The krantz aloe is a valuable garden asset, it has large beautiful flowers, attractive foliage, decorative form, and it is easy to grow. It is also a 'must-have' for anyone wanting to stock their herb gardens with indigenous healing plants.
Description The krantz aloe develops into a multiheaded shrub 2 -3m high with striking grey green leaves arranged in attractive rosettes. The leaf margins are armed with conspicuous pale teeth.
The large colourful flower spikes are borne in profusion during the cold winter months (May-July), brightening up a drab winter garden. Deep orange is the most common colour, but there are also pure yellow forms, and an unusual bi-coloured form of deep orange (almost red) and yellow. The inflorescence is usually unbranched, with two to several arising from a single rosette. As with all the aloes, the flowers produce nectar and are attractive to many kinds of birds, in particular the small and colourful sunbirds, which flit from flower to flower in search of nectar. The flowers also attract bees.
The species formerly known as Aloe mutabilis is now regarded as a synonym of Aloe arborescens. It is a cliff dwelling form with smaller, less branched rosettes and red & yellow bi-coloured flower spikes and is more evident on the high inland plateau of the northern provinces of South Africa. This cliff dwelling form of Aloe arborescens can be seen hanging from the cliffs alongside the waterfall at the Witwatersrand National Botanical Garden.
Although it is in fact a large much-branched shrub, Aloe arborescens has been allocated a national tree number (28.1).
Distribution This species is distributed mainly over the eastern, summer rainfall areas of the country. It has the third widest distribution of any aloe, occurring from the Cape Peninsula along the eastern coast, through KwaZulu-Natal, Mpumalanga and Limpopo province and further north into Mozambique, Zimbabwe and Malawi. It is one of the few aloes that can be found growing at sea level right up to the tops of mountains. The krantz aloe is adapted to many habitats, but is usually found in mountainous areas where it favours exposed ridges and rocky outcrops. It is also found in dense bush.
Derivation of the name & historical aspects The name aloe is from the Greek alsos and refers to the bitter juice from the leaves of these plants. It is probably derived from the earlier Arabic word alloeh or the Hebrew word allal, both meaning bitter. The Latin word arborescens means tree-forming or tree-like, and is a bit misleading in that this aloe is not really tree-like, but the name was originally applied to this species in reference to the stem-forming habit. The common name krantz aloe refers to its habitat, a krantz being a rocky ridge or cliff.
Aloe arborescens is one of approximately 130 Aloe species native to southern Africa. It is possibly the most widely cultivated aloe in the world and can be seen grown in gardens in many cities around the world