How to Grow Oyster Plants

Purple leaved oyster plant with pink tri-lobed flower

 DianesDigitals / Flickr / CC BY 2.0

The oyster plant (Tradescantia spathacea) is known by many common names, including boat lily, purple-leaved spiderwort, and Moses-in-the-cradle. There tends to be some confusion regarding its name because there are a number of other plants with the common name of "oyster plant".

It's a popular, eye-catching, and compact house plant and can be grown outdoors in warm temperatures year-round or in the summer in temperate zones. It has glossy leaves in shades of green, purple and pink, white or pink flowers (which look identical to spiderwort), and a pleasing rosette form. There is some color variation, with some leaves showing variegation and others being solid-colored.

It's also a relatively easy-care species for those with little experience growing houseplants.

This plant is native to tropical regions, including Belize, Mexico and Guatemala. It is now naturalized in many countries and is seen frequently in parts of China and Japan. Also common in Florida and Louisiana, it has become a somewhat invasive species in hot-tropical growing areas.

Oyster plants have been used medicinally in the Philippines and in China for a variety of ailments, including dysentery, whooping cough, and respiratory illnesses. Generally, however, it is toxic to ingest and the sap can be a skin irritant, so only those with proper training should use it for medicinal purposes.

Scientific Name Tradescantia spathacea
Common Name Boat lily, oyster plant, Moses-in-the-cradle
Plant Type Annual, tropical perennial, succulent
Mature Size 6 to 12 inches
Sun Exposure Bright indirect light, outdoor shade
Soil Type Rich, well-drained
Soil pH Slightly acidic to neutral (6.1 to 7.3)
Bloom Time Summer, year-round
Flower Color White or pink
Hardiness Zones 9-10
Native Areas Belize, Guatamala, Mexico
Toxicity Toxic if ingested, sap may cause rash
Purple and gren leaved rosette leaved plants in a group in a bed edged by round stones
These oyster plants do have white variegation, but subtle tones of pale green and purple.  Forest and Kim Starr / Flickr / CC BY 2.0

Oyster Plant Care

The oyster plant is generally worry-free but needs certain conditions to thrive indoors. They like consistency of temperature, so avoid placing them near drafty windows or doors, or near a heating vent, air conditioner or radiator. They also require indirect sunlight and infrequent watering.

They're commonly available at many garden centers and nurseries, but can also be propagated easily from cuttings or side shoots. Check with your network of houseplant-loving friends to see if they can provide you with one.

Light

The oyster plant likes indirect sunlight and will even do fairly well in partial shade. This makes them useful landscaping specimens. Having them fairly near a sunny window is usually sufficient for their light needs indoors.

Soil

These plants prefer a fairly rich, very well-draining soil--sandy loam is perfect. If growing in a container, a potting mix should be sufficient.

Water

Oyster plants are drought-tolerant, and are very happy to be watered infrequently. In fact, overwatering can cause the plant to rot and die.

When the soil feels dry to the touch, water well until some water comes out the drainage holes in your container.

During its active growth season, you should water no more than once a week. The plant goes through a slower, dormant stage of growth in winter. At this point, a bit of water every two weeks will be plenty.

Temperature and Humidity

Oyster plants, being tropical, do require some humidity for their leaves to stay healthy. The easiest way to provide this is to place a tray of pebbles beneath the container. As water evaporates after watering, this will create a humid micro-climate for the plant.

Placing the plant in your bathroom, as long as there is adequate light, is also a good way to provide humidity. You can also use an electric humidifier, especially if your heating system causes the indoor air to dry out in winter.

They thrive in temperatures between 55 and 80 Fahrenheit.

Fertilizer

It's not necessary to fertilize your oyster plant, but it can help encourage new healthy growth.

Fertilizers may build up salts in the soil, which may turn leaf tips brown. If this happens, soak the plant with water and allow it to drain to flush out the soil and refresh the potting mix.

Pruning

The oyster plant doesn't require any special pruning; just deadhead any dead leaves.

Propagating Oyster Plants

The oyster plant produces new plant shoots that can be propagated as new plants. It's best to wait until they're about four inches tall to propagate.

At this point you can gently pull them from the mother plant's root system and pot them in a container.

Potting and Repotting

The root system can get quite dense so repotting the plant is necessary every two years or so. Choose a new container and add new potting soil to give it a fresh start, and water well after transplanting to lessen any stress. After that, return to an infrequent watering schedule as usual.