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or just about any other place where concrete consumes

the dirt and skyscrapers shield the sunshine.- USA Today


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Plant Profiles

The Best Season Ever: Variegated Pencil Tree



The succulent nearly-leafless stems of pencil tree are even wilder in this multi-colored form, 'Sticks on Fire'. By comparison, the striking white-and-green foliage of variegated rockspray cotoneaster is tame and tasteful. Then again, what could possibly outshine a plant whose stems are yellow, and whose leaves are hot pink?




Here's how to grow this easy succulent shrub:


Latin Name

Euphorbia tirucalli 'Sticks on Fire', also known as Euphorbia tirucalli 'Rosea'

Common Name

Variegated pencil tree


Euphorbiaceae, the Poinsettia family.

What kind of plant is it?

Shrubby tender succulent.


Zones 10 - 12. 'Sticks on Fire' will recover from only a few degrees of frost, and only if such below-freezing temperatures are brief: One night that dips to 30 degrees Fahrenheit every few years, maybe—but not once a month during each Winter.  


Shrubby until maturity, when multiple tan-barked trunks become exposed. These give the plant a tree-like habit and scale similar to that of hardy ornamentals such as star magnolia, Magnolia stellata, or Japanese maple, Acer palmatum. Usually taller than wide.  

Rate of Growth


Size in ten years

Size is dependent on culture and climate. Individuals growing in-ground in full sun in a hot and frost-free climate, or when planted permanently in a conservatory bed, will grow faster and larger than those in containers, or growing in-ground in less congenial circumstances. Ultimately, Euphorbia tirucalli 'Sticks on Fire' doesn't grow nearly as large as the straight species: four to eight feet tall and wide, not twenty five to thirty. For the reason why, see "Grown for," below.


Dense, with its distinctive thousands-of-pencils appeal. Unless pruned, older specimens become open, with dense and heavy "clouds" of twiggy growth at the tips of woody trunks.

Grown for

its colorful young stems: The foliage of Euphorbia tirucalli is small and ephemeral; instead, the young stems possess the chlorophyll that enables the species to photosynthesize. Chlorophyll of 'Sticks on Fire' is strikingly slow to develop. Young stems become fully formed in Spring, but don't develop all their chlorophyll until their second season. Until they form their own chlorophyll, then, young stems depend for growth on the chlorophyll and resultant energy of older stems. Overall growth of 'Sticks on Fire' is slower than the straight species, as is ultimate size.


Without the chlorophyll that, otherwise, would reflect light in the green portion of the visible spectrum, as well as mask weaker reflected light from other portions of the spectrum, the stems reflect light of various colors. Indeed, they're a veritable carnival of color. In warm weather, yellow and pink frequencies predominate. In cooler but still frost-free weather, orange, salmon, and red frequencies take over. As a new generation of stems emerges the following Spring, chlorophyll production in the prior season's stems finally catches up: Second-year stems are the same unremarkable green as those of the straight species.


its leaves: Foliage of Euphorbia tirucalli is both sparse and small, and is shed before the end of the growing season, or even sooner if available water becomes scarce. Foliage of 'Sticks on Fire' is as ephemeral as that of the species but, because it never develops chlorophyll, its contribution is strictly ornamental. But what an ornament: The leaves are hot pink!


its naturally twiggy habit: As befitting a species whose chlorophyll is overwhelmingly limited to young stems, Euphorbia tirucalli produces young stems in great quantity. Growth is self-branching, whereby the top of a given segment of stem often produces up to three new segments. Several generations of segments can be formed in a given growing season; if stem segments are lost or cut off, new segments can emerge from dormant buds at the tips of lower stem segments. Even if only a portion of all segments ramify fully, in time, the increase in total "pencils" is tremendous.


its drought tolerance: When growing in-ground, established Euphorbia tirucalli does not need supplemental irrigation. Even better, providing less-than-maximal irrigation also helps increase the intensity of stem coloration. Both cooler temperatures and drought, then, are perceived by the plant as forms of stress, to which the response is the same: Even slower production of green chlorophyll, and increased production of the anthocyanins that reflect yellow, pink, orange, and red.


its imperviousness to most browsers: As is typical for Euphorbias, sap drips readily from cut segments. It is sticky and toxic if eaten, often irritating if in contact with unprotected skin and, potentially, injurious if it comes in contact with eyes. Not surprisingly, most animals don't sample Euphorbia tirucalli twice, although the plant is so palatable for cattle that pencil tree is grown specifically as fodder. Unless goats, donkeys, or cows have access to your 'Sticks on Fire', it's probably safe.


its ease of propagation: Stems root readily. See "Propagation," below.

