Tradescantias: The September 2023 Houseplant of the Month

One of the pleasures of growing plants is propagating them. One day, a study will look into the chemical processes that take place in our brains when we discover that the cutting has started to put down little roots: no doubt an explosion of dopamine, one of the hormones that allows us to feel gratification (I imagine that the scientists who read this article will faint at my brazen vulgarization, but I did Social Studies in college).

Cuttings mean exchanges and gifts. Many plants are nicknamed “friendship plants”, because they multiply so quickly that we have to give them away to keep from throwing them away (my aunt, for example, almost intimidates me into taking a few babies from her Kalanchoe “Mother of Thousands”).

Although Tradescantia, which is the subject of today’s article, is not nicknamed the plants of friendship, it is possibly the easiest plants to propagate. So let’s find out more about this common plant, with its many cousins, which makes many gardeners and their neighbors happy.

Origin

The Tradescantia genus, in the Commelinaceae family, includes 85 different species of Tradescantia. Tradescantias are plants that grow in abundance in the wild, as ground cover in woodlands or in wildflower fields. Tradescantias are native to the Americas, from southern Canada to northern Argentina, but have also been introduced to other continents, where they are now naturalized (yes, another invasive plant!).

Not all Tradescantias are commonly grown indoors: to withstand the hot, dry, constant temperatures of our homes, the best varieties come from tropical or subtropical climates, such as Mexico (T. zebrina, T. fluminensis), Central America (T. spathacea) or are of horticultural origin (T. pallida), i.e. created by human cross-breeding, not discovered in nature.

Where Does the Name Come From?

Tradescantias were named in honor of John Tradescant the Younger and his father, John Tradescant the Elder, who were both plant enthusiasts; the elder being a collector, the son, a botanist. They, in turn served as head gardeners to King Charles I of England, and introduced several varieties from the Americas into the gardens under their care (including at least one Tradescantia, T. virginiana). Swedish botanist Carl von Linné honored them with the name Tradescantia.

Its common name in English is very controversial: Wandering Jew, a character from the Christian New Testament. Presumably, this name refers to the invasive nature of tradescantia’s creeping stems. It may also be called Inchplant or Spiderwort, while T. spathacea is nicknamed “Moses in a cradle” and T. pallida “Purple heart”.

If you don’t like the name Wandering Jew, there’s a recent movement that suggests replacing it with Wandering dude, which is less anti-Semitic and quite funny.

Description

All Tradescantia are herbaceous: their stems are never covered with bark. They grow vertically at first, then quickly become creeping or drooping. In the wild, Tradescantias form extensive ground cover.

Although the leaves emerge in a compact clump, they eventually spread out on their stems, which have well-defined nodes. At each node is a single, slightly lanceolate leaf, more or less long and pointed. The leaves grow stalkless, alternating on the stem.

Tradescantias can also be recognized by their ephemeral, three-petal flowers. As a four-leaf clover, you can sometimes find flowers with more petals, which are quite rare – and I guess (I decree) it’s good luck then. In good light, Tradescantia can sometimes flower indoors, but the bloom adds very little to the plant’s appeal.

Varieties

Of course, there are a few differences between the 85 species of the Tradescantia genus. Plants can be more or less succulent, with thin or leathery leaves and flexible or rigid stems. To varying degrees, their leaves may be covered with hairs, particularly in the more succulent varieties such as T. sillamontana (although this is much less apparent, T. zebrina, the purple Spiderwort, also develops small hairs when grown in good light). In some species, the stems remain upright a little longer.

The tradescantias most often grown at home are the following:

Tradescantia zebrina 

This tradescanthia is certainly the most common on the market. Easy to grow, it can be recognized by its purple leaves proudly streaked with silver. In addition to the basic form, there are cultivars where the purple covers the silver stripes (‘Purpusii’, ‘Burgundy’) and one where the silver ends up dominating the leaf (‘Silver plus’). There’s also a version whose main attraction is the vivid fuchsia color it takes on when suddenly exposed to direct outdoor sunlight (‘Red Gem’). Finally, there are cultivars of much more variable appearance, with variegated white, pink and green parts (‘Multi-color discolor’, ‘Quadricolor’).

Tradescantia fluminensis 

A plant with slender olive-green leaves, easy to grow and easy to find (often in summer arrangements of annuals). The basic olive-green form is rarely found, in favor of variegated forms in white (T. fluminensis ‘Variegata’), yellow (T. fluminensis ‘Aureovariegata’) or pink (T. fluminensis ‘Lavender’). Slightly more delicate to grow, the cultivar ‘Tricolor’ has alternating olive green, pink and white leaves, with lilac-colored undersides.

Tradescantia albiflora 

Where T. fluminensis has thinner leaves and stems than T. zebrina, you can also find a Tradescantia of similar appearance, but less modest size: T. albiflora ‘Albovittata’ (also known as T. fluminensis ‘Albovittata’), with pale green leaves variegated with white, which even offers greater tolerance to forgotten watering thanks to its longer, thicker leaves.

