Aloe arborescens (Krantz Aloe, Kransaalwyn) is probably the most widely grown of all the Aloes. A succulent shrub typically grows up to 2 metres tall with a 3 metre spread, it is one of the most free-flowering and showiest of all the Aloe species. It can be used effectively as an informal hedge or as a feature plant on its own.
Family: ASPHODELACEAE (Aloe Family)
Alternatively under Aloaceae, previously under Liliaceae (in the broad sense).
Name Derivation:
- Aloe – Uncertain origin, may be of Greek, Arabic, Hebrew or Sanskrit origin.
- arborescens – tree-like, from arbor (Latin) for tree.
Common Names:
Krantz aloe, mountain bush aloe (Z) (Eng), kransaalwyn (Afr), sekgopha (Nso), imbovane (Swa), tshikhopha (Ven), unomaweni (Xho) and umhlabana (Zul).
FSA Number: 28.1 Zim Number: 17
Branched from close to the ground, the long fleshy leaves are spirally arranged.
Features of Aloe arborescens
Form: A much-branched, succulent shrub.
Size: 1 – 2 m (up to 4 m) by 1 – 3 m.
Stem and Bark:
- Branched from close to the ground.
- Much branched shrub.
- The dead leaves remain attached to the stems for a long time.
- Bark is light grey or brown.
Thorns:
- Soft teeth along the leaf margins.
Foliage:
- Evergreen.
- Simple, succulent leaves are long (to 70 cm), narrow (7 – 8 cm), tapering to the apex.
- The leaves are arranged in spreading rosettes at the end of branches.
- Leaves are usually a little sickle-shaped
- The leaf margin is lined with conspicuous pale teeth.
- Dull greyish-green to blue-green may turn reddish when exposed to cold or too much sun.
- Old, dead leaves remain on the plant below the rosette.
Aloe arborescens is an interesting structual plant that can be used to effect in a garden even when it is not flowering.
The long racemes of Aloe arborescens are typically simple and have many flowers.
Flowers:
- Individual flowers are tubular and up to 4 cm long.
- Borne in clusters of many flowers at the end of a raceme that may be up to 80 cm long.
- The racemes are mostly simple but some may be branched 2 or even 3 times.
- Usually there is one raceme per rosette of leaves, but can have up to 4 on healthy mature plants.
- Plants in full flower can be very showy.
Colour: Scarlet, orange, yellow or, very rarely, white.
Flowering Months: May – Jul.
Fragrance: Not fragrant.
Fruit:
- A capsule with 3 compartments that contain many slightly winged seeds.
- Green ripening to light brown.
Cultivating Aloe arborescens
In the Garden:
- Add valuable, bright colour to gardens in winter when not much else is flowering.
- Plants are attractive even when not in flower, so a good focal plant in a large rockery.
- Often used as a very showy, informal hedge.
- Water-wise plant.
- Can be used close to walls and paving as the roots are not aggressive.
- An essential plant in any ‘wildlife garden’, attracting a variety of birds, bees and other insects.
- Fast growing and plants will start flowering while still quite young.
Soil Needs: Well drained soils rich with compost.
Care:
- A low maintenance plant.
- Feed with organic fertilizer and mulch with compost.
- Protect young plants against the cold in winter.
- Do not appear to be prone to Snout Beetle attack.
Aloe arborescens must be amongst the most showy of all garden plants when flowering.
The yellow flowered form of this Aloe used to be rare, but is now quite common.
Besides being so beautiful in flower, Aloe arborescens flowers attract many birds.
Cold Hardiness: Hardy.
Water Requirements:
- Drought hardy, but likes regular water, particularly during summer.
- Water-wise.
Light Requirements: Full sun or partial shade.
Space Requirements: Plant 2 – 2.5m apart.
Roots: The roots are not aggressive.
Ecology of Aloe Arborescens
Birds:
- Sunbirds and many other birds will visit the flowers for the nectar.
- Insect-eating birds are attracted to the insects that hide in the dried leaves.
Bees:
- A valuable source of pollen and nectar during winter.
Butterflies and other Insects:
- Not a known host plant to butterfly or moth larvae.
Medicinal:
- A pulp made from leaves is effectively used to treat against X-ray burns.
- Used by Zulu sangomas during childbirth.
Poisonous: Not poisonous.
A honey bee collecting pollen from an Aloe arborescens flower
The fleshy leaves of Aloe arborecens are edged with soft, pale teeth.
Notes of interest:
- This is almost certainly the most widely grown Aloe species, grown in gardens in most warm areas of the world.
- Aloe arborescens is often used in rural areas as a hedge to protect crops and stock
- Considered by some peoples as a protective charm against storms.
- The species Aloe mutabilis is currently considered as a form of Aloe arborescens.
Natural Distribution:
- Found in the WC, EC, KZN, Esw, M, L, G, and scattered distribution in Zim and Moz.
- North of southern Africa its range extends into Malawi.
Natural Habitat:
- Savanna-bushveld, thicket and grassland and forest.
- Occurs on cliffs and rocky slopes, in cool and high rainfall conditions.
Links to other other species of the Aloe genus.
To go to the “plant blog” click on the picture or the plant name below the picture.
Aloe marlothii
References:
Boon, Richard “Pooley’s Trees of Eastern South Africa, a Complete Guide” 2nd ed. 2010 Flora & Fauna Publications Durban
Hankey, Andrew (2001) & Notton (2004) “Aloe arborescens” 2nd ed. PlantZA Link Aloe arborescens
Joffe, Pitta & Oberholzer, Tinus “Creative Gardening with Indigenous Plants, ASouth African Guide” 2nd ed. 2012 Briza Publications Pretoria
Johnson, David & Sally & Nichols, Geoff “Gardening with Indigenous Shrubs” 2002, Struik Publishers Cape Town
Coates Palgrave, K C, edited Coates Palgrave, M C “Trees of Southern Africa” 2002 Struik Publishers Cape Town
Jeppe, Barbara “South African Aloes” 1969 Purnell & Sons SA (Pty) Ltd Cape Town
Palmer, E & Pitman, N “Trees of Southern Africa Volume 1” 1972 A A Balkema Cape Town
Schmidt, E, Lotter M Cleland W “Trees and Shrubs of Mpumalanga and Kruger National Park 2002 Jacana Johannesburg
Smith, Gideon F, Crouch, Neil R and Figueiredo, Estrelia “Field Guide to Succulents in Southern Africa” Struik Nature Cape Town
Van Wyk, A, van den Berg, E, Coates Palgrave, M & Jordaan, M Dictionary of names for southern African trees” 2011..Briza Publications Pretoria
Van Wyk, Ben-Erik & Smith, Gideon “Guide to the Aloes of South Africa” 2nd ed. 2003 Briza Publications Pretoria
Woodhall, Steve “Field Guide to Butterflies of South Africa” 2nd ed. 2020 Struik
© Malcolm Dee Hepplewhite & Witkoppen Wildflower Nursery, (Text and Photographs) 2012 & 2021.