Purple Heart

How to care for Purple Heart

Light

Tradescantia pallida produces its most intense purple pigmentation under bright light conditions. A position near a south- or west-facing window is ideal indoors. It will tolerate some direct sun, which actually deepens the leaf colour, though prolonged harsh midday sun through glass may scorch the foliage. In low light the leaves become greener and the stems etiolate, losing the compact, attractive habit that makes the plant desirable.

Watering

Water moderately throughout the growing season, allowing the top 2 cm of compost to dry out before watering again. The stems are semi-succulent and store some moisture, making the plant fairly tolerant of short dry periods. Overwatering is the most common error; waterlogged compost leads to stem rot relatively quickly. Reduce watering considerably in autumn and winter when growth slows. Always use room-temperature water and avoid leaving the pot standing in water.

Soil and potting

A free-draining compost is essential. A standard multipurpose potting compost mixed with approximately 20 to 30 per cent perlite or coarse horticultural grit works well. Good drainage prevents the root rot to which this plant is susceptible when grown in heavy or moisture-retentive media. A slightly acidic to neutral pH in the range of 6.0 to 7.0 is suitable.

Feeding

Apply a balanced, water-soluble fertiliser at half strength once a month during the active growing season from spring through to late summer. Excessive feeding, particularly with high-nitrogen formulations, can promote lush green growth at the expense of the characteristic purple colouration. Do not feed during autumn and winter when the plant is resting.

Humidity and temperature

Tradescantia pallida is tolerant of average household humidity levels and does not require misting or a humidifier. It performs best at temperatures between 15 and 30 C and is not frost-hardy; temperatures below around 10 C can cause damage. It should be kept away from cold draughts, poorly insulated windows in winter, and sudden temperature fluctuations, all of which can cause leaf tip browning.

Repotting

Repot in spring every one to two years, or when the plant becomes visibly root-bound. Move up only one pot size at a time, as a pot that is too large increases the risk of waterlogging. Because T. pallida grows quickly and the stems become leggy with age, many growers find it more effective to propagate new cuttings rather than continually repotting ageing plants. Use fresh, free-draining compost when repotting.

Pruning

Regular pinching back of stem tips encourages a bushier, more compact habit and prevents the plant from becoming straggly. Pruning can be done at any time during the growing season. Cut or pinch just above a leaf node. Leggy stems can be cut back hard and the plant will generally regenerate from the base. The removed cuttings are readily used for propagation. Remove any dead or yellowing leaves promptly to maintain appearance and hygiene.

Is Purple Heart toxic?

Common problems

How to propagate

Stem cuttings in water

Take a cutting of 10 to 15 cm with at least two or three nodes, remove the lower leaves, and place in a glass of water in a bright location. Roots typically appear within one to two weeks, after which the cutting can be potted into compost.

Stem cuttings in compost

Take cuttings as above, allow the cut end to callous for a few hours, then insert directly into moist, free-draining compost. Keep the compost barely moist and place in bright indirect light; roots usually establish within two to three weeks.

Division

When repotting a large, multi-stemmed plant, the root ball can be carefully divided into sections, each with healthy stems and roots, and each section potted individually. This is less commonly used than cuttings but is effective when the plant has formed a substantial clump.

Where Purple Heart comes from

Native to eastern Mexico, Gulf Coast region of Mexico, Tamaulipas, Veracruz, San Luis Potosí.

Story and origins

The genus name Tradescantia honours John Tradescant the Elder (c. 1570 to 1638) and his son John Tradescant the Younger (1608 to 1662), both of whom served as royal gardeners in England and were influential plant collectors who introduced numerous species to cultivation in Britain. The specific epithet pallida is Latin for 'pale', which is somewhat counterintuitive given the plant's vivid purple colouring; it likely refers to the pale pink flowers rather than the foliage. The cultivar name 'Purpurea' is simply Latin for 'purple', describing the dominant characteristic of the most common form in cultivation.

Tradescantia pallida was first formally described by the American botanist Joseph Nelson Rose in 1911, based on specimens collected from the Gulf Coast region of eastern Mexico, particularly Tamaulipas and neighbouring states. It was originally classified within the genus Setcreasea before being moved to Tradescantia by D.R. Hunt in 1975 as botanical understanding of the Commelinaceae family advanced. The plant gained popularity as an ornamental during the twentieth century and spread into cultivation across warm temperate and subtropical regions worldwide. In parts of Central America and the southern United States it became naturalised outside its native range. Its bold colouration made it a popular choice in bedding displays and hanging baskets throughout the twentieth century, and it has remained a consistently popular houseplant into the present day.

Varieties to know

Tradescantia pallida 'Purpurea'

The most widely grown cultivar, with uniformly deep purple foliage throughout the entire plant. It is effectively the standard form sold under the common name Purple Heart.

Tradescantia pallida 'Pink Stripe'

Features purple leaves with irregular longitudinal pink and pale cream striping, giving a more variegated appearance than the straight species.

Tradescantia pallida 'Pale Puma'

A cultivar with slightly more muted, silvery-purple foliage tones, sometimes described as having a pale or dusty hue compared to 'Purpurea'.

Fun facts

• The deep purple pigmentation in T. pallida is due to anthocyanin pigments, which are produced in greater quantities under high light intensity, explaining why brighter conditions produce more vivid colouration.
• Tradescantia pallida has been studied in scientific research as a bioassay plant: pollen from its staminal hairs can mutate from blue to pink in the presence of certain mutagens, making it a useful indicator of environmental pollution.
• In parts of the southern United States, T. pallida is considered an invasive ornamental plant when grown outdoors, spreading readily along roadsides and disturbed ground due to its ability to root from fallen stem fragments.
• Despite its common name, T. pallida is not closely related to true spiderworts in the garden sense; the name 'spiderwort' is shared loosely across the Tradescantia genus.
• The flowers of T. pallida are short-lived, typically lasting only a single day, but are produced continuously throughout the warmer months.

Purple Heart FAQ