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Care information

Skip to: Light and colour // Water and food // Potting and pruning // Propagating

Care is broadly the same for keeping most tropical Commelinaceae as houseplants. This basic guide is a summary of how to care for them in general, and will also include some specific tips for common groups within the family.

Light and colour

This requirement is fairly variable across the family, but most species can tolerate quite a range of light levels. Overall when growing as houseplants, it’s almost impossible to provide too much light – even the sunniest place indoors is more like shade outside.

Many species and cultivars develop anthocyanins, which are red or purple pigments that act as sun protection for the plant. They combine with the underlying chlorophyll (green pigment) of the leaf to make a huge range of colours. If the underlying leaf is dark green, anthocyanins can make it rich purple (like Tradescantia pallida ‘Purpurea’ or Tradescantia zebrina ‘Violet Hill’). If the leaf has variegated white or yellow parts, anthocyanins can turn those areas bright pink (like Tradescantia mundula ‘Lisa’ or Tradescantia ‘Maiden’s Blush’).

The plant changes the amount of anthocyanins in the leaves in response to the amount of light it needs to protect itself from. This means that if the plant is in higher light, it will show its red or purple colours more strongly than in lower light. So if you’re growing any cultivar which has these colours, you can influence them by giving it different light levels. If you want the plant to show brighter or stronger pink and purple colours, give it higher light. If you want it to be more green or yellow, give it less light. With some experience, you can even use these plants as indicators of the light level, by watching how their colour changes in different locations.

If a plant has too much light to cope with, its growth will generally slow down and become stunted. The leaves might become scorched with brown or crispy spots, and start to curl up or wilt. If a plant doesn’t have enough light, its growth will become etiolated (“leggy”) – the stems grow very long and thin with small leaves.

In general, plain-green creeping plants are the most likely to tolerate low light without major problems. Cultivars with delicate white- or pink-variegated leaves are at the most risk of scorching in direct light, although they can still adapt to it given plenty of time. Of the popular cultivated types, species from Tradescantia subgenus Setcreasea (like T. pallida and T. sillamontana) tend to be the most demanding of direct sun, and will become very etiolated and pale in anything less than the brightest light.

Tradescantia pallida 'Purple Pixie' small plant.
Tradescantia pallida ‘Purple Pixie’

Water and food

People are often surprised to learn that most Commelinaceae species are somewhat succulent. They have the ability to store water in their stems and sometimes leaves, which makes them quite tolerant of drought. But they are not quite as prone to rot as more extremely adapted succulents like cacti. In general when growing in containers, you should let the soil mostly dry out in between waterings. If you stick your finger into the soil and it still feels moist or sticky, it doesn’t need watering yet!

Because they are drought tolerant, they don’t show very obvious signs when they’re thirsty. But there are subtle hints to look out for. The leaf surface becomes more smooth and shiny, the leaves themselves become slightly thinner and papery, and colours become dull and greyish. This picture shows a comparison of Tradescantia mundula ‘Green Hill’ when thirsty and when well-hydrated.

Two stems of Tradescantia mundula 'Green Hill', one is thirsty showing a greyish colour and glossy texture, the other is hydrated and looks bright green with a satiny texture.

They won’t show any signs at all if they’re too well-hydrated. It won’t be apparent until the roots have rotted and the plant starts to die. That’s why if you’re in any doubt at all, it’s much safer to water less often rather than more. If you’re not sure whether the plant needs water, just wait a couple more days! Eventually it will start to show signs that you can recognise, and then it will recover very quickly once it’s rehydrated.

In general, plants with thicker, tougher-feeling leaves are the most tolerant of drought – particularly if the leaves are also covered in hair. Tradescantia sillamontana with its “cobweb” furry leaves can be treated pretty much like a succulent. Whereas plants with thinner or papery leaves like Tradescantia fluminensis need water a little more often.

The need for extra fertiliser will depend on the potting mix a plant is in – if it contains slow-release nutrients then they won’t need supplemental nutrients unless they’ve been in the same soil for over a year. If the potting mix doesn’t have any nutrients, or only comes with a few weeks’ or months’ supply, then they’ll need periodic feeding with any standard fertiliser just like other container plants. A hungry plant will slow down its growth, and leaves will start to become faded and yellow.

Potting and pruning

Although their roots grow and spread very quickly, Commelinaceae don’t generally suffer much from lack of root space. The main problem rootbound plants have is that there isn’t enough soil to hold onto water for a long time, so they become easily dehydrated. But semi-succulents are great at storing water, so that doesn’t cause much of an issue.

Different species have different growth habits, but they are almost universally creeping plants to one degree or another. In the wild their stems spread along the ground, rooting as they go. Transfer that growth habit to a container, and you have a plant which trails out of its pot with hanging stems. Some people prop up long stems with canes or trellis, but they are not naturally climbing plants so this is really creating an artificial state – without support any long parts will eventually lean over and start to trail.

Because they have developed to crawl along the floor, they aren’t adapted well to having stems that grow a very long way from the roots – either hanging out of a pot or being propped upwards. Long parts will progressively lose their lower leaves, which people often find unattractive. The stems are also very brittle and ultimately they are likely to break or fall off once they get long. This isn’t a sign of any problem, it’s simply a natural response for a plant which wants to maintain constant contact with the ground and grow roots all the way along.

To slow down this progression of bare lower stems and broken pieces, prune the growing stems as often as possible – the plant will immediately start making new branches. Once a plant becomes very old and straggly, it’s generally easier to “restart” than to try to repot. Cut the healthy ends from all the stems, then discard the whole base and rootball, and pot the cuttings back into fresh soil (or propagate them in any other way).

Tradescantia chrysophylla ‘Baby Bunny Bellies’

Propagating

Commelianceae plants – especially tradescantias – are almost legendarily easy to propagate from cuttings. A short piece of stem with a single leaf has the ability to grow roots and form a whole new plant, just by laying on bare ground. In fact, this is why their stems are so brittle – they’ve evolved so that pieces will break off at the slightest touch and root wherever they land! In some warm locations, tradescantias are considered invasive because of how easily they spread.

Everyone has their own preferred method for propagating. Some people like to put cuttings in water to watch the roots grow before potting them up. Other people lay cut stems flat on the surface of soil to mimic their wild behaviour. Or poke a vertical hole into the soil and push the bottom part of the stem down into it. The truth is, it’s difficult to go wrong – they practically propagate themselves!

Because it’s so easy to propagate cuttings in soil, it can be done alongside pruning in the same process. Cut the ends of longer stems, and stick them straight back into the same pot, for a double-action approach to making a more bushy plant.

For delicate or struggling cuttings, increased humidity will improve the success rate. Put a clear bag over the top of the pot, or put the entire pot inside an airtight container like a plastic box. This will reduce the amount of water the plant loses through its leaves, so it doesn’t have a constant battle with dehydration before it’s formed enough roots to drink with.