Flowering season

September to December. The flowers are tiny and yellow, and lack the large and colorful bracts that so often make flowering Euphorbia plants so showy. Euphorbia tirucalli is grown for its its twiggy habit, not its flowers.

Color combinations

If the climate where you're gardening is mild enough to enjoy growing 'Sticks on Fire' outdoors, its irrepressible kaleidescope of colors is, at once, a delight as well as a conundrum. Hues that closely harmonize with the pinks and yellows typical of the hot season (other shades of pink and yellow, plus rose and purple) don't go with the orange, salmon, and red palette the shrub switches to when the weather cools off. Neutrals of green or the grays of monocolored paving such as bluestone, asphalt, or concrete are two options, as is the universal mixer of dark burgundy. 


If frost comes to your climate more often than once every few years, you'll want to keep your 'Sticks on Fire' in a container. Then you can move it into the company of plants that are engaging creatively with whatever colors 'Sticks on Fire' is then celebrating.


See "Plant partners" and "Quirks and special cases," below for suggestions. 

Plant partners

Integrating ‘Sticks on Fire’ into a group scene is a challenge in terms of color, but a no-brainer in terms of texture. The plant’s singular “penciliciousness” and shrubby habit are easy to pair with almost anything, of any scale, as long as it has larger leaves or, in the case of cacti and succulents, green stems that are thick enough to function as leaves and bulky enough to look like them. Welcome plants that communicate “broad” and/or “leafy,” regardless of how they actually do it. The leaves of barrel cacti are as ephemeral as those of ‘Sticks on Fire’, but the cactus’s rotund stems provide the necessary contrast in form. Avoid other hot-climate denizens that have also specialized in a habit that is twiggy, seasonally-deciduous, or skeletal, such as frangipani (Plumeria) or ocotillo (Fouquieria).


Establishing meaningful and pleasing relations with the ever-changing colors of 'Sticks on Fire' and those of its surrounding plants is more tricky. Although the seasonally-changing palette of ‘Sticks on Fire’ is broad, it's not unusual per se. It's common for a woody ornamental—Cercis canadensis, say—to undergo as dramatic and, were they to happen at the same time, incompatible, shifts: Its Spring flowers are candy pink, and its Fall foliage is yellow to orange. 


The difference is that Fall foliage is usually given a pass when it comes to coordination. Bring on orange and red and pink and tan and burgundy simultaneously: The more the merrier. Plantings in frost-free climates need to coordinate more skillfully, because most of them will be stridently colorful for months or even year-round. A few weeks of Fall free-for-all is a welcome antidote to the months of gray and brown to follow, but month after month of pink-next-to-orange-next-to-chrome-yellow would call into question your taste, if not your humanity.


Instead, choose companions for 'Sticks on Fire' whose coloring is a neutral palette of shades of greens, and whose contrast with the Euphorbia is derived from texture and shape and overall size, not color. When growing ‘Sticks on Fire’ in free-draining ground in a frost-free climate, its neighbors will also need to embrace the same climate and habitat. Consider the squatter and denser forms of Agave, plus cacti, Aloe, Aeonium, Crassula, and, of course, others of the enormous euphorbia genus that have contrastingly thick stems, large or well-retained foliage, and, overall, a bulky and dense habit. A bed featuring 'Sticks on Fire', Echinocactus, Opuntia, Agave horridus, andEuphorbia triangularis would be lively, indeed.


