How to grow dieffenbachia (dumb cane)

Dieffenbachia is also known as the dumb cane thanks to its sap which, if ingested, can cause temporary swelling of the mouth and throat, making speaking difficult. It's therefore a good idea to keep your plant away from children and pets. Wear gloves when handling, or wash your hands afterwards. The 'cane' part of the name is derived from the fact that, in the rainforests of central and south America, where it grows naturally, the foliage tends to grow at the top, towards the light. In your home, new leaves will unfurl from the top of the central stem.

Their native habitat of dieffenbachias gives plenty of clues about their care – they need warmth, humidity and bright, dappled light.

The exact names of the varieties can be confusing and have recently changed, but the most common types that you're likely to find for sale are varieties of Dieffenbachia seguine, Dieffenbachia amoena and Dieffenbachia maculata.

How to grow dieffenbachia

Dieffenbachia do best in bright, indirect light but can tolerate light shade. Keep out of direct sun. Water when the soil starts to become slightly dry at the top. Dieffenbachia thrives in warm temperatures, ideally 18-24°C. Avoid draughts and fluctuating temperatures. Mist regularly, or keep on a tray of moist pebbles.

Dieffenbachia: jump links

• Planting a dieffenbachia
• Caring for dieffenbachia
• Propagating dieffenbachia
• Growing dieffenbachia: problem-solving
• Buying dieffenbachia
• Best dieffenbachia plants to grow

Where to grow dieffenbachia

Dieffenbachias are a little fussy – they need a warm room that's around 16-24°C, although they can tolerate temperatures as low as 10°C for a short time. They suffer with cold draughts or dry air. Grow in a bright spot but avoid direct sunshine.

How to plant a dieffenbachia

Plant into a pot that is the same size or a little larger than the rootball. Use soil-based compost.

How to care for dieffenbachia

From spring to autumn, water whenever the top few centimetres of compost become dry. Let any excess drain away. Water sparingly in winter. Mist the plant a few times a week, or place on a tray of moist pebbles. Rotate your plant to keep it growing evenly. Wipe the leaves occasionally to keep them dust free. Feed once a month with a weak liquid feed.

Repot if necessary in spring, every two or three years, once the plant has become rootbound. Plant into a slightly larger pot.

How to propagate dieffenbachia

The easiest way to propagate dieffenbachia is by dividing it. A good time to do this is when you repot in spring. Simply pull the plant apart gently, making sure each piece has some roots, and plant each new plant in its own pot.

Growing dieffenbachia: common problems

Pale, washed out leaves and poor growth could be due to low light levels – move your plant to a brighter spot.

Dropping lower leaves, wilting, curling or yellowing leaves could be due to low temperatures – move your plant to a warmer spot.

Direct sunlight will scorch the leaves, creating brown patches.

Drooping leaves can be caused by under or overwatering, so check your watering regime and adjust accordingly.

Crinkly or crispy leaves could be due to lack of water.

Brown edges or tips could be due to compost or air that is too dry, or uneven watering. You might have also given your plant too much fertiliser.

It's normal for a dieffenbachia to become tall and leggy over time, losing its lower leaves. You can simply cut the plant down to its desired height - it should resprout from the point where it was cut. You can also then replant the crown into its own pot, which should root and form a new plant. Alternatively, cut the plant down to around 10cm tall and wait for it to resprout.

Mealybugs can be a problem on dieffenbachia – look out for insects that look like white, fluffy blobs on the undersides of leaves. Wipe them off with a damp cloth or cotton bud that has been soaked in an insecticide that contains fatty acids or plant oils.

If the leaves and stems of your plant are covered in fine webbing, this could be spider mites. The upper surface of the leaf may be mottled, while mites and eggs can be seen with a magnifying glass on the undersides of leaves. Improve air circulation around the plant and boost humidity by misting or standing on a tray of moist pebbles. Treat with a spray containing fatty acid or plant oils.

Raised brown spots on the leaves could be scale insect. Wipe them off with a damp cloth or cotton bud that has been soaked in an insecticide that contains fatty acids or plant oils.

Varieties of dieffenbachia to grow

• Dieffenbachia 'Camilla' - lush, apple green leaves with a creamy white splash in the centre.
  Height x Spread: 80cm x 50cm
• Dieffenbachia 'Reflector' – emerald green foliage with lime green flecks that seem to glow, hence the name.
  H x S: 1.2m x 50cm
• Dieffenbachia 'Tropic Snow' – emerald green leaves with distinctive cream markings.
  H x S: 1.2m x 50cm