Spurges: from trendy houseplants to old classics—discover different varieties and how to care for them

Spurges (Euphorbia) is a genus that contains a massive number of species, and it is among the world’s largest plant genera. Many tropical species can be grown indoors as houseplants, but some species can be grown outdoors as perennials even in more northern climates. The Finnish nomenclature for cultivated plants names as many as 39 spurge species.

Spurges are often mistaken for cacti, but they are actually different. A key distinction is that cacti do not release white sap when their stems are cut. Spurges, by contrast, produce ample sap that can irritate the skin. That’s why you should wash your hands if any sap gets on your skin when handling spurges.

Madagascar jewel (Euphorbia leuconeura)

Care

The Madagascar jewel thrives at room temperature and requires good light, so an east- or west-facing window is ideal. Water thoroughly, then allow the soil to dry before watering again. During growing season, apply fertilizer mixed in water every two weeks. In winter, the plant may drop some leaves, so water sparingly.

If your Madagascar jewel flowers and forms seeds, you can easily grow new plants by sowing them. The plant often “shoots” its seeds once they are ripe, so you might find Madagascar jewel seedlings spontaneously popping up in nearby pots.

Crown-of-thorns (Euphorbia milii var. splendens and Euphorbia x lomii)

Care

Crown-of-thorns require plenty of light, especially if you want them to bloom. From spring to fall, place the plant in a bright east- or west-facing window. During winter, when daylight is limited, move the plant to a south-facing window.

Use cactus mix for your crown-of-thorns and water it thoroughly, allowing the top layer of soil to dry slightly between waterings. In winter, reduce watering.

To encourage flowering, fertilize your crown-of-thorns every few weeks with a liquid fertilizer, but use only half the recommended amount. Excess fertilizer will promote leaf growth at the expense of blooms.

African milk tree (Euphorbia trigona)

Care

An African milk tree may grow tall, but its root system is relatively small given its height. Therefore, avoid planting it in an overly large pot, as excess soil can retain moisture for too long and lead to rot. If your tall plant has trouble staying upright in a small pot, place it in a larger cachepot, but make sure no water collects at the bottom.

Water your African milk tree thoroughly, allowing the soil to dry between waterings. Fertilize monthly during the growing season to encourage fast growth.

The African milk tree tolerates a range of light conditions, from shade and partial shade to direct sun.

Poinsettia (Euphorbia pulcherrima)

Care

A poinsettia requires a bright, draft-free, and warm location. If you purchase one in winter, make sure it is well wrapped to protect it from the cold.

Water your poinsettia frequently in small amounts, allowing the soil surface to dry slightly between waterings. Overwatering can lead to root rot, while underwatering can cause the plant to shed its leaves.