A Gardening Journal

The Best Season Ever: Ricepaper Plant

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The first snow!  Finally, the garden is slowing down a bit.  Just the time to highlight some of the plants that couldn't be featured when the weather was warm, and new plants were peaking each day, day after day.

 

Today, the first in the series:  Ricepaper plant.  Tetrapanax papyrifer may be native to Taiwan—Zone 9 and 10—but you can grow it all through Zone 6.  And that means right here in New England.  These pictures show my colony in late September; it had never been more spectacular.

 

The picture above is of an emerging leaf, so copper with fuzz it looks almost like metalwork.  When younger still, Tetrapanax foliage is even more sculptural, with the high, proud, and vaguely menacing profile of an icon of some obscure tropical cult. 

 

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The foliage unfurls into the largest leaves of any plant that's even remotely hardy north of Miami.  A single leaf can be three feet across, a living umbrella at the end of a two-foot stem.

 

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But the one thing never to do is to touch any portion of Tetrapanax.  That cinnamon-colored fuzz is released into the air with the slightest jostle and, when inhaled, brings on a serious coughing fit 

 

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Below are the many caveats and options that help make growing such a spectacular and essential plant practical—or at least possible.  In establishing and then caring for your colony, you'll find yourself incorporating some of the skills that you may have already learned when tending to fig trees, mophead hydrangeas, bamboo, and empress trees.  Read on!

 

Here's how to grow this bizarre but beautiful shrub:

 

Latin name

Tetrapanax papyrifer / Tetrapanax papyriferus / Tetrapanax papyrifera.  This cultivar is 'Steroidal Giant'.

Common name

Ricepaper plant

Family

Araliaceae, the Aralia family.

What kind of plant is it

Zone 8 and warmer, an evergreen shrub or small tree.  Zone 8 to Zone 6 (with protection—see "How to handle it"), a woody perennial.  In all cases, legendarily stoloniferous.  Compared to ricepaper plant, sumac and trumpet vine are timid amateurs.

Hardiness

Zones 6, with protection, to 11.

Habit

Fuzzy cane-like stems arise from astonishingly wide-spreading roots, and are topped with spectacular and immense palmate leaves.  In Zones 7b and warmer, above-ground stems can be Winter-hardy, and become old enough to branch and, where the growing season is long enough, produce immense terminal inflorescences, typical in scale for Aralia, composed of innumerable spherical umbels of tiny buff-white flowers.  In Zone 7a and colder, top growth is typically killed to the ground each season; then the new stems remain single and cane-like, and do not produce the inflorescence.  

Rate of growth

Very fast, almost unnervingly so.

Size in ten years

Size depends on hardiness and culture.  In rich soil and full sun, even when growing where the colony is able to persist only as a die-back woody perennial, canes can still reach eight feet or more in a season.  Stoloniferous activity seems undiminished where the plant is a die-back—and may actually be increased because of it:  The die-back of the stems also stops their production of a hormone that inhibits growth of other stems closer to the ground.  Uncontrolled, an established clump can spread readily into a loose-limbed colony twenty feet across or more. 

 

In the same circumstances in a climate where top-growth is hardy, the woody stems can grow fifteen to twenty feet.  Stoloniferous growth is still ever-present. 

Texture

Massively tropical and nearly palm-like, with overlapping and, appropriately, palmate leaves that tend to cluster at the upper portion of the canes.  Although some bananas, elephant ears, cannas, and palms can grow larger leaves, few if any have near the hardiness of Tetrapanax.  For bringing "tropicalismo" energy to temperate climate gardens, ricepaper plant is the best combination of hardiness, foliage size, and overall scale despite its cough-inducing fuzz and various challenges—or, rather, options–for overwintering and Spring grooming.

Grown for

its foliage: Massive palmate leaves—the largest of any species that is even remotely hardy colder than Zone 7—can be three feet across and more.  The entire emerging leaf is covered in showy tan fuzz, as is the leaf stem, veins of mature leaves, and the young stems of the plant itself.  The fuzz is so easily dislodged that it becomes airborne at the slightest brush; it is peculiarly irritating when inhaled, although, to my knowledge, not actually harmful.  Wear a mask when handling Tetrapanax, and caution garden visitors not to touch its growth.

