A Gardening Journal

American Elderberry

Out at the streetfront of my property, large plants grow more-or-less on their own. Here, the native elderberry remains a monster year after year, a striking contrast to the weak and, eventually, failing performance of the many European ones I tried.

 

Sambucus canadensis Maxima overall 061816 640

 

This is the cultivar, Sambucus canadensis "Maxima', and it's even more vigorous than the straight species. The flowerheads can be eighteen inches across, although, as you can see here, on bushes that receive little regular pruning, they are the normal six inches or so. See the second "How to handle it" box, below, for pruning options.

 

The size of the florets doesn't differ between 'Maxima' and the species; the larger heads of 'Maxima' simply have so many more florets. Individually, the creamy white blooms are a modest delight; the projecting yellow stamens seem to welcome the season with open arms.

 

Sambucus canadensis Maxima cluster closeup fingers 061816 640 

 

Although this shrub is probably bearing thousands of flowers, few of them will mature to fruits even though, as a native species, the preferred pollinators are likely to be at work. Fruiting is enhanced when multiple shrubs are present, especially if they are different cultivars. See "Variants," below, for cultivars that have been selected specifically for their fruiting capability.

 

Sambucus canadensis Maxima cluster closeup fingers 061816 closer 640

 

Even the straight species of Sambucus canadensis is vigorously stoloniferous, so this isn't a plant for compact gardens. It usually needs control even in larger settings, and definitely in my garden, where I'm always puzzling how to squeeze in another few dozen of the lastest must-haves.

 

But because the species is stoloniferous, perhaps I could plant a second cultivar right alongside this 'Maxima', and then let them grow together. The overall footprint might not change but—as if by magic—the colony would now be setting a good crop of fruit. Especially if I were more diligent with any of one of the pruning options, I'd be controlling the colony's size more successfully. So I could introduce that second cultivar without sacrificing more room. I'd be able to have my cake—I mean, my elderberry jam—and eat it, too.

 

 

Here's how to grow American elderberry:

 

 

Latin Name

Sambucus canadensis 'Maxima'  

Common Name

American elderberry, common elderberry.

Family

Adoxaceae, the Viburnum family.

What kind of plant is it?

Deciduous shrub in Zones 3 to 8; evergreen in frost-free weather in Zones 9 to 11.

Hardiness

Zones 3b to 11.

Habit

Upright and broad, but also stoloniferous, forming broad colonies unless controlled. Despite the stolons, this species is prone to bare knees, not just bare ankles. See the second "How to handle it" box, below.

Rate of Growth

Fast.

Size in ten years

Grow Sambucus canadensis without any pruning or control only when naturalizing the species in roomy settings. There it can grow ten to twelve feet high and wide. The shrub can be pruned to control height and width; see the second "How to handle it" box, below.

Texture

Thanks to the pinnate foliage, the texture is full but lacy. The doily-like flowerheads enhance this.

Grown for

its larger-than-usual flower heads: 'Maxima' is the only cultivar of Sambucus canadensis selected for its flowerheads, which can be dramatically larger than those of the straight species: to eighteen inches across instead of six to ten.

 

its later-than-the-European species' flowers: Sambucus nigra and S. racemosa are reported to flower a month earlier than S. canadensis. The European species don't tolerate the heat and sporadic drought typical of all but northerly, ocean-side, or high-elevation gardens in eastern North America, so I don't have direct confirmation of this. In general, no garden needs one more shrub that flowers in May—and, conversely, one fewer spots for anything that flowers in late June. Sambucus canadensis merits inclusion even in gardens that are able to lavish themselves on S. nigra and S. racemosa

 

its durability: Unlike the disappointingly ephemeral European elderberries, Sambucus nigra and S. racemosa, Sambucus canadensis  can be with you decade to decade. I planted my 'Maxima' in 2002, and it has maintained its vigor in seeming defiance of both my neglect—it has never been watered—and a radical pruning every few years. See the second "How to handle it" box for pruning strategies that are more regular as well as thoughtful.

 

its low appeal to browsers: All parts of the plant— from roots and stems to foliage and seeds—contain a chemical that the body metabolizes to form cyanide. This is probably why the foliage is rarely browsed by deer; alas it doesn't deter Japanese beetles.

 

its fruits' great appeal to birds as well as humans: Unless your goal is to provide food for birds, you'll need to net your elderberry if you want to harvest the crop. Reportedly, a flock of birds can strip all the fruit from a given shrub in less than an hour. While the berries (and flowers) aren't toxic to birds when eaten raw, they are edible by humans only when cooked or fermented. 

