Purple Passion Plant: The April 2022 Houseplant of the Month

Photo: Prill, depositphotos

By Larry Hodgson

Quite the surprising plant, this one. I know of lots of white velvety plants, brown velvety plants and even a few yellow velvety plants, but I can’t think of any other that is purple and velvety.

The purple hairs that give the plant its velvety appearance stand straight up from the leaves and stems and are of a particularly brilliant shade. Since the leaf produces its full complement of “fuzz” from the moment it is produced, color is always most concentrated on new growth. As the leaf becomes wider and longer, the hairs spread apart and the surface starts to appear more and more green and less and less purple. For maximum color, pinch regularly to stimulate lots of fresh new growth!

The purple passion plant not an uncommon houseplant, nor is it rare. It’s just sort of a standard houseplant, one that’s been grown for that purpose for over a century.

Purple passion plant is probably this plants most common name, but you may also know it as velvet plant, royal velvet plant or purple passion vine.

Description

The purple passion plant is a variable plant and can be upright with large leaves or spreading (even creeping or trailing) with smaller ones. That depends on the clone you choose as well as the growing conditions. It’s often more compact under brighter light.

It can reach up to 8 feet (2.5 m) tall . . . but that would be in the wild. You never see them anywhere near that size in culture. The thinner-stemmed forms with a spreading or creeping habit rarely reach more than 8 inches (20 cm) in height, but can spread out to lengths of 6 feet (2 m) or more. Or trail from a hanging pot to that length. Indeed, you could also fix them to a trellis or other support and encourage its stems to climb.

The elliptic leaves range from narrow to broad and are lightly to heavily toothed along the margin. They’re very dark green when fully formed, with purple veins.

The purple passion plant flowers quite readily. Buds are rather like those of dandelions (not surprisingly, since the two are close relatives), but are covered in purple fuzz. They form in open clusters at the stem tips, especially in late spring and summer.

While the purple passion plant is an Asteraceae (in the daisy family), the bloom doesn’t look much like a daisy. There is no circle of broad ray flowers around the cluster and the narrow orange flowers in the center aren’t very densely packed.

They soon turn into puffs of white fuzz that break apart into the same type of seed-bearing “parachute” as the dandelion.

Most people cut off the blooms, though, before they ever make it to producing seeds, as they have a disagreeable musty scent. Still, this is only something you would notice with your nose practically sticking into the flower. There is another reason for removing them, though. Once a stem has bloomed, it tends to go into decline: pinching off the flowers can keep it thriving longer.

Don’t expect the purple passion plant to be very long-lived. Its base becomes woody over time and eventually stops producing strong new growth, a sign it is time to renew it through cuttings. (See Multiplication below.)

Warning. The purple passion plant has been known to escape from culture in tropical humid climates and exists as a weed in Africa, Australia, South America, Mesoamerica and Florida. If you live in such an area and want to plant it outdoors, make sure you never let it go to seed!

What Is It?

That is certainly the question.

Botanists have been arguing about the proper botanical name of this plant for half a century. The name most often seen is Gynura aurantiaca and indeed, that’s the name I’ll use here. But you also see G. sarmentosa, G. procumbens and G. bicolor.

For the purpose of this article, I’ll follow the lead of the New Royal Horticultural Society Dictionary of Gardening. Therefore, I’ll be calling the species itself G. aurantiaca. When I need to refer specifically to the more common spreading, smaller-leaved variety, I’ll use the name G. aurantiaca ‘Purple Passion’.

Gynura aurantiaca: This is the “true” species. It’s an upright-growing plant to 3 to 5 feet (90 à 150 cm) with thick, almost succulent stems and large elliptical leaves that are only slightly toothed along the edges. Because of its upright habit, it is often called velvet tree or purple passion tree. The purple coloration is much more obvious on new growth: mature leaves and stems seem to have only a dusting of purple hairs, although brighter light brings out the best coloration. It may need staking to remain upright. It’s not that widely available, but you can still find it in selected nurseries, especially those specializing in tropical plants for summer use outdoors.