 

in nearly frost-free climates—Zone 9 and warmer—its late Fall and Winter flowers:  As are typical for many other species in the Araliaceae family, small white or off-white flowers are grouped into spherical umbels, which are, in turn, arrayed on a large and much-branched panicle that can be several feet tall and nearly as wide. 

 

its imperviousness to browsers:  Perhaps on account of the irritating fuzz, the immense leaves are, in my experience, never chewed, or even sampled.

 

its options for handling:  Depending on the climate, as well as your energy and ambition, Tetrapanax can thrive as a permanently-branched shrub or small tree, a woody die-back colony-former similar in habit and scale to sumac, a perennial that returns from the roots, or a container specimen.   

Flowering season

Late Fall into Winter:  Unless you're gardening in nearly frost-free climates, cold weather is likely to hussle the plant into dormancy long before it is ready to flower.  Tetrapanax will usually flower when growing along the coast of the Gulf of Mexico, for example, but not hundreds of miles inland (let alone in the mid-Atlantic, or here in New England).  Enjoy flowering Tetrapanax in Houston, Texas; but not in Dallas.  Flowering also doesn't occur on stems that have lived only in the current season, so plants do not flower that die back each Winter or, for one reason or another—see "How to handle it," below—are cut to the ground each Spring.

Color combinations

Tetrapanax has unparalleled prominence in terms of foliage and overall bulk, but because that foliage is green and the flowers are off-white, their coloristic presence is neutral.  The cinnamon-colored fuzz is quite showy, especially on emerging foliage, so welcomes neighboring plants that celebrate, or at least reference, shades of tan and mahogany.  The challenges of restraining the upward and outward growth of Tetrapanax could preclude partners that would be readily overwhelmed.  See "Partner plants," below, for possibilities that are practical, or at least plausible. 

Partner plants

Because neighboring plants could be swamped by unrestrained outward-bound Tetrapanax growth, partner plants need to be considered carefully.  Because Tetrapanax is not showy in the Winter in climates colder than Zone 8, one option is to partner with warm-weather container plants, which would not be vulnerable to being shaded out by the immense leaves, nor crowded out by the profuse shoots and roots.  The immense palmate Tetrapanax leaves would be excellent textural contrast to containered ferns or grasses, whereas additional large-leaved tropicals are likely to appear repetitive at best, uninspired at worst.  Bring out your Boston fern and set it, on its stand, on the sheltered and semi-shady side of your colony of Tetrapanax.  Even better, add one of the tender "footed" ferns to your conservatory collection.  Their extensive above-ground rhizomes are covered in colorful "fur" that, in some forms, is a perfect match for the cinnamon fuzz of Tetrapanax.  The fur of bear's paw, Polypodium aureum, is a warm brown.  That of rabbit's-foot fern, Davallia canariensis, is lighter tan.  Gardeners in the humid tropics of Zones 10 and 11 could choose the giant mule's-foot fern, Angiopteris evecta, whose furry base can become larger than a whisky barrel, and whose fronds can be twenty feet long!   

 

Another strategy would be to grow an herbaceous vine up into the quickly-ascending Tetrapanax canes, for contrast in form and texture if not, so much, color.  One of my hardy passion vines, Passiflora lutea, is an eager explorer of my main colony of Tetrapanax.

 

Yet another option is to grow Tetrapanax up through a shade-tolerant groundcover that doesn't mind being pierced by its shoots.  My prostrate stranvaesia, Photinia davidiana 'Prostrata', has served very well in this capacity.  Its dense evergreen foliage and twiggy habit may well be contributing to the vigor of this particular colony of Tetrapanax by acting as a living mulch and wind-baffle for the colony's bottom eighteen inches.  Its coloring doesn't call out to the cinnamon fuzz, but the small pointed leaves, very similar to those of Ficus benjamina, are excellent contrast. 

Where to use it in your garden

Controlling Tetrapanax is essential to creating a presence for it in your garden that is tolerable, not just striking.  See "How to handle it" for many options.  The regular access to the colony that nearly all of them require means that Tetrapanax should be sited so at least part of the colony is directly accessible from adjacent lawn or paving. 