The big exception for fearless addition of a strong color would be plants celebrating burgundy and ebony, such as Euphorbia cotinifolia, Philodendron ‘Black Cardinal’, and Dyckia fosteriana ‘Cherry Cola’, Hibiscus acetosella, Phormium 'Black Adder', and Aeonium arboreum 'Zwartkop'. The Philodendron would need to be grown in rich moisture-retentive soil—possibly as a container plant—and the ‘Sticks on Fire’ would need to be large enough to cast it into its preferred dappled shade.


Container-grown 'Sticks on Fire', by contrast, is a mobile party-in-a-pot. Move it to where its current coloration is now working best with that of its neighbors. As long as the plant doesn't experience frost, it could spend a few weeks in late Spring near your pink peonies, then get moved nearer to yellow dahlias for the Summer. When the weather cools off (or you bring the plant indoors for the Winter), group 'Sticks on Fire' with salmon-flowered Euphorbia millii or Schlumbergera truncata.

Where to use it in your garden

'Sticks on Fire' that's growing in a container can be set anywhere in full sun that the colors of the surrounding horticulture and hardscape are congenial. When growing in-ground, 'Sticks on Fire' is irresistible as a "Aren't I just fabulous?" accent in dry, full-sun gardens.


If you're aesthetically ambitious—and can also tolerate the release of all the dripping sap that pruning would cause—a hedge of 'Sticks on Fire' would be an achievement worthy of magazine coverage.


All possible sun and heat, and almost any soil as long as there is excellent drainage year-round. As is typical for succulents, poor drainage would be fatal in any season, especially when temperatures are cool enough that the plant is dormant. Richer soils produce looser and faster growth that becomes even more floppy than can happen to this species even in the driest circumstances. With such dense and numerous succulent twigs, the weight of young growth can exceed the "carrying capacity" of the woody stems below. The result can be leaning trunks and somewhat pendulous green growth. See "How to handle it," below. 

How to handle it: The Basics.

Plant in Spring. This is a heat- and drought-tolerant species, so new plants don't need much water to establish. Allow to grow freely for a year or two, then, before growth would normally resume in Spring, prune away most of the last year's growth. This encourages plentiful formation of new growth, which is the most colorful. It also controls size, which might be a concern if the shrub is sited near a walkway (see "Downsides," below). Pruning also helps the shrub stay bushy, and makes it less likely to shed lower (and, therefore, older) growth and reveal bare woody stems.


If growing 'Sticks on Fire' in a container, be aware that the succulent green growth is likely to be much heavier than the shrub's rootball and container. Site carefully so the potted plant doesn't tip over from weight imbalance, or be tipped over by wind. It might be prudent to place a stake in the ground, adjacent to the container, such that you can tie one of the shrub's major branches to it and, thereby, stabilize container and shrub alike. The challenge of handling such a potentially tall and top-heavy container plant is often reason enough to keep the plant pruned, as above, so it doesn't grow awkwardly tall in the first place.  

How to handle: Another option—or two!

In the hot, dry climates where Euphorbia tirucalli thrives in-ground, old and overgrown specimens are common. Even the comparatively compact 'Sticks on Fire' could grow into a large multi-trunked bush, with heavily-"penciled" stems leaning outward unattractively.


You have a few options when attempting to renew such an old and overgrown pencil tree. Although you can do renewal pruning at any time, if you can wait until the plant is in active growth, you'll minimize the wait for new green growth to form at the resultant bare ends of cut branches. Wear protective eyegear to prevent sap from any higher cuts from reaching your eyes; wear gloves and protective clothing as needed to keep sap from your skin. If there is some young growth emerging directly from the base, you can confidently prune or saw away woody stems. If such basal new growth isn't present, it could be safer to cut down just one or two of the out-of-bounds stems a year.


Spray water on the stumps of cut branches to wash away sap that is already released or will be shortly, then allow the cuts to dry and callus, thereby preventing further sap release.


Another option could be to remove only the outward branches and trunks, retaining a central one that is intended to be the trunk of a resultant small tree. Leave the "foliage" canopy atop that trunk, pruning it back lightly in early Spring, as you would do with a shrub of 'Sticks on Fire', to control canopy size and also encourage production of the colorful new pencils.


