A Gardening Journal

The Best Season Ever: Farge's Cobra Lily

Arisaema fargesii flower front 062115 640.JPG

 

"Cobra lily." Those two words pack so much contradiction: A poisonous snake vs. a gorgeous flower. Aggression that's fatal vs. wouldn't-hurt-a-fly beauty. Sudden messy combat vs. stately and welcoming display. 

 

The perennial that bears the extraordinary flowers below isn't a lily at all, let alone some sort of fastidiously-striped snake. Rather, Arisaema fargesii is a star of a dappled-shade garden and, as striking as it is, the striped hooded flower spike is the least of the show.

 

Emerging late in Spring, the mysteriously covered structure—the spathe—demands to be explored. What's inside is not a spike of flowers in the traditional sense of petals and pollen, or butterflies and bees alighting. Instead, a spadix: a waxy rigid finger-like structure. 

 

Arisaema fargesii flower interior 062115 640 

 

If this plant is male, apetalous and tightly-packed male flowers will release pollen; the spadix will become fuzzy with it. (See a pollen-bearing calla flower here.) If the plant is female, no pollen is produced, and the spadix's look only changes when (and if) pollination occurs. (See "Quirks," below: Arisaema is infamous in how it handles the sexes.)

 

The vertical burgundy stripes of the spathe are wider at either flaring side, creating the impression of large comical ears at the side of what, from the front, looks more like a snake's head. 

 

Arisaema fargesii back of the flower 062115 640

 

As Spring eases into Summer, these startling flowers are overwhelmed by the foliage. The central leaflet always points down, while the two smaller ones point outward to either side: again, the comical big-ears vibe.

 

Arisaema fargesii leaf with flower 062115 640

  

Just weeks later, the leaves have gained their impressive full size—up to thirty inches across—and the striped floral structure is completely hidden.

 

Arisaema fargesii Filipendula ulmaria Variegata overall 072015 640

 

 

Here's how to grow this enormous perennial:

 

Latin Name

Arisaema fargesii

Common Name

Farge's cobra lily

Family

Araceae, the jack-in-the-pulpit family.

What kind of plant is it?

Hardy herbaceous perennial.

Hardiness

Zones 5 - 8.

Habit

Clumping and dense, with leaves so large they create an unexpectedly tropical look for a plant that can be hardy to twenty degrees below zero Fahrenheit.

Rate of Growth

Growth is culture-dependent; see "Culture," below. Fast when conditions are ideal.

Size in ten years

Size is somewhat dependent on culture as well as age, with the largest dimensions where culture is ideal; see "Culture," below. With even only reasonably encouraging conditions, a clump nearly two feet tall and three to four feet wide.

Texture

Tropical: The immense trifoliate leaves dwarf those of any but the most massive hosta, although the hosta clump will have many more leaves, and one of the the largest forms of hosta, 'Empress Wu', can be a couple of feet taller and a yard wider. 

Grown for

its foliage: The large size of the shiny-green trifoliate leaves—to thirty inches across—is deliciously shocking, almost comically so. A happy clump of Arisaema fargesii is likely to elicit smiles and chuckles as much as gasps. The downward-pointing center lobe is larger than the other two, which flank it like giant mouse ears.

 

its flowers, whose tidy white- and maroon-striped hooded pitcher—the spathe—ends in a long, hypodermic-like (but harmless) tip. Only if you lift up the hood do you see a solid red spadix, which projects only slightly above the front lip of the pitcher. Protected so thoroughly from dampening rain and cooling wind, the spadix remains dry and, probably, warmer than the surroundings, which enhances its appeal to the gnats and flies that are thought to be the pollinators.

 

its unpalatability: Arisaema is usually untroubled by browsers above or below ground; its tubers typically are especially immune to predation thanks to their concentration of needle-sharp crystals of calcium oxalate. 

Flowering season

Late Spring into Summer, after the leaves have emerged. My photos were taken on June 21.