 

Because establishment in cooler climates is helped by Winter shelter (again, see "How to handle it"), locating a colony on the south or west side of buildings is usually essential.  But the size of the foliage, and the height of growth from mid-Summer on, means that Tetrapanax will quickly grow high enough to block windows or spread widely enough to block doors.  In some sites, this could be a positive: The colony will protect the first floor of the adjacent structure from hot afternoon sun or, if you clip off lower foliage, provide a shady canopy for doorways and windows.  In the rare event that your building has a west- or south-facing wall that is both high as well as unfenestrated, congratulations:  You're well on the way to having the perfect site for Tetrapanax.  Get up to speed on controlling its spread along the unwalled margin of its desired area, and you're home free.

 

And then there are the aesthetics.  Even if you allow just one cane to grow, it can sprout three-foot leaves as big as those of umbrella palms, and can grow to ten feet or more by Summer's end.  How will this immense display of gigantic foliage coordinate with its surroundings?  It's unrealistic to think of Tetrapanax as anything other than a loud-and-proud star.  As you think of all of the practical aspects of siting, consider as well which location gives this astounding species the unapologetically dramatic context it needs.

Culture

Sun or part shade in almost any well-draining soil; faster and larger growth—but also more rampantly spreading roots—in rich soil with plenty of water in Summer.  As usual, excellent drainage in Winter is essential to establishment of a colony in a location that is colder than Zone 8.

How to handle it: The Basics

The foliage fuzz becomes airborne at the slightest handling, which would make Tetrapanax plants for sale at a retail nursery a nightmare:  Imagine the damage to business as customers become wracked by coughs soon after they fondle one of the irresistibly enormous leaves.  Plants are more likely to be available only on-line, and will therefore be small.  Although established colonies of Tetrapanax can be relentlessly vigorous, getting these starter plants of Tetrapanax through their first Winter can be tricky. 

 

Plant in late Spring, as deep as you can while still letting the top couple of inches of leafy stem remain above ground.  Feed and water diligently, with the goal of stimulating the plant into maximal size before arrival of frost.  After there has been enough frost to turn the leaves brown, put on a surgical mask to reduce your chances of inhaling the fuzz, and then collect the fallen leaves or cut them from the cane-like stem.  You can compost them; just shovel soil or additional compost on top of them so they or their fuzz don't blow around.  

 

Then make a foot-high "volcano" of mulch around the young plant's stem(s).  Keeping the plant and its immediate surroundings dry will enhance Winter hardiness so, on a warm and dry Indian Summer day, cut off the stems at the surface of the mulch, and lay a yard-square piece of cardboard atop the vulcano.  Crease the cardboard so it forms a sloping "roof" atop the mulch, like that of a Fifty's Modern suburban house.  Fill under the open sides of the roof with additional mulch, and lay a few large branches or logs of firewood atop the cardboard to hold it in place through the Winter.  The cardboard will greatly reduce the ability of rain or snow to penetrate into the mulch surrounding the young Tetrapanax, let alone into the soil.

 

Remove the cardboard as Spring begins to warm up; I can't resist scuffling into the mulch to locate the Tetrapanax stems, so go right ahead and explore.  More than likely new shoots will arise from the roots not the stem, so take care not to dislodge them.

 

You can mulch less the second Winter, and omit the cardboard "roof," too.  In subsequent Springs, my main colony in my cold Zone 7 garden demonstrated how self-reliant it had become by producing sprouts a few feet from the mother clump.  And then, a few yards away.  Now my focus has shifted entirely from protecting my Tetrapanax to keeping it under control.

 

Another option for reliable establishment is to grow the youngster in a pot the first year, during which it might become three to five feet tall by October.  Bring it into shelter before frost, first taking care to cut off all the leaves to reduce its bulk.  You can risk keeping it warm and in reasonable light, whereupon new leaves will soon develop.  But these are likely to outgrow your available space and, besides, there's the damned airborne fuzz to contend with.  Better, then, to keep the plant in a cool but frost-free location so it stays leafless and dormant. When warm weather returns, plant it a permanent location, and handle as above.