 

its flowers' appeal to pollinators as well as humans: Sambucus canadensis flowers are visited by butterflies, bees, and moths. The flowers can be picked and processed for elderberry syrup, which flavors elderberry wine. Entire flowerheads can be dipped in batter and fried.

Flowering season

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

Color combinations

With its mid-green leaves and white-petaled flowers, Sambucus canadensis can mix with any color from pastel to saturated, cool to hot, dark to light, and neutral to assertive. But, although white and green do go with every other color, this is more true in concept than reality. It's more practical to look through the other end of the telescope: They don't clash with anything.

 

I welcome white and green to my red garden as much as my pink borders, but mostly from relief at being able to bring these neutral filler colors into schemes that are otherwise challenging due to their paucity of on-target foliage, not just flowers. For combinations with Sambucus canadensis that are active, not passive, look to the flowers' anthers, which are tipped in yellow pollen. In addition to yellow, those anthers will pair well with blue, burgundy, and (in larger dollops than the tiny Sambucus petals) white. If the partner's coloring also includes yellow, then a direct linkage is made, making the addition of red, purple, pink, and orange also possible.

 

See "Plant partners," below, for both categories of interaction.

Partner plants

The flower clusters of Sambucus canadensis are so large, bright, numerous, and densely arrayed that the shrub would be difficult to mix with other flowering plants without the look veering into overload. To show up, such other blooms would need to be of strikingly different size, array, or color, and on plants of sufficient size that their flowers are displayed in the same general field of view as those of the elderberry. June is such a bountiful season for flowering that, despite all of these caveats, there are plenty of options, including large-flowered forms of roses and clematis, as well as taller forms of mullein. As long as there's some detail of yellow in those flowers, the link to the yellow of the elderberry anthers is made; whatever other colors the partner plant might emphasize will now fit in comfortably.

 

Even when successful, such flower-to-flower combinations can seem conceptually limited. Plants have many other characteristics, such as foliage, form, fruit, habit, and texture, while the overall array of plants in a garden brings in still more options of geometry, scale, and repetition. It's a disservice to the education of the gardening public to create even the inference that the horizon of anyone's horticultural vision should extend no further than flowers.

 

Plus, it's easier as well as more thought-provoking to create a context for this elderberry that focuses elsewhere than flowers: If you pair with other plants also in flower in June, you're only increasing the area of your garden that will not be in flower the rest of the growing season. Also, plants whose performance is based in part or in whole on non-flowering qualities are likely to remain visually appealing for months at a time, or even year-round.

 

Here's a starter list of plants for which a nearby Sambucus canadensis in full flower can be just some seasonal fireworks, not the entire show. Some have white-variegated foliage, others have foliage that's yellow or burgundy: Acer shirasawanum 'Aureum', Aralia elata 'Aureovariegata', Catalpa x erubescens 'Purpurea', Chamaecyparis obtusa 'Fernspray Gold', Cornus alba 'Aurea', Cotinus coggygria 'Velvet Cloak', Cryptomeria japonica 'Sekkan Sugi', Miscanthus x giganteus 'Golden Tower', Orixa japonica 'Variegata', and Ulmus glabra 'Aurea'.

 

Remember, also, that a backing of dark and dense evergreens enhances anything to their front. Could your elderberry be in front of Ilex 'Nellie R. Stevens' or a hedge of Taxus cuspidata?

 

Surprisingly, when pairing one plant that has a limited but dramatic flowering season with other plants also with limited but dramatic flowering seasons but at other times of the year, then there's no problem with a seeming lack of imagination of partnering flowers with still more flowers. On the contrary, one's strategy and vision will both seem to be sharp. Plus, when one plant is in bloom it helps cover for all the other flowering plants nearby that are not. In the second "How to handle it" box, below, I mention an obscure but exciting early-season ephemeral, Ranunculus 'Brazen Hussy'. Galanthus could be another possibility, especially in that it can provide plenty of interest in February and March. Forms of Group C Clematis bring exuberant flowers in August or September; handily, they too prefer rich moist soil, and would be cut back in late Winter along with the host Sambucus. Look first among the many cultivars of Clematis viticella.

Where to use it in your garden

You'll need to control the shrub's lateral spread diligently if you intend to use Sambucus canadensis near detailed smaller-scale plantings; they'll be swallowed up quickly otherwise. It's easier to site in large-scale settings and amid trees (for whom the Sambucus will be just so much splashing about their shins and ankles), with a sweep of low colonizing groundcovers (think vinca, pachysandra, and xanthorrhiza) that don't care that Sambucus stems are shooting up amid them.