Gynura aurantiaca ‘Purple Passion’ : This is the variety by far most commonly seen in homes and gardens. You may see it called it G. auriantiaca ‘Sarmentosa’, G. sarmentosa or G. procumbens, and there is some speculation that it might be a hybrid between G. aurantiaca and another species, G. procumbens. However, the New Royal Horticultural Society Dictionary of Gardening suggests otherwise. It’s a plant with smaller, narrower leaves, much more deeply toothed than its treelike brother, and well-covered with purple hair. Also, the stems are clearly “procumbent.” That is, while they may grow upwards at first, they then bend and start to creep over the ground (or dangle from the pot if grown in a basket). If you’re growing a purple passion plant, 10 to 1 it’s this one.

G. aurantiaca was so named by Swiss botanist Augustin Pyramus de Candolle who discovered it on a voyage to Southeast Asia in 1838. It’s not sure if he discovered it himself or studied specimens in one of the university herbariums where he worked in Java. However, it is known to be native to that island and to Sumatra.

De Candolle placed the new species in the already existing genus Gynura, from the Greek “ghyné” (female) and “ourà” (tail), referring to the elongated stigma of the flowers. He gave it the epithet “aurantiaca,” meaning orange, because of the color of the blooms.

One has to wonder why de Candolle didn’t call this plant something more aligned with its stunning foliage color, like “purpurea,” or “violacea,” but you have to remember that, until very recently, botanical plant identification was largely based on the appearance of the flower, not the foliage.

Cultivars

Besides the two variants already mentioned, there is also a variegated variety of G. aurantiaca ‘Purple Passion’ called G. aurantiaca ‘Pink Ice’ (or ‘Aureo-variegata’), with bright pink leaf edge marbling turning cream at maturity. The variegation is highly irregular. Some stems bear leaves with little of it, others more. Still others come in entirely pink . . . and should be removed, as they lack chlorophyll entirely. That means they don’t carry out photosynthesis, so they drain the plant’s resources.

In general, ‘Pink Ice’ tends to be a weaker plant than G. aurantiaca ‘Purple Passion’ and needs an extra bit of TLC and some very careful pruning to thrive.

Caring for a Purple Passion Plant

The purple passion plant is not difficult to grow, but it’s a fast-growing plant does require a bit of upkeep, especially when it comes to grooming. Nor must you ever let it dry out entirely.

Here’s more about how to grow it:

Light: Give this plant bright to medium light. It will tolerate full sun, although you may need to acclimatize it first. However, good light is sufficient and the best that many indoor locations can offer at any rate! It will not do well in shade.

An east window, or a north one in summer, would be perfect. You might want to move it back from a south or west one during the heat of the day ove the summer months or draw a curtain between it and the blazing sun at that time.

New leaves that are more green than purple, or weak, stretching stems, can be an indication the plant is not getting enough light.

While your plant will enjoy a summer outdoors in most climates, it’s best to avoid full sun there: shade or partial shade is best.

Watering: Basic houseplant watering is fine. Just follow the golden rule of watering, that is, giving a thorough watering when the soil is dry to the touch. It will tolerate an occasional drought, but may lose many leaves in the process. Certainly, when the leaves start to wilt, give it a good soaking. You can let it get a bit drier in the winter than the summer.

Curling leaves or brown edges can be indications the plant is not getting enough water, although they could also be signs of dry air.

Atmospheric Humidity: The purple passion plant likes fairly humid air: a relative humidity of 50% or so, so may need a bit of a boost in the drier months of the year. A room humidifier would be the easiest way to go. However, excess humidity, especially when combined with hot temperatures, can lead to collapse: this is not a plant for terrariums!

As mentioned under watering, curling leaves or brown edges can be signs of insufficient atmospheric humidity.