 

If growing Tetrapanax in climates colder than Zone 8, the stems will usually shed their leaves for the Winter; there is no Fall color.  Without the immensity of the foliage, the comparative skinniness and sparseness of the bare canes is a shock.  They are not especially showy; Tetrapanax is not the plant to supply Winter interest.

 

Don't rush to tidy up established colonies in Spring because, in early Spring, stems or stem-tips that have become Winter-killed don't look much different than living ones.  Instead, handle as you would Hydrangea macrophylla:  Wait until the tips of stems that have remained viable have announced as much by producing new leaves.  The tips of dead stems (or the dead tips of otherwise living stems) will then be glaringly evident, and can be quickly clipped away. 

 

Tetrapanax blooms too late in the Fall for the immense inflorescences to be produced on colonies growing in climates much colder than Zone 9.  Even then, flowering typically occurs only at the tips of the woody stems that have remained viable from previous years, not on first-year sprouts.  All the more reason to be hesitant, at least in Zone 9 and warmer, about cutting supposedly dead stems all the way to the ground.  Flowering can also occur at the tips of side branches that will form from the portion of the stem that is viable lower down. 

 

If you're gardening at the cold margins of where Tetrapanax might be able to flower—in Zone 8, say—you could try protecting the woody stems year-to-year, and especially their tips, in hopes of giving your colony just the additional bit of mildness it needs to flower.  You'd need to be somewhat of a maniac to attempt this, in that the stems could be six, eight, ten feet tall, and, as I say, it's the very tips that are the most important part to protect.  Wait until frost has damaged the leaves and, therefore, has encouraged the plant into a degree of dormancy.  Cut the foliage off, tie adjacent stems together where possible, and wrap them in industrial carpet, with the carpet's rubbery backing facing outward, to make a cylinder a foot or more wide.  Tie the carpet securely so it stays wrapped upon itself.  Fill the cylinder with some sort of small-sized mulch that you can pour in at the top, such cocoa or buckwheat hulls, and then tie a black plastic contractor bag over the top of the carpet cylinder to keep out rain or snow.  After danger of hard Winter weather is past, untie the carpeting (therefore releasing a cascade of mulch down into your shoes, true) to expose the stems to sun and warmth.  

 

I implemented this heroic protection strategy one Winter, but the season was unusually severe, and the top growth was killed to the ground, anyway.  Then again, I'm only gardening in cold Zone 7, so the gambit wasn't likely to have worked in the first place:  Killing frost is normal by November, and Tetrapanax is unlikely to be in bloom until later.  Even if I'd preserved viable stem tips through to Spring, any inflorescences they might have been able to produce would have been prematurely killed by Fall frost.   

 

After you've established Tetrapanax, and implemented whichever of the pruning and Winter protections strategies (see above as well as "Other Options," below) seem practical, your next decisions will be about how to control the beast.  Take guidance from the standard control methods for bamboo.  Clip off the far-ranging shoots as soon as you can; smaller ones can be pulled up.  (If only they were edible, so there would be a use for the crop.)  They grow quickly, and quickly become woody at the base; clipping is easiest when they are small and still soft.  An underground barrier is another option, as is planting Tetrapanax near extant walls for at least partial control.  The roots can explore underground for many yards before revealing their presence by sending up a shoot, so siting near an expanse of paving won't, in itself, be a help.  This Spring, I pulled up a shoot at the far side of my terrace from the mother clump: twenty feet away.  Tetrapanax roots have none of the spear-like ferocity of bamboo rhizomes, so they don't have the bamboo's barrier-busting sharpness.  Barrier rigidity is still important, but so is a tight seal all around the colony, lest the small root tips find an opening.  

 

My preference is for regular clipping of shoots instead of a barrier, which would take too much digging and commitment to install and monitor.  

 

In Zone 8 and warmer, hardiness isn't a problem, and so Tetrapanax could also be grown as a free-standing colony in the middle of a large lawn.  New shoots will be clipped by the regular lawn mowing.  With such far-spreading roots, you'll need a lot of room to rely on this method alone: Allow at least twenty-five feet of lawn all around the colony. 