 

It's tempting to control the underground spread of Sambucus canadensis by siting this shrub where its planting area is bounded by paving or walls. But such settings are rarely moist, because it's usually best practice for water to drain away from masonry. Plus, unless you control the overall size of the shrub, it could grow so densely that, in effect, it dries out its planting area and declines from drought stress. Instead, control the size of your colony by human intervention and, if you have the opportunity, choose a site near ground so wet the shrub can't spread farther in that direction. Sambucus canadensis is not a shrub for marshes, but could be terrific along an uphill shore of freshwater streams and ponds—or at the rim of a rain garden's retention pond or swale.

 

Afternoon shade provides partial compensation for ground with lower than ideal water content, so consider siting this shrub to the east or north of shade trees, such that it receives full sun only in the morning.

 

If your setting is truly expansive, Sambucus canadensis can function as a large-scale groundcover provided that you keep its preference for soil moisture in mind. Groundcovers are effective when the plant in question can provide dense coverage over the full extent of the desired area. But the denser the growth, the greater the ambient soil moisture needed to sustain it. I dream of a very large stretch of alluvial soil bordering fresh water, where trees such as Alnus, Platanus, and Taxodium (this latter in its upright form, not the weeping or dwarf forms I've profiled) would be delighted to grow there; Sambucus canadensis would be pleased to ramble ever-onward through their grove.

Culture

Full sun to shady woods; welcomes clay (and, therefore, often waterlogged) soil, as well as soil of any character in low spots that pool after storms or during the Winter. Sambucus canadensis is strikingly more tolerant than either S. nigra or racemosa of terrain and soil that provides only normal levels of moisture, and can still look presentable during the hot and rainless days typical of eastern North America in August. That said, S. canadensis is not a shrub for sites that experience both hot afternoon sun and prolonged drought regularly. Here is a detailed look at all facets of culture of this species and a number of its cultivars, as selected and handled as a fruit crop in Missouri. The pruning options on pages 72 - 74 are as effective in tidying this species' growth and increasing the size of its flowerheads for the display garden as in facilitating the harvest of its fruit in production fields.

How to handle it: The Basics

Plant in Spring or Fall, ensuring enough water for establishment. If there is sufficient soil moisture, shrubs thrive year after year on their own. Growth usually becomes extensive enough that you'll want to consider some pruning. See below for options.

How to handle it: Another option—or two?

Sambucus canadensis usually needs pruning just as a matter of self-defence lest the shrub colonize too much of your garden. To keep the game interesting—and to control an older shrub's tendency toward billowing top-heaviness that never quite hides its bare shins—here are more thoughtful interventions:

 

1. If a complete rethink is appealing, go for a massacre, regardless of the season, and cut all branches down to the ground. This can be a big job, involving some awkward lopping and hand-sawing while on your knees, so get it done when the bug has really bitten.

 

At the next growing season, the shrub will resprout from any stubs you leave behind, and will also send up shoots from underground. If you've pruned in mid-Summer, those shoots won't amount to much that season, but will flower the next. There isn't anything to gain by pruning right after flowering, which just deprives birds (or you) of the fruit crop to come. Plus, Sambucus canadensis is extremely hardy, so you don't need to worry if young growth won't have hardened enough to survive imminent Winter. Want to prune even though it's early Summer, mid-September, early December, or late March? Go right ahead. 

 

If you prune in Winter or early Spring, the shoots will begin to appear just weeks after the deed, and should flower that same season. If you could keep this early-season slaying as an annual or biennial ritual, your Sambucus canadensis will perform like its unique perennial cousin, Sambucus ebulus. But why not just grow the latter?

 

If you do decide on this to-the-ground handling, keep track of the timing and size of the flower clusters. The shoots will be more or less the same height, and flower nearly simultaneously, so the intensity of the display will be heightened. Is the show later than normal? That could be a plus. Are the flowerheads larger than normal? A second plus.

 

A third plus: You could include a partner plant that would appreciate the sun while the Sambucus is temporarily just stubs or six-inch shoots: a moisture- and sun-loving Spring what's-it that's gone by the end of May. Yours would be an impressively dense garden for the only spot for a huge patch of, say, 'Brazen Hussy' ranunculus to be right where you had no choice but to plant Sambucus canadensis. To be at the mercy of such garden imperatives is always cause for joy. See "Plant partners," above," for another option. 

 

 

2. With a plant this vigorous, even half-way measures can work. Cut all branches back by half in late Winter. This tactic controls overall size but only modestly: The new side shoots are likely to grow several feet before flowering, but at least there will not be those ten-to-twelve footers arching overhead. Removing the top portion of the branches stimulates the production of side shoots (as well as new shoots from the ground). Those side shoots should flower that same season. Because older branches that would now be cut back might have ramified repeatedly, you may not increase the overall number of flower clusters by such pruning, but they will be displayed atop a somewhat more compact and dense mass of growth. (The effect is the same as is achieved by pinching the ends of the stems of chrysanthemums in mid-Spring.) The downside is a more congested and "pruned by the landscape crew" look to the bare branches in Winter.