Fertilizer: You can use the fertilizer of your choice, as this is not a plant with specific mineral needs beyond the norm. However, reduce the rate to about ¼ of that indicated on the label, as too much fertilizer leads to rangy, unhealthy growth. Only fertilize in the spring and summer.

Temperature: This plant likes mid-range temperatures, about 65–80°F (18–26°C). It doesn’t mind a bit of a drop in winter, but nothing too dramatic. Say, to 55°F (13°C) at night. It dislikes hot, humid air at any time. That can result in rot and rot can be fatal. Nor does it at all appreciate cold . . . which can, again, result in rot. Think of this way: if you’re comfortable, your purple passion plant will be comfortable!

Repotting: Transplant mature plants every 2 years or so into regular potting soil. Young ones can outgrow their pots in only a few months and therefore may need to be potted up more than once a year. Avoid repotting during the shortest days of the year, if possible.

Grooming: Routinely remove yellowing or brown leaves and dead or dying stems. This is not necessarily a sign of trouble. After all, leaves don’t live forever!

You can go heavy on pruning when it comes to this plant. It grows quite quickly and needs some control. Plus, branches that bloom tend to die back, so it’s best to pinch any flower buds off. In fact, pinching any stem will help slow down the plant’s growth and stimulate branching, leading to a denser, more attractive plant.

Keeping the plant looking good in a hanging basket can be a challenge. Not that the purple passion plant doesn’t readily produce long trailing stems, but because they tend to lose their older leaves as they grow, leaving a plant with healthy new growth at the top where new stems are sprouting from the base of the plant and healthy new growth dangling far below towards the tip of the more mature stems, but plenty of awkward-looking bare stem in between. You can “fix” this through careful pruning, but . . . it is, as mentioned, a challenge.

Older plants—more than 5 or 6 years old—tend to decline. They lack vigor and react slowly to pruning. When your plant gets to this stage, it’s time to consider restarting it from cuttings.

Multiplication: Stem cuttings are the easiest way to go and are simple to carry out.

Harvest a stem about 4 to 6 inches (10 to 15 cm) long. Remove any flowers or flower buds (indeed, it’s best to choose a stem that has neither). Also, pinch (clip off) the tip to stimulate future branching. Then remove the lowest leaves on the stem to free up an inch or two (3 à 5 cm) of bare stem where rooting can occur.

Insert the cutting into a pot of moist potting soil. (You can also start rooting the plant in water as long as you don’t leave it there more than a few weeks.) Some people like to apply rooting hormone, but that really isn’t necessary. Cover the pot with a clear plastic dome or a clear plastic bag to reduce water loss from the leaves due to evapotranspiration. Now, set the pot in a moderate lit spot under warm conditions.

Rooting occurs rapidly, especially when the cutting is taken in spring or summer. Remove the covering when new growth starts to appear, a sign the plant has rooted, and grow it as the fully independent plant that it now is!

You can also multiply this plant from seed, simply pressing the seeds into moist growing mix, and keeping the soil moist, although this is rarely done.

Toxicity: The purple passion plant is considered non-toxic, although unpalatable. It is safe for both humans and pets.

Problems: A few have been mentioned under the headings Light, Watering, Atmospheric Humidity and Temperature.

The purple passion is no more resistant to insects than other houseplants, nor is it more susceptible to them. It’s always best to inspect plants for bugs before you buy them, then to put even healthy-looking ones into isolation for the first few weeks at home. Possible pests include mealybugs, spider mites, whiteflies, aphids, scale insects and fungus gnats. Most can be controlled with sprays of insecticidal soap or neem oil.

The purple passion plant is rarely touched by diseases other than rot, at least not while growing indoors. If so, simply cut back diseased sections and the plant will usually recover on its own. If rot occurs, taking cuttings of any healthy stems may help save it.

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If you like lush purple velvet, give the purple passion plant a try. It’s found in most garden centers at least occasionally, and if not, it’s readily available on-line. The next time you go plant shopping, you know what to do!