with chicken wire, or, ideally, a heavier and longer-lasting wire mesh with smaller openings.  The bulbs' foliage and blooms extend themselves up through the mesh, which can be easily hidden by a light cover of mulch.  And crocuses complete their Spring cycle much earlier than tulips, too.

 

I doubt that epimediums bloom early enough to catch even the last weeks of the 'Winter Orange' twig display, but if they did, orange-flowered E. x warleyense would be the one to plant.  This Spring, I'll confirm if this pairing is possible, at least here in warm Zone 6; I have warleyense planted in the Red Garden.

 

Fuller-size colleagues whose Winter performance is orange include Hamamelis x intermedia 'Jelena' and Alnus incana 'Aurea'.  These wouldn't be underplantings, of course, but they could be "adjacents." 

Where to use it in your garden

'Winter Orange' is best—i.e., the orangest—when it receives regular pruning.  And it can only receive that pruning when that maintenance is part of a larger strategy to keep the tree trained to an accessible size.  Few people will have the equipment or the confidence to prune lindens that are twenty, thirty, or forty feet tall; leave that to municipal crews in countless cities in Europe.  Further, the tree needs at least two "cuts" annually, so needs to be planted with enough easy clearance on all sides for you and your ladder or pruning platform.  

 

This regular training—and the fast growth of new twigs that it encourages—is only practical when the intended shapes are as simple as possible.  Pruned lindens, therefore, inevitably assume architectural and even structural forms, as hedges, standards, espaliers, or pleaches.  See "How to handle it: Another option—or two!" below for the details. 

 

A linden espalier needs to be free-standing, not against a building.  The new growth becomes several feet long and would bump into the building in weeks after a cut, and lindens are so hardy that they don't need the protection of a building anyway.  (Instead, use that building's wall to espalier a species that's just a bit tender.)  A free-standing espalier is the perfect choice to separate adjacent areas of pavement, such as a walkway or terrace that needs to abut a parking area or driveway, because you have automatic access to both faces of it.  Or to back a large bed that has grass or paving on the far side; in this case be sure to leave a wide access pathway between the plants at the back of the bed and the espalier. 

 

A standard of 'Winter Orange' eventually develops a thick trunk.  They are thrilling in pairs marching out into a meadow, or along either side of a walkway.  They are too tree-like to be part of mixed plantings, as you might do with species such as willow, alder, or elm, whose trunks thicken-up more slowly.  

 

Overhead pleaching is just giving nearby pairs of linden standards permission to extend a few of their limbs into one-another's canopies.  Their use is the same as with standards, whose canopies are kept separate. 

Culture

Any decent soil with good drainage year-round.  Lindens are not interested in soil that's dry, but neither are they interested in soil that's unusually heavy or prone to slow drainage.  (I, alas, have proven this latter advice in my own garden.)  Full sun is best.

How to handle it: The Basics

Lindens transplant easily, but you're unlikely to find large specimens of 'Winter Orange', so you'll normally be planting small container stock. 

 

For a linden hedge, plant in Spring, every two feet, and let the young trees grow on their own the rest of the season.  The next Spring, cut the branches back by half, and as soon as they've branched out more than a foot, cut that new growth back by half, as well.  You may want or need to prune a third time, too, in early or even mid-September.  See how late in the Fall you can prune while still leaving enough time for the hedge to produce a good show of new twigs; the later this last cut, the shorter the resultant twigs will be, and the tidier the hedge will look all Winter.  Such late-season twigs are still fully hardy; there's none of the worry about hardening off new growth that you would have when pruning, say, holly.  

 

As with all hedges, work to keep the top of the hedge much narrower than the bottom, so that the bottom gets all possible sun and grows as thickly as possible.  In reality, it's easier to keep the top of the hedge narrower than to "widen-up" the bottom, so concentrate on being ruthless in pruning back the top, and allow yourself to be less of a martinet in restraining the bottom growth.

How to handle it: Another option—or two?

Linden espaliers are easy.  Plant six to twelve feet apart; lindens put out long and flexible branches, and there will be no trouble developing growth that fills in fully.

 

Let the young plants grow two or three years, by which time they'll be bushy enough and tall enough to start into training.  Erect a simple pipe-frame as you would for a chain-link fence, just leaving out the chain-link.  Attach rungs of galvanized fence-wire every two feet, making them taut with a turnbuckle at either end.  Height is easy with linden espaliers; plan that the espalier is at least eight feet tall; ten is even better.  