 

3. Most subtle of all is cutting only the largest branches to the ground in early Spring. You'll probably need to do some of this while on your knees under the overhang of the shrub's canopy, so you won't be able to easily judge which stems are the oldest by their height. Not to worry. Your quarry will also be the thickest as well as branchiest stems, so you'll have no difficulty distinguishing them at ground level from the slender youths you'll want to retain.

 

Thinning the shrub instead of massacring it limits overall size while avoiding the enormous (if temporary) bare patch resulting from the wall-to-wall slaying of option 1. It also avoids the less-than-graceful hacking of option 2. It also yields a somewhat more orderly look to the bare branches in Winter, which is always this species' weak season.

 

The young branches you leave behind will flower in June. Since removal of the largest branches (which are also the branchiest and tallest and, hence, cast the most shade on lower growth) allows more sun to reach shoots emerging from the ground, the shoots will be all the more vigorous. In a year or two, some of the branches that you didn't cut off this season will have become large enough to merit attention from you and your loppers, continuing the cycle of ongoing renewal that keeps the shrub in a bushy and floriferous steady state that never looks less than graceful year-round.  

Quirks and special cases

Sambucus canadensis has an unusually broad range of hardiness, and thrives from near-Arctic climates of Quebec to the frost-free tropics of south Florida, where it is evergreen as well as ever-blooming.

Downsides

If sited within a garden, not naturalized in a large-scale setting, Sambucus canadensis will need regular pruning to control its spread. Fortunately, its floral display is normally improved by the pruning, as is the look of the bare branches in Winter. See the second "How to handle it" box, above.

Variants

The many elderberries with exciting variegated or purple foliage are cultivars of two European elder species, Sambucus nigra or S. racemosa and, in my experience, don't tolerate the heat or drought typical of Summers in eastern North America. Try them if you can provide consistently moist soil Spring to Fall, as well as dappled shade or shade from mid-day onward. If you're gardening in colder climates—Zones 4 and 5—your Summers may be cool enough for these shrubs to thrive in full sun. Lucky you!

 

The only European cultivar I have had luck with is S. nigra 'Laciniata,' and only when the shrubs are sited in part shade, enjoy bottomless rich soil, and the gardens experience the cool-all-Summer weather of seaside real estate. Someday I hope to be able to tour these geek-worthy gardens in coastal Maine and Montreal, where a fetish for S. nigra and S. racemosa could be indulged to great effect. There could be a dozen different forms to review—if they'd get them planted.

 

There are a few forms of Sambucus canadensis that are notably more ornamental than the species. Flowerheads of 'Maxima' can be larger—to 18 inches across—and the cultivar's overall vigor is enhanced. This is a determinedly stoloniferous shrub! Foliage of 'Aurea' is soft gold, and its berries are red. Foliage of 'Laciniata' is as feathery as that of a Japanese maple or the 'Laciniata' cultivar of Sambucus nigra; growth is slower than that of S. canadensis, and overall height is less. Both S. canadensis 'Aurea' and 'Laciniata' are on my wishlist.

 

Other Sambucus canadensis cultivars—'Adams', 'Johns', 'Nova', and 'York'—are grown for their fruit, which might ripen later or earlier, or is more or less profuse. Their pinnate foliage is typical of the straight species.

 

Sambucus canadensis is usually easy to distinguish from both S. nigra and S. racemosa. In the cool-Summer climates where it thrives, S. nigra can be much larger—potentially to twenty and thirty feet—and with the multi-trunked habit of a tree. It also flowers several weeks earlier. Neither it nor S. racemosa are known to sucker with the persistence and vigor of S. canadensis. The fruits of S. racemosa are red, not black; it, too, requires a cool-Summer climate.

Availability

Online. 

Propagation

Easy! Sambucus canadensis is a shallow-rooted suckering shrub, and the thick rhizomatous root connecting an out-of-bounds shoot back to the mothership can be separated in Fall or Spring. Dig up the section without worrying about keeping soil attached; bare-root sections transplant readily after their attached shoots have shed their leaves in Fall and before new foliage emerges in Spring.

 

Both semi-hardwood and hardwood cuttings root well, too.  

Native habitat

Sambucus canadensis is broadly native to North America, from Nova Scotia to southern Ontario, and west to the Mississippi valley bordered by Minnesota and Wisconsin, and then south from southeastern Texas through all of Florida. If you are gardening east of the Mississippi, this species of Sambucus is likely to be part of your neighborhood's native flora. 

 
 
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