Color combinations

With burgundy, white, and green its only colors, Arisaema fargesii goes with everything. Its versatility is enhanced further by the flowers' late-Spring appearance and their fairly quick coverage by the leaves, which are already enormous but still expanding. Once the flowers are hidden, only the mid-green color remains in view.

 

See "Plant partners," below, for options.

Plant partner

Arisaema fargesii is so striking in flower, and both striking and large in foliage: Woe unto any nearby plants that attempt to be more than a stylish phalanx of spear carriers to this extraordinary Cleopatra. Certainly, it would be an embarrassment at best to have other plants in the vicinity whose flowers could be termed "pretty." They will look laughably ignorant of the real drama nearby. Plus, it would be tone deaf to site plants nearby whose calling card is large foliage.

 

Instead, celebrate innumerable opportunities for season-long foliar contrast in size, texture, and color—which is another way of saying, provide a great shade garden context, where a diversity of foliage is usually the majority of the display anyway: gold and green stripes from Hakonechloa macro 'Aureola', feather and filigree from any fern, burgundy foliage and featheriness from Cimicifuga 'Brunette', needliness and gold variegation from a shade-tolerant conifer like Cephalotaxus, broad-leaved variegation from Hedera or—as here—Filipendula, quill-like moundiness from Helleborus multifidus, and celery-like lightness from Xanthorrhiza.

 

It's a special category of plants that will thrive at the front of your Arisaema fargesii clump. Carpeting, creeping, and dense, with small leaves, they must be deep-shade tolerant to fill in at the base of the emerging stems in early Spring, yet quick to reach outward toward greater light as the huge leaves cast more and more shade. Start by choosing among almost any AjugaGalium odoratum, Lysimachia nummularia 'Aurea', Polygonatum humile, and Sedum lineare. Or what about the tiniest dwarf forms of Hosta, such as 'Cracker Crumbs', 'Dragon Tails', and 'Frosted Mouse Ears'? They are all no bigger than forms of Ajuga.

Where to use it in your garden

In my experience, because a clump of Arisaema fargesii bears foliage right to the ground, the colony is only suitable for the front of the bed or—even better—as a foreground specimen skirted by only the lowest of groundcovers. See "Plant partners, above."

 

Because Arisaema tubers typically appreciate or, often, require less or even minimal moisture in Fall and Winter, a prime consideration in siting A. fargesii will be locating where in your garden both surface and ground water will drain toward still lower elevations the quickest. I've sited my clump at the shady end of my main terrace, whose level surface needed to be created by spreading a bed of gravel that, at that end, is already eight or ten inches thick, and becomes thicker still as the underlying grade slopes farther down towards the far side of the terrace. The clump enjoys a planting pocket formed by lifting up one of the terrace's perimeter 2X3' slabs of bluestone, and amending that gravel layer with many shovelsful of soil, compost, and coarse mulch, such that the top of the planting area is a broad mound several inches above the grade of the surrounding bluestone. Above grade and below, then, this spot is as near to the ultimate soil fantasy—moisture-retentive and well-drained—as I could ever hope to supply in my otherwise flat garden that is bountiful with deep and rich but poorly-draining soil.

 

Gardeners whose terrain, soil conditions, and tree canopy is such that they can create a woodland garden on a slope should be able to plant many forms of Arisaema without most of this great-drainage prophylaxis. I envy you!

Culture

Give this species your best: Deep rich soil in a location that receives only morning sun or dappled sun all day, and is—as in "Culture," above—mounded or sloped such that the clump's tubers never experience poor drainage, especially when the they are dormant. In general, Arisaema prefers plenty of moisture Spring into Summer, then reduced or even minimal moisture when dormant in late Summer or Fall through Winter. Poor drainage in any season is likely to be fatal, as would be attempting to grow in soil that is heavy, let alone rife with clay. Instead, ensure that the soil beneath the tubers (not just above and around them) remains readily permeable by digging especially deeply and, as needed, adding gravel and perlite plus coarse all-natural bark mulch, not just compost.

