PLNTversePLNTverse
Plants › Palms & cycads

Alexandra palm (Archontophoenix alexandrae)

Archontophoenix alexandrae is a tall, evergreen, perennial palm with a single trunk and an upright, columnar habit.

LightOutdoors it can grow in full sun to partial shade, although partial shade is recommended, particularly to help avoid leaf scorch; greenhouse plants can be given bright, filtered light.
WaterWater moderately during the growing period and keep the soil moist but well drained; watering after the surface soil dries is also recommended, with less water in winter so the growing medium remains only slightly moist.
HumidityIt is generally reported to prefer moderate humidity.
TemperatureHorticultural sources provide hardiness classifications for Archontophoenix alexandrae, without a numerical classification stated here. It is generally considered frost tender; keep above freezing.
Track your Alexandra palm in the PLNTverse app
Alexandra palm illustration

Overview

Archontophoenix alexandrae is a tall, evergreen, perennial palm with a single trunk and an upright, columnar habit.

Origin and habitat

Archontophoenix alexandrae is native to eastern Queensland, Australia, with more detailed accounts placing its range from northeastern to central-eastern Queensland, extending from the Melville Range area of Cape York Peninsula south to beyond Gladstone. Sources differ on habitat details, but describe it as native to tropical rainforest, especially lowland riverine rainforest and areas near waterways and swamps, including sites subject to severe flooding during heavy rain, from sea level into higher elevations. It favors warm, frost-free tropical to subtropical climates and can also be cultivated in cooler frost-free areas outside the tropics.

Characteristics

Sources differ on mature height, placing it at about 2000–3000 cm, while a single source reports a mature spread of about 400–800 cm. It grows rapidly and bears large, arching pinnate leaves with numerous narrow leaflets; the upper leaflet surfaces are green, the undersides gray to silvery gray, and the leaves are often slightly twisted sideways. Large panicles emerge near the base of the crownshaft, bearing small cream-white to yellow flowers, and sources differ on flowering season, describing flowering as irregular throughout the year or in summer. The fruit is ovoid to nearly spherical with a persistent calyx, changing from green when immature to bright red or pinkish red when mature, and contains a single seed.

Light

Outdoors it can grow in full sun to partial shade, although partial shade is recommended, particularly to help avoid leaf scorch; greenhouse plants can be given bright, filtered light.

Watering

Water moderately during the growing period and keep the soil moist but well drained; watering after the surface soil dries is also recommended, with less water in winter so the growing medium remains only slightly moist.

Humidity and airflow

It is generally reported to prefer moderate humidity.

Temperature and dormancy

Horticultural sources provide hardiness classifications for Archontophoenix alexandrae, without a numerical classification stated here. It is generally considered frost tender; keep above freezing.

Growing medium and mounting

It prefers fertile, moist but well-drained soil; horticultural sources list loam, sandy and chalky soils as suitable, along with acidic, neutral or alkaline conditions.

Feeding

Liquid fertilizer can be applied monthly during the growing period, and fertilizing and mulching are also described as supporting good growth.

Propagation

Propagate by seed; spring sowing with a moist growing medium and humid air is recommended, and fresh seed is also described as readily germinating.

Common problems

In greenhouse conditions, it is reported to be susceptible to red spider mites and generally to have few disease problems. Excessively strong outdoor light is reported to cause leaf scorch, so partial shade is recommended. It is sensitive to frost, should be kept away from freezing conditions, and is suited to frost-free climates.

Identification

Archontophoenix alexandrae has a tall, straight, smooth trunk with conspicuous ring-shaped leaf scars and a base that is often slightly swollen; the trunk is topped by a smooth green crownshaft, while the large pinnate leaves have silvery-gray leaflet undersides and the mature fruit is bright red.

Photos

Archontophoenix alexandrae
📷 Forest & Kim Starr · CC BY-SA 3.0 · source
Archontophoenix alexandrae
📷 dhfischer, some rights reserved (CC BY), uploaded by dhfisch · CC BY · source
Archontophoenix alexandrae
📷 dhfischer, some rights reserved (CC BY), uploaded by dhfisch · CC BY · source

Sources