Euphorbia tirucalli can be used as a hedge in hot dry climates, such as Africa and the Indian subcontinent, where a fence or wall might be unaffordable. A hedge of 'Sticks on Fire' would be at once more compact and more colorful. Plant young plants every foot, and let them grow two or three years on their own. Thereafter, prune annually to keep growth full to the ground, as well as control width and height. If you prune in early Spring, while the plant is still dormant, you're more likely to reduce, at least a bit, the hassle of the messy sap that will be released by the pruning the plant when it's fully active.   

Quirks and special cases

The salmon-centric colors the shrub's new stems adopt in cool weather can be encouraged to stick around, at least somewhat, when the weather warms up. The key is to realize that the salmon color is a sign of a degree of mild stress; for this heat-loving shrub, even temperatures in the fifties and forties are stressful. Not fatal or even damaging, mind you; just not ideal.


If the weather is hot, another stress you could try to bring about is by ensuring that the shrub experiences a drought. To enhance the shrub's experience of drought, grow 'Sticks on Fire' in sandy or even gravelly soil. If you grow it in a container, choose one that's unglazed terracotta; the pot itself will wick water away from the soil, and evaporate it readily into the surrounding air. Site the plant where it as well as its container receives plenty of possible sun, heat, and air motion. If you grow 'Sticks on Fire' in-ground, plant in the same sandy or gravelly soil, in a location that also receives all sun, heat, and breeze. Also try to choose a bed that has a slope, so any surface water is just as likely to flow away from the shrub as it is to penetrate the soil.


True, the shrub will need some moisture to grow, let alone remain in good condition. Without any moisture at all, the stems will eventually shrivel. Fostering the maximum intensity and longevity of salmon-centric display, then, is a matter of experimentation. It's probaby best to begin by providing conditions of maximal intensity of drought; you can always provide occasional supplemental water.


One handy benefit of ensuring minimal water is that the shrub's growth will be more compact, helping you avoid growing—and pruning—a pencil tree whose stems are overly long and droopy from a surfeit of hydration.


The irritating sap is at best an inconvenience and, at worst, a real hazard. Wear protective goggles and clothing when working on Euphorbia tirucalli, especially large and old plants. In mild climates, they can grow large enough to function as small trees, with branches high enough to be walked under. Sap can drip from the "stump" of even the smallest cut segment, making a mess of a walkway (or the hair of a passerby) below. Any sap that drips into an upturned eye can be reason for a trip to the emergency room. Euphorbia tirucalli large enough to have become arboreal in habit can be dramatic when sited well back in a bed deep enough to keep the plant entirely away from passersby; remove or renewal-prune any pencil tree sited where it can be walked under. See above, "How to handle it: Another option—or two!"


Regardless of the size of the shrub, pruning Euphorbia tirucalli is still an inherently messy task: The sap oozing from pruned segments will soon gum up the pruners, or irritate unprotected skin, or turn the sleeves and gloves and pants-legs that need to protect skin into sticky messes. Promptly wash tools, gloves, clothing, let alone any exposed skin, to clean off the sap before it dries. A hedge of pencil plant is a testament to endurance.     


To my knowledge, 'Sticks on Fire' is the only named form of Euphorbia tirucalli. Euphorbia tirucalli 'Rosea' is believed to be the same as 'Sticks on Fire'.


On-line as well as at retailers.


By cuttings. Select branches old enough to have all-green stem segments, and prune them from the shrub when it is in active growth. Swish them gently in a container of water until they stop leaking sap, then let them dry in the sun for a day or two, so that their cut ends callus. Plant the branches a couple of inches deep in barely damp, soil-less potting medium. Don't water again until the medium is notably drier; you can tell when it's time to water because the pot will feel notably lighter. Be stingy with watering; when in doubt, don't. Wait until new leaves or segments begin emerging from stem tips before watering regularly. Even then, allow soil to become dry between waterings.    

Native habitat

Euphorbia tirucalli is native to Africa. 'Sticks on Fire' was brought from South Africa to California in the late 1980s. 

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