 

Even so, try to choose a location such that the ground a few feet away from the clump is, at least on one side, lower even than the bottom of the tubers. Then, not only will more of the surface water slide away, so will excess water that has already penetrated down to the tubers. 

 

The preference for soil that is moist year-round of our native jack-in-the-pulpit, Arisaema triphyllum, is exceptional, and probably accounts for this species' extremely broad distribution in every state east of the Rockies.  

How to handle it: The Basics

Provided that Arisaema fargesii is planted in culturally-appropriate circumstances (see both "Where to use it" and "Culture," above), the tubers could be planted in Fall as well as Spring in Zones 7 and 8. Plant more deeply in Zones 6 and 5, while keeping in mind that this means that your efforts to ensure excellent underground drainage need to extend that much farther below grade. It's probably safer to plant only in Spring in Zones 6 and 5.

 

If you're purchasing Arisaema fargesii in a pot, from a nursery, it will almost certainly be in leaf, and growing in a pot that is fairly shallow. Provided your soil preparation is deep enough, plant several inches more deeply, burying the lower portions of the leaf stems. If you've purchased Arisaema on-line, you'll probably receive a dormant tuber. In case it isn't clear which side is up, leave the tuber unplanted, and in a bright and warm location until the season's new growth begins to emerge. Then, plant the tuber deeply and on its side, so that the new growth will, just for a short time, emerge horizontally. As it elongates, the growth will right itself soon, yet the still-establishing tuber will be that much more protected from penetrating moisture that first Fall and Winter.

 

Assuming your site preparation, climate, and luck are all in alignment such that your tubers actually establish, they'll find their ideal depth—deeper or shallower—as they grow year by year.  

 

As the clump goes dormant in late Summer into Fall, let the foliage collapse on its own; pull it away from the tubers only after it is fully dried and brown—i.e., when it has already severed from the tubers on its own. After hard frost that first Winter, mound over the planting area with the coarsest mulch you have; I like to use the mixture of small twigs, kindling-sized hunks of logs, and shorn-off-bark that remains after I've stacked one of the delivered loads of firewood. The ultra-cautious might then place a section of heavy cardboard or plywood two feet square over the now completely-below-ground clump in late Fall the first season, and weight it down with a few logs of firewood. Then, surface water is prevented from reaching the tubers directly during Winter, while air-flow through the layer of bark, twigs, and sticks is still maintained.

 

Arisaema is famous for its slowness to emerge in Spring; you  might not detect anything until June. Thick, pointed fully-furled leaves appear first, like tiny green missiles being readied for launching, then the bloom spikes. So, there's no rush in removing any such Winter coverings; instead, time this task so that any companion plants (see "Partners," above) can get going on their normal Spring schedule.  

How to handle it: Another option—or two!

Because Arisaema has a lengthy dormancy, and prefers the driest Fall and Winter you, your soil, and your climate can provide, it might be helpful to carefully dig up the tubers in mid-Fall and store them, dry and frost-free, in any convenient dark spot: a closet, say, or under the bench in a greenhouse provided that they won't get "rained" on as you water plants above. Replant in Spring, as above, after the tubers have already begun sprouting.

 

Judging from the luxurious growth of my clump even when it was growing at the nursery in a pot that wasn't even two-gallon, it must be possible to keep Arisaema fargesii in a container year after year. This solves the challenge of drainage—but by creating the additional task of ensuring enough moisture while the colony is active in Spring and Summer. You can make the watering easier by using a much bigger container; a five-gallon pot wouldn't be too large.    

Quirks and special cases

Arisaema species are usually dioecious, but individual plants often switch between male and female as follows: Youngsters are typically male but mature to female until after flowering and fruiting, and then switch back to male for the next season or two. This is thought to be an energy-saving strategy, in that a male spadix need produce only pollen, whereas, upon pollination, the female spadix would need to produce a spike dense with berry-like fruits.

