Rubber plant

Light and exposure

The rubber plant wants bright light, without scorching direct sun. A spot near an east or west facing window, or slightly back from a south facing window, suits it. The variegated varieties (Tineke, Ruby) need more light than the dark green type to keep their colours, but never full summer sun.

In insufficient light, the plant stretches, the space between the leaves lengthens and the base thins out. In our winter light, weak from November to February, move the pot closer to a bright window and turn it a quarter turn a week so it grows straight.

Watering

Let the top two to three centimetres of substrate dry out before watering again, roughly once a week in spring and summer, then every ten to fifteen days in winter. The rubber plant copes far better with a slight lapse than with excess water.

Always empty the saucer: roots left soaking rot, and that is the first cause of loss of the lower leaves. In winter, when the plant slows down because of the weak light, cut back the watering sharply. Leaves that yellow and fall in series almost always signal watering that is too generous, not a lack of water.

Soil and repotting

A quality potting soil for green plants, lightened with a handful of perlite or a little bark for drainage, works very well. The pot must have holes, that is non negotiable for this plant that is sensitive to standing water.

Repot in spring every two or three years, or when the roots spill out of the drainage holes, into a pot only slightly larger. A pot that is too big keeps the soil damp too long and rots the roots. On a large specimen that is hard to repot, simply replace the top few centimetres of soil each spring.

Temperature and humidity

The rubber plant is happy between 16 and 24 degrees. Below 12 degrees it suffers and may lose its leaves. It tolerates no frost. Keep it away from cold draughts from doors and single glazed windows, as well as from hot radiators that dry out its foliage.

The sensitive Belgian point is winter: the plant does not like cold snaps, but it also suffers from the air dried out by central heating from November to March. Regularly dusted foliage and a little humidity in the air help it get through the season. Above all, avoid leaving it in a cool, damp room and watering it as if it were summer.

Pruning and upkeep

Pruning is done in spring. Cut the top of the main stem above a leaf to stop the plant growing taller and force it to branch out. The plant then grows back in several branches below the cut. Wear gloves, because the milky sap flows abundantly and irritates the skin.

Regularly wipe the large leaves with a damp cloth: dust builds up on them quickly and blocks the light, already scarce in winter. Clean, shiny foliage captures the little available light better and stays healthy.

Pests and diseases

In winter, in dry air, watch out for scale insects (mealybugs and armoured scale) that settle along the veins and in the leaf axils, and for red spider mites (Tetranychus urticae) under the foliage. Remove scale insects with cotton wool soaked in diluted methylated spirit and raise the room humidity against the mites.

The drop of the lower leaves is the most common trouble: it comes from excess water, a cold snap or a sudden change of location. The rubber plant does not like being moved often. Find it a good spot and let it settle in.

Propagation

Tip cuttings are taken in spring or summer. Cut a section of stem with two or three leaves, let the sap dry for a few minutes, then plant the cutting in a light, moist mix and cover with a plastic bag to keep the humidity. Rooting takes several weeks of patience.

For a specimen bare at the base, air layering gives better results: notch the stem, wrap the wound in moist moss held by plastic film, and cut below the roots once they have grown well, often after one to two months.

Toxicity

The milky sap contains latex that irritates the skin and mucous membranes, and causes digestive upset if a leaf is chewed. Keep the plant away from cats, dogs and young children, and wear gloves to prune it.

Month-by-month care calendar

Green Hub tips

• Wear gloves to prune: the milky sap irritates the skin and stains clothes.
• The rubber plant hates being moved. Find it a good bright spot and let it settle in without constantly shifting it.
• Lower leaves yellowing and falling in winter: it is almost always excess water. Let the soil dry out more.
• Cut the top in spring to force the plant to branch out rather than grow into a single bare stem.