Aloe Barberae

Tree Aloe: Ongoing Care & Maintenance

Aloe Trees require very little ongoing care or maintenance. Watering is only necessary during establishment then, after the first year or two, only during prolonged dry spells. Pot grown specimens should be watered regularly to prevent the soil from drying out completely, but the soil should never be waterlogged as this will lead to root rot. It is worth noting that well-watered trees tend to develop larger trunks.

Aloe Trees are not particularly susceptible to pests or diseases, but it is always good practice to keep an eye out for any potential problems. The most common problems are aphids and scale insect infestations, but these are easily controlled.

While it does not need fertiliser, you can fertilise only in summer by using a succulent or slow release fertiliser that is high in potassium. Never fertilise in winter. In favourable conditions, the Aloe tree can grow up to 30 cm annually and once it is well-established, it is drought tolerant and will be low maintenance requiring no pruning or special care. If growing the tree in a container, use a large pot with sufficient drainage and keep it in a bright, sunny spot. The stems can be trimmed back to limit the height of the plant.

Tree Aloe: Propagation

The Tree Aloe is easily cultivated from seed, truncheons or stem cuttings.

Sow the seed into a free draining compost with added grit or sharp sand and place the pot in a bright position away from direct sunlight. Keep moderately moist and maintain an even temperature of around 15-18C until the seed has germinated.

Almost any stem length can be used for propagation; from 10 – 15cm stem cuttings to truncheons of up to a meter or two in length. Remove any leaves from the bottom section of the stem cutting and place it into a free draining potting mix, firming the soil gently around the stem. Some growers recommend leaving the freshly cut truncheons to dry out for a week or two before potting up, presumably to reduce the risk of rotting.

Grow the cuttings on in a warm, bright position, out of direct sunlight keeping the soil moist but not waterlogged (the stem will rot if kept too damp) until a good root system has been established.

The Aloe Barberae is a fast-growing tree that will flourish when cultivated in regions with a climate similar to that of its native home where it’s not too wet nor too cold. Weekly summer watering and added compost will benefit the tree while allowing the soil to dry between watering. However, in the colder months, water once a month (or not at all) as too much water during winter can attract pests and cause rotting. If the leaves are attacked by scale insects or aphids, it can be controlled using an oil-based spray.

The tree is sensitive to icy weather so when planting in a region prone to frost, the young plant should be protected in its first few years. Although it can tolerate moderate shade, a full sun position in a well-drained site will provide the ideal location in the garden for this timeless classic. Use a quality, loam-sandy soil with a pH that is medium to slightly acidic and ensure there is ample room for the tree to grow out to its full size. Because it has a massive stem base, it would do well to plant it away from the house or any nearby buildings.

Tree Aloe: Taxonomy and naming

Family: Asphodelaceae

Genus: Aloidendron

Species: barberae (After its discoverer, Mary Barber)

Synonyms: Aloe barberae, Aloe bainesii, Aloe bainesii var. barberae, Aloe zeyheri

Common names: Tree Aloe, South African Tree Aloe

The species has been commonly but incorrectly referred to as the Aloe bainesii, named after the well-known painter and explorer, Thomas Baines. The Aloe Barberae was in fact initially named in honour of Mary Barber, a naturalist who discovered the tree and sent plant specimens to the Royal Botanic Gardens in Kew in 1874. Although Baines had sent specimens a year earlier, the International Code of Botanical Nomenclature recognises the Aloe Barberae as the first named species.

Tree Aloe: Distribution and Habitat

The Aloe (Aloidendron) Barberae, commonly known as the South African tree aloe, makes a prominent sculptural focal point for gardens. It occurs naturally in the South African subtropical coastal forests. It is widespread along the south east coast and northwards to Mozambique and East Africa in loam, humus rich soil.

The Tree Aloe is native to coastal forests, ravines and warm well-drained valleys in the eastern regions of southern Africa. Its habitat is subtropical with an average annual rainfall of 1000 – 1500mm and a loamy, humus rich soil.

Tree Aloe: History

There seems to be much confusion with the naming of Aloidendron barberae.

This plant was first discovered in the former Transkei area of South Africa by Mary Elizabeth Barber – a naturalist, writer, painter and plant collector. It was also found, just a little later, in the Tugela River Valley area by explorer and painter Thomas Baines. Both sent specimens back to Kew and in 1874 both were named in their honour by botanist William Turner Thiselton-Dyer.

However, in 1875, Dyer realised that they were actually the same species and, because Mary Barber’s Aloe barberae was named first, it became the accepted name. Aloe bainesii is a synonym of Aloe barberae.

To complicate things further, in 2013 the original genus Aloe was re-assessed and separated out into a number of different genera. The genus Aloidendron incorporates all the Tree Aloes which are more closely related to each other than to other Aloes.

Tree Aloe: Appearance

The Tree Aloe is a large, many branched tree with a neat, rounded crown that in its native habitat can reach heights of around 18-20 meters. It has a huge trunk that can grow up to 3 meters in diameter and has rough, greyish-brown bark.

The tree is Africa’s largest aloe. It is easily identified by its smooth, grey bark, dichotomous branching, arched green foliage, and salmon coloured tubular flowers that appear during the Southern Hemisphere’s winter. In its summer habitat, sunbirds are the primary pollinators and it also attracts butterflies and hummingbirds. Once the fruits, known as capsules, ripen in late spring, the seed is naturally released and dispersed by the wind.

Each branch is topped with rosettes of long, dark green, fleshy, recurved leaves, 60 – 90 cm long and 7 – 9 cm wide. The leaf margins are edged with small, white, brown-tipped teeth, that on mature plants are 2 – 3 mm long and approximately 1 – 2.5 cm apart.

In winter, each branch produces an inflorescence, 40-60 cm long, with racemes of tubular, green tipped, rose-pink/apricot-orange flowers that measure 3 – 4cm long. The flower colour depends on the conditions in which it is grown. In its natural habitat, flowers are rose-pink in the south and apricot-orange in the north of its range.

Tree Aloe: Ecology & Conservation

Aloidendron barberae is not considered to be ‘at risk’ in the wild.

Tree Aloe seedlings often outgrow their companion plants to create a dense dark canopy under which little can grow. The flowers are attractive to bees and other pollinating insects. In their natural habitat, Tree Aloes are pollinated by sunbirds.

Tree Aloe: Uses

There are many species of Aloe that are used in the cosmetic, pharmaceutical and food industries. A popular medicinal plant, its leaves are full of a gel-like substance that purportedly contains numerous beneficial compounds. It is considered especially beneficial when applied to the skin, accelerating the healing process in wounds or burns and it may also have anti-ageing effects. It can help inhibit the growth of harmful bacteria making it a good mouthwash and for treating mouth ulcers.

For many years, the Aloe was used by traditional communities for its medicinal properties and many health products today include aloe gels, aloe drinks, capsules, and powders. Studies have proved the organic and water extracts derived from the bark, roots, and leaves exhibited positive activity against bacteria and fungus, as well as for treating gastrointestinal disorders, skin burns, and insect bites. However, it is highly advised to never topically apply or ingest the sap from your homegrown Aloe tree.