Tradescantia pallida

This Tradescantia can only be grown in brightly lit conditions. If placed outside in summer, it can grow very well in full sun (another classic for summer flower boxes). Fortunately, it tolerates variations in watering (but appreciates regular watering during the growing season or under intense light). There’s an all-purple version that turns green again in low light (‘Purple heart’) and a mauve version with pink stripes (‘Pink Stripes’). Synonym: Setcreasea pallida.

Tradescantia sillamontana

This inch plant has smaller leaves on thick stems. The leaves are covered with tiny white hairs, for a velvety appearance. Being more succulent in nature, this plant is less tolerant of overwatering: we prefer to wait for the soil to dry out completely before watering it again. The basic variety is often found, but a variegated version is also available (T. sillamontana ‘Variegata’).

Tradescantia cerinthoides

This plant arrived on the market a little more recently, but it quickly turned heads. Its stems and leaves are definitely succulent, making it quick to rot in the soil if overwatered. The cultivar ‘Nanouk’ (also known as ‘Bubble Gum’), with its beautiful green leaves generously topped with lilac, is the most popular houseplant. Synonyms: T. blossfeldiana, T. koernickeana Seub.

Tradescantia spathacea

An interesting variety that looks more like a rosette than a creeping stem, because it remains compact for longer (but the stem eventually reveals itself in more mature plants). It forms shoots at the base, a characteristic not present in the other species presented above. It is a slightly succulent plant, requiring fairly dry soil before watering. Easy to grow, it is available in several forms, streaked with yellow (‘Vittata’), white (T. spathacea ‘Variegata’), pink (‘Rhoéo’) and green, yellow, with mauve undersides (‘Sitara’s gold’). Its compact, upright habit makes it easy to care for in well-lit areas.

We also grow plants that look very much like tradescantias, but are in fact distant cousins. These include:

Callisia repens

Adorable little plant that passes for a dwarf tradescantia. It comes in a completely green form, a pink variegated cultivar (‘Bianca’), a chartreuse cultivar (‘Golden’) and many other versions. In terms of cultivation, callisias seem to be more temperamental than tradescantias: being semi-succulent, they can be susceptible to rot if the soil remains damp for too long, but they lose their leaves at an alarming rate as soon as they remain dry for too long. Their small size also means we have to pinch them constantly to keep the plant looking full and elegant. Otherwise, treat them like a tradescantia.

Murdannia loriformis 

This cousin is almost never identified as such; we often see it under Tradescantia ‘Silver’ or T. spathacea ‘Silver’, but, never its real name, Murdannia loriformis. The confusion is understandable: M. loriformis looks exactly like a silver version of T. spathacea. The main distinction is that Murdannia’s three-petaled flowers are found at the end of a small stem, unlike Tradescantia where the flowers grow in the leaf axils or on a much smaller stem. As far as cultivation is concerned, it’s a very easy plant to grow indoors, with the same care as Tradescantia, tolerating medium light and moderate watering without any problems.

Growing Tips for Tradescentias

Light

Although tradescantia survives in average light, it only keeps its shape and color in bright light, with a little direct sun if possible. This is particularly true the thicker the leaves of tradescantias such as T. pallida and T. sillamontana. On the other hand, direct sunlight can burn the white portions of variegated plants (particularly T. fluminensis).

Watering

Tradescantias are quite adaptable when it comes to watering. In good light – and especially since, in good light, tradescantias quickly run out of space in their pots – they can be watered generously without fear of rot. For less bushy plants, or those in medium-light situations, wait for the soil to dry out slightly. For more succulent plants, allow the potting soil to dry out completely, especially during winter when growth is limited (a good practice for most plants).

Atmospheric Humidity

Atmospheric humidity in our homes presents no problems for tradescantias (especially T. sillamontana), but most could benefit from higher humidity.

Potting soil and potting

Tradescantias are used to poor soils, so any potting soil for houseplants will do. As for repotting, good luck! Tradescantias are fast-growing, but are still drooping ground covers with brittle stems. Transplanting them is, therefore, a battle against fragile stems attached to a root ball of soil that is beginning to disintegrate piece by piece… Rather than transplanting your Tradescantia, take cuttings and start a new pot.

Fertilizers

Tradescantia can be fertilized at the indicated rate during the growing season.

Temperature

Tradescantias prefer warm, tropical temperatures. T. zebrina starts to suffer damage when temperatures drop below 13°C (55?), T. fluminensis below 10°C (50?) and the others below 7°C (45?). Of course, frost is fatal.

Interesting fact: Tradescantia often features in summer window box arrangements. Although most of the plants, we put in our flower boxes are annuals, Tradescantias are not. For more information, read this text.

Care

To stay beautiful, the plant needs at least monthly maintenance, if not more. It’s important to understand that, in nature, Tradescantias aren’t looking to make a beautiful, bushy, elegant pot, they’re looking to cover as much ground as possible: each of their nodes that touches the ground will take root and have the chance to become a second plant, ensuring the longevity of the species.