 

If you have a group of more-or-less equally mature clumps that have flowered but not fruited for a year or two, it's likely that they are stuck in their female phase: With no male handy, their spadices remain unpollinated, so they have energy year after year to stay female. To ensure the pollination that will disrupt this sorority, damage one clump by clipping off most of its leaflets—or even entire leaves—so that the clump is weakened. It is more likely to have only enough energy to return the following year as the pollinating male you need. The female clumps are then—finally!—able to set fruit and, presumably exhausted, return as males the following season. For the next year or two, you may once again have no fruits—but because all the colonies are now male pending the return of enough energy to become female. Your sorority has temporarily become a fraternity. With luck, there will occasionally be a "perfect" year in which only some colonies have become female, and pollination can occur without your intervention.

Variants

To my knowledge, there are no cultivars of Arisaema fargesii, but the genus of nearly two hundred species (and still more when you count the cultivars) abounds with other possibilities whose foliage, overall size, habit, and flowers are so different as to make many of them must-haves. Every detail can vary enormously; it's quite possible to build a collection just around, say, variance in the spadix: Length (hidden within the spathe or projecting beyond it); color; greater or lesser degree of thickness, roundness, or "whip-ness;" and angle of, well, erection (up or up and then outward, up then down, up then noodling around, or outward then projecting wildly at almost any angle). 

 

The spathe is always variegated, and in colors that usually include burgundy-to-brown, green, and white. A. candidissimum is unusual in that its spathe and spadix are both pale pink; the spathe of A. muratae is pale yellow, in delicious contrast with the deep maroon of its spadix. The spadix of A. sikokianum is justifiably legendary: a smooth round knob in a white so bright it seems to be radiating an alien purity. The contrast with the ebony outer surface of the spathe as well as its paler burgundy-striped "lid"—which doesn't cover the spadix at all but, rather, flares upward and outward at the back of the knob, like the no-excess-is-too-excessive collar of a drag version of Ming the Merciless—is shiveringly intense.

 

When Arisaema foliage isn't trifoliate or pedate—shaped like a hand whose fingers are extremely broad—its leaflets are narrower and arranged palmately or even radially along the curved end portions of the leaf stalk. The leaves of some forms are variegated with silver. Leaves of Arisaema fargesii are among the broadest and, overall, most massive, but at under two feet tall are only middling in terms of height: The petioles of Arisaema tortuosum can be four feet tall and, thanks to the bizarre upward-then-noodling-about spathe, its all-green flowers project a foot and more higher.

 

Arisaema triphyllum is one of the very few species native to North America; Asia and Japan are, by far, the center of diversity for this genus. See this peerless reference article for the lay of the land—and then shop at the nursery.

 

To my knowledge, all forms of Arisaema peak in Spring and are more-or-less dormant by Fall. Unlike, say, crocus, there aren't forms that flower in Fall instead, let alone in late Winter. So, while it is mightily tempting to amass a collection of scores of Arisaema species and hybrids, remember that the location of each clump will be a patch of bare ground for much of the year unless you have introduced lower carpeting plants at the front. (See "Plant partners," above.) Further, because Arisaema is typically late to emerge in Spring, and then persists well into Summer, it isn't possible to pair with taller plants that are later still, for compensatory coverage Fall into Winter.   

Availability

Online and, rarely, at "destination" retailers.

Propagation

By separating clumps in early Spring before growth has resumed.

Native habitat

Arisaema fargesii is native to China and Tibet, and was discovered by the French cleric and naturalist Père Paul Guillaume Farges, who lived and botanized in China for decades until his death in 1912. He discovered hundreds of species that were heretofore unknown in Western horticulture. Other plants that bear his name include Abies fargesii, Clematis fargesii, Corylus fargesiiDecaisnea fargesii, Paulownia fargesiiRhododendron fargesii, Salix fargesii and, perhaps even more important, the Fargesia genus of bamboos, which are the only clumpers hardy in Zone 6 and colder.

 
 
FacebookTwitterRSS Feed

Stay in touch!

 

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

 

* indicates required