How to handle it: Another option—or two?

As in "How to Handle It" above, stems of Tetrapanax colonies in climates severe enough to produce Winter-killed stems or stem-tips can sometimes be handled as you would a fruiting fig (by overwintering with a carpet-cylinder), a mophead hydrangea (by clipping dead tips only after the living ones have revealed themselves), or bamboo (by clipping off out-of-bounds shoots, growing the colony within a large lawn, or installing in-ground barriers).  

 

The foliage of new growth that is produced by winter-killed plants—which is Nature's way of coppicing or pollarding, with you following up with your pruners to remove the portions that Nature has already slated for removal—is reportedly much larger than that produced by colonies growing in climates so mild that Winter-kill doesn't occur.  This suggests that Tetrapanax might also be handled like an empress tree.  The heart-shaped leaves of Paulownia tomentosa aren't small even on free-range trees: They can be six inches or more across.  On trees that are sawn back to a stump yearly, the leaves on new stems can be over a foot across.  But if only one of those new stems is permitted to grow, their leaves can be over two feet across.

 

My colony of Tetrapanax always receives Winter-kill to an extent; in severe years, stems are killed right to the ground.  And its leaves are always gigantic: nearly three feet across.  How much of their size is related to the age of the colony?  How much to the richness of the soil, the ready access to ground moisture, and the sunny-but-sheltered site?  And how much to the Winter coppicing that Nature always provides, more or less?  And how much bigger still would the foliage be if I let remain only one of the stems that regrow each Spring as a result of that coppicing?  Then all the resources being absorbed by the colony's scarily wide-spreading roots would be shunted just to that one outlet.  It would be a horticultural gavage—the force-feeding of a goose to make fois gras.  This Spring, I must perform this experiment.

Any (other) quirks or special cases?

Given the capability of Tetrapanax to propagate itself outward, yard after yard, via root shoots, it's a comfort that the plant only flowers in climates that are nearly frost-free.  There's no chance, then, of Tetrapanax growing north of, oh, Atlanta to propagate by self-sown seeds, too.  This provides no comfort if the plant is able to flower and fruit, though.  I don't come across dismayed notices of self-sowing Tetrapanax, only root-sprouting Tetrapanax.  Or are self-sown seedlings actually the reason that some plants have been reported to root-sprout more than thirty feet away from the mother colony? 

 

Oh yes:  That "ricepaper" thing.  The cane-like stems are filled with a thick cylindrical core of white pith that is so uniform and rubbery-dense it could have been the foam insulation you spray out of a can.  The pith can be mounted on a rotating spit, such that long thin sheets can be sliced from it.  True ricepaper is made from rice straw: The stems of rice plants.  There is no rice in the paper made from Tetrapanax, which could more correctly be called pith-paper.  But that only sounds like the insensitive punchline about somebody with a lisp.  So, "ricepaper" plant it remains. 

Downsides

Rampant stoloniferousness, as well as the very irritating (but, far as I know, not ultimately harmful) fuzz.  Regardless, I wouldn't be without this monster.

Variants

The straight species of Tetrapanax papyrifer is smaller only by comparison; this is still a thrillingly huge plant. 

 

The tips of the lobes of the emerging leaves of Tetrapanax papyrifer  'Variegata' are cream, with much of the rest of the lobe irregularly variegated in dark- and gray-green; as the leaves mature, the extent of the cream is reduced in favor of more gray-green.  This cultivar has been reported in Australia and Japan, and is listed in the Royal Horticultural Society's database.  To date, I've been unable to locate a source, and have been able to locate only a single picture on-line.  Among North American plant-o-holics, the cultivar has the mythical status of Tolkien's White Tree of Gondor.      

 

Availability

On-line.

Propagation

By division in Spring and early Summer, as new stems begin appearing all over the place.  With a sharp vertical jab of a shovel, sever the root that connects a new shoot and its mother clump, and sever it again at the far side.  Lift the rooted shoot to pot it up or transplant to its new location.

Native habitat

Tetrapanax papyifer is native to Taiwan.  Given its stunning vigor and success at outward spread, why isn't the entire island covered in it? 

 
 
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