Tradescantias are fast-growing, but they pay for this with a particularly short lifespan: it’s perfectly normal for the basal leaves to dry out at an alarming rate, as the plant produces new ones at an equally impressive rate. Adopting a Tradescantia is a bit like fighting against its ground-cover nature to give the illusion that it’s a small shrub. Not an easy task! Despite all this, Tradescantias aren’t complicated. In fact, they’re quick-growing plants, and our maintenance efforts are quickly rewarded.

Pinch the Plant

The main task is to pinch the plant. By removing the longest growth point (the terminal bud), you stimulate the emergence of secondary buds. So, instead of having a single long stem, you get a stem with several growth points. Pinching is an essential principle in many plants, to give them the bushy appearance so sought-after (it’s also done in philodendrons, ficus, hypoestes and many others!

When you pinch the plant, you can also take a slightly longer section to make a cutting (see next section).

Remove Dried Leaves Frequently

Of course, it is often necessary to remove dried leaves (more often than with other plants). Stems that are too bald to be elegant must also be severely pruned. For plants with variegated foliage (in particular, T. fluminensis and its derivatives), remove the more robust, but less attractive, all-green stems, which will eventually dominate the pot. You might also consider removing the all-white or pink stems, which don’t photosynthesize and exhaust the plant.

After one or two years, most tradescantias will look like long, bald stems, sometimes breaking under their own weight. Still, there are limits to how far you can pinch! This is the time to renew the pot with fresh cuttings.

In my opinion, it’s less necessary to remove all-white or pink stems than with other plants. Firstly, they’re very pretty, but they wear out pretty quickly, so it’s not imperative to remove them – nature takes care of itself pretty quickly! Secondly, Tradescantia are quite sturdy: a few white leaves won’t stop them from growing. Finally, unless you only have one Tradescantia cutting (a very sad pot), it’s so easy to take cuttings from more balanced stems that you can instantly replace an albino stem should it die (which is rare). In my case… I leave them!

Propagation

Cutting tradescantias couldn’t be easier! The best way is to take a stem with a growing point and at least two mature leaves. Removing one of these leaves reveals a node that can be planted in water or potting soil.

In water, in good light, roots can appear as quickly as after a week. When a few small white roots have appeared, they can be placed in potting soil and the tradescantia should start growing normally a few weeks later.

If you put the cuttings directly into the potting soil, you’ll give them a better chance by placing them in a greenhouse, which you can make from a transparent plastic bag and put under bright light without direct sunlight. When the cuttings start to sprout new shoots, the greenhouse can be gradually removed.

Finally, the laidback gardener’s technique: take a cutting and plant it directly in the mother pot (unless you want to make a separate pot as a gift). Of course, some cuttings will die, but others will have time to put down some roots, even in a tightly packed pot that badly needs repotting (cf. my experience as a gardener / torturer).

Problems

Insects

• Mealybugs of all kinds, aphids, spider mites and thrips (echinothrips are particularly fond of tradescanthia).

Leaves and Stems

• Yellowed or pale leaves (especially in T. zebrina), long, stunted stems: lack of light. Spiderwort is sometimes sold as a low- or medium-light plant, but this is a lie: it will look bad if not in bright light, and will eventually die under the weight of its etiolated stems. This is true of all tradescantias except T. fluminensis, which seems to tolerate medium light a little better (but risks losing its beautiful variegation).
• Brittle stems: this is normal for the plant, but it’s best to avoid moving it too much or putting it in a busy spot.
• Soft or slimy stems: rotting of the potting soil. Start again with cuttings from stems that have not yet been eaten away by rot.
• Desiccated, threadlike stems: nothing to worry about. Sometimes, however, the stems are damaged and die, but the final leaves are still alive, living on their reserves; in this case, we find healthy-looking leaves at the end of a kind of dry “thread”. There are many causes for this: rotting of just one section of stem, mechanical damage, the weight of the stem damaging the rim of the pot, crushing by other stems… It’s very common with Tradescantia. In any case, part of the plant has died, and the healthy leaves will eventually die off unless they root quickly in the soil. Unless this happens to several stems at the same time, there’s no need to be alarmed: simply remove the cutting, which should then detach very easily.

Fingerprints After Handling

• This is quite normal. Some inch plants, such as T. pallida, are covered in bloom, which protects them from the sun (and gives them that shiny or slightly dusty appearance). When you handle the plant, you remove the bloom. It’s not harmful, but there’s no way of restoring it to its former appearance. Some insecticide treatments can also remove the bloom.

Toxicity

All parts of tradescantias are slightly toxic to humans and animals, so it’s best to keep them out of reach. The sap can also irritate the skin of those sensitive to it.

Tips for Presentation

No matter how much care you give it, tradescantia will eventually fall back (less quickly with T. spathacea, but still). Unless it’s hand-tied to a support, you have to accept its nature: tall, narrow pots or free-standing stands reduce the attention paid to the top of the pot, where the balding stems gather.

With their variegated leaves and patterns, tradescantias are a great decoration for any setting, as long as it’s in good light. Of course, as they need regular, but simple care, perfectly suited to the enthusiastic neophyte gardener who wants to learn how to pinch and cut. Once they’ve mastered these two skills, they can make their friends and neighbors very happy!