Umbrella tree

Identification and origin

Heptapleurum actinophyllum, long sold as Schefflera actinophylla or Brassaia actinophylla, belongs to the Araliaceae, the ivy family. It is native to the wet tropics of northern Australia (Queensland and the Northern Territory) and southern New Guinea. In the wild it is a tree, often multi-trunked, up to 39.5 ft tall, whose seedlings frequently start life as epiphytes on another tree. The name “schefflera” honors the botanist J. C. Scheffler, and the epithet actinophyllum refers to the rayed arrangement of the leaflets.

In a pot it grows fast and usually reaches 4–8 ft; it is often sold at 2–3 ft and can outgrow that range if left unpruned. The alternate leaves are palmately compound: each carries, at the end of a stalk, five to eighteen stalked leaflets arranged in a circle, like the ribs of an umbrella. Young plants have only three to five. The leaflets, oblong, thick, and glossy, dark green above and paler below, measure 4–6 in indoors and up to 12 in outdoors.

In full sun in tropical climates, it produces long, radiating flower spikes of 2–4 ft above the foliage, covered in small red flowers: hence the name “octopus tree.” Fleshy fruits follow, purplish red to black. Indoors it rarely blooms. The compact cultivar ‘Amate’ stays dense even in moderate light and better resists leaf spot and spider mites; there is also a variegated form, ‘Variegata’.

Light

Give it medium to bright light, ideally bright light filtered through a sheer curtain, near a well-lit window. It enjoys sun, but protect it from hot afternoon sun through glass, which can scorch the foliage.

Poor light shows quickly: yellowing leaves, weak, stretched stems, and leaf drop. In a dimmer spot, cut back on fertilizer as well, since the plant grows less.

Watering

Water thoroughly, then wait until the top 1 in of the mix is dry before watering again. Never leave the pot standing in water in its saucer. If you can, use rainwater or filtered water.

Watch the foliage: too little water makes leaves drop, but so does too much, and constantly wet mix encourages root rot, bacterial leaf spot, and soft rot. The umbrella tree likes high humidity; very dry air during the heating season can also cause leaf drop.

Potting mix

A general-purpose houseplant mix works, as long as it drains quickly: a mix that stays soggy or watering too often leads to root rot. The plant likes rich, moist, well-drained soil with an acidic to neutral pH.

During active growth, feed regularly with a water-soluble or slow-release houseplant fertilizer, following the label rates. Feed less often if the plant gets little light.

Temperature

By day it prefers 64–75 °F, and at night at least 61 °F; it handles heat well, up to about 90 °F. Do not let it drop below 50 °F: a chill shows up a few days later as dead patches on the leaves. Keep it away from heating vents, radiators, open windows, air conditioners, and hot or cold air currents.

It is grown in the ground only in USDA zones 10a to 12b. Elsewhere, it can spend the summer outdoors in a container in a sheltered spot, but it must come back inside for winter. It has low tolerance for salt spray. In tropical climates it can reseed and become invasive: it is listed as an invasive exotic in central and south Florida.

Repotting

Repot whenever the plant becomes crowded in its pot, at any time of year, into fresh, fast-draining all-purpose mix. The pot needs drainage holes: mix that stays soggy rots the roots.

Pruning

Pruning is not essential, but it keeps this vigorous plant at a manageable height. To keep it compact, cut a stem just above a leaf; it can also be cut back in winter. Over time, the lower stems tend to lose their leaves. The wood breaks easily, so handle the plant with care. Wear gloves, since the sap can irritate skin.

Propagation

The umbrella tree is propagated by seed, stem cuttings, or air layering. It roots slowly and needs high humidity and bright light to do so.

For cuttings, take a 4–6 in tip from a vigorous shoot, cut just below a node with a clean blade. Strip the leaves from the lower half, dip the base in rooting hormone, and insert it 1–2 in deep in an equal mix of perlite or sand and peat moss. Cover with a clear plastic bag that does not touch the leaves, keep the medium moist, and keep the setup out of direct sun.

For air layering, remove the leaves a few inches on each side of the chosen point on the stem, then strip away a ring of bark 1–1 in wide. Apply rooting hormone, wrap the wound in moist sphagnum moss, and enclose it in clear plastic tied at both ends. Roots usually appear after a month or more. Then cut below the roots, pot the new plant, and keep it under a clear bag for about a week.

Common problems

• Leaf drop: overwatering or underwatering, very dry air, chilling, or prolonged low light.
• Yellow leaves and spindly stems: not enough light.
• Dead patches on leaves: cold exposure a few days earlier.
• Root rot, bacterial leaf spot, soft rot: mix that is too wet or drains poorly.
• Pests: mealybugs and scale insects, spider mites (especially indoors), aphids, and thrips. Check leaf undersides often; honeydew from scale leads to sooty mold.

The same symptom can have several causes: always look at light, watering, temperature, and humidity before acting.

Toxicity

Toxic to dogs and cats, as well as to horses and young children. All parts of the plant contain terpenoids, saponins, and insoluble calcium oxalate crystals. Eating it causes irritation and swelling of the mouth, tongue, and lips, excessive drooling, vomiting, difficulty swallowing, and sometimes diarrhea; in pets, the most common signs are mild vomiting and diarrhea. The sap can cause contact dermatitis. If any part is swallowed, contact your veterinarian or a poison control center.