 

To begin training the young and bushy trees, first bend down any branches already near the wires and secure them loosely in place with thick cord that won't cut into the bark; I use clothesline.  Cut off any branches that project outward so far they don't bend into the plane of the wires easily.  You'll see linden espaliers all over Europe when the branches are bent right to the rungs, and the overall growth is in rungs, too, with a gap between the growth of one rung and that of its neighbors.  In my experience, the hotter weather of a North American Summer produces such long growth—three or four feet wouldn't be unusual—that you'd need to prune the espalier weekly to keep to such strict form.  I recommend, instead, that you tie the branches to the wire rungs informally, i.e., diagonally, fanning each tree out so its growth meets and then interweaves with that of its neighbors.  After some of the initial "fanning-in", you can train a lot of subsequent growth simply, by weaving it through growth that's already tied in.

 

Every Spring, check over the entire espalier to retie any cord that has become too tight, or remove any ties that are now not needed because the branch in question has thickened and stiffened in the orientation you need.

 

Eventually, you'll have enough tied-in and weaved-in branches.  Then you can concentrate just on pruning the lateral growth from all of them, to keep the espalier narrow.  Prune as with the hedge, above.

 

Linden standards and pleaches are the most informal training of all.  Let the young tree grow on its own until its top is at least eight feet tall.  That height will be the bottom of the canopy of the standard you'll be creating.  Pinch the tips of new growth above that height, and remove the limbs below that height so you begin forming a clear trunk.  

 

Linden standards are often trained with multiple heads instead of just one.  All this means is that you don't cut some of the new growth all the way back to a stub each Spring.  Don't let these limbs develop vertically, otherwise you'll have to be reaching higher and higher for your pruning.  Instead, be thorough in pruning vertical new growth, and more relaxed about pruning horizontal new growth, at least until the canopy is as wide as you need.  In a few years, your linden standard will have a fairly flat canopy of thick branches from which countless new twigs will spring.  As Rosemary Verey did so masterfully in her own garden, plant linden standards where you can enjoy the view of these new twigs from the second story of your house.  They are always most colorful when seen from above.

 

To pleach linden standards, let horizontal growth from one tree lengthen enough for you to weave it into its neighbor.  You can tie branches from one tree to the next to help these pairings get started.  Over time, they may even become grafted together.  Prune off vertical growth, as for a hedge, letting horizontal growth proceed until the canopy is as wide as you need.

 

In pleaches and standards, leave gaps in the canopy of major limbs big enough for you to stand tall through them to do your pruning.  This is more comfortable than doing all the pruning from below. 

Quirks and special cases

Bees are so wild about linden flowers that they can get a little woozy.  Be careful when walking beneath lindens in bloom, especially if you're in bare feet.  You wouldn't want to step on a besotted bee, or, worse, get stung by it.

 

Bees on the ground beneath Tilia tomentosa may be more than besotted.  The tree's nectar contains a sugar, mannose, that some species of bees can't digest, and for whom the sugar is toxic.  These bees aren't merely drunk; they're comatose.

Downsides

Lindens can be infested with aphids, and Japanese beetles enjoy the foliage.  Healthy individuals are more resistant.  Eleven trees form my espalier of 'Winter Orange'; a dozen of T. platyphyllos form another.  None of either group of trees has ever been afflicted.  Tilia x euchlora or T. tomentosa are the trees to plant if aphids torment lindens where you garden; they don't have the colorful twigs of 'Winter Orange', but are equally easy to form into espaliers and hedges.

Variants

Tilia cordata has been widely planted in Europe for centuries—and still is—and many cultivars and hybrids have become available.   Many of the green-leaved cultivars have only small variations in branching, overall dimension, and general toughness, which are, nonetheless, important considerations when choosing lindens for street trees, especially in climates with heavy snow- and ice-load.  'Corinthian', 'Greenspire', and 'Rancho' are three of the most widely-available. 

 

More ornamental forms can have habits that are unusually narrow but full-height, dense and globose, sort of weeping, or shrubby; leaf color that can start out yellow in the Spring or turn yellow the Fall; or Winter twigs that are yellow or, as with 'Winter Orange', orange.  Alas, there are no purple-leaved or variegated forms.  'Handsworth' is the cultivar whose young twigs are yellow in Winter; it's on my wish-list, and I'll grow it as a coppiced shrub to maximize their display. 

 

The compact forms are terrific when grafted atop the trunk of the straight species to make a standard.  I have a pair of 'Summer Sprite' standards that I'll profile this year.  

Availability

On-line.

Propagation

Grafting.

Native habitat

Tilia cordata is native to Europe and Russia.  'Winter Orange' originated in the Netherlands. 






 

 

 

 

 

 

 

 

 
 
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