Archontophoenix maxima - Walsh River Palm

The Archontophoenix maxima, better known as the Royal Palm, is the largest representative of the genus Archontophoenix. It differs from its close relative A. cunninghamiana by its larger size, a more massive and regularly ringed "trunk," and larger, more upright fronds that are a bright green with a touch of silver-grey. The summer flowering and fruiting of this magnificent subspecies are even more decorative. Slightly hardier than its cousin, Archontophoenix maxima can only be acclimated to open ground in mild, frost-free climates. Elsewhere, it should be planted in a large pot that is sheltered in a greenhouse or spacious conservatory over winter. It is a graceful and luxuriant plant that thrives in cool, deep, and humus-rich soil.

Archontophoenix maxima is endemic to the Australian state of Queensland, where it grows to between 8 and 12m (26 ft and 39 ft) above sea level. This beautiful palm develops a single, smooth, grey trunk, marked by rings that are remnants of old petioles. In its natural habitat, it can reach a height of 30m (98ft) with a trunk diameter of 30 cm (11.8 in), but it will remain much smaller in European latitudes, and even smaller in a container where it will not exceed 3 metres (9 feet 10 inches) in height. At the top of the trunk, it forms a crown formed of large palmate, slightly arched leaves, with a large number of light green, tough, and glossy leaflets or pinnules, with a light grey-green underside. Each leaf is erect at the base but slightly drooping at the tip, carried by a long petiole. Flowering occurs in summer, in the form of large, dense, branched inflorescences that emerge from under the crown of the leaves. There are male and female flowers, borne on separate inflorescences. They are massive, measuring up to 1.5m (5 ft) in length, bearing white to purplish flowers. These small flowers are followed by inedible but highly decorative oval, bright red fruit when ripe, measuring 1 cm (0.4 in) in diameter.

When planted in open ground, this palm deserves a spot as a standalone plant on a lawn or in front of a large shrubbery that will protect it from strong winds and intense sunlight. It also forms elegant rows in mild climates, including coastal areas. It requires space to fully showcase its beauty and grows quickly if provided with ample water and nutrients. It thrives in container cultivation and makes a superb indoor plant for spacious, well-lit entrances, conservatories, and temperate greenhouses. It can sometimes be challenging to find suitable companions for this palm due to its strong personality. Reserve a corner by a swimming pool and plant small evergreen shrubs such as bushy sage or teucrium, which are simple and floriferous, at its base. Phormiums, with their graphic, minimalist, and colorful foliage, precise and geometric agaves, the almost metallic Astelia chathamica, the orange autumn foliage of Hakonechloa macra Aureola, and the purple and delicate Verbena bonariensis will all accompany it in a border that is both exotic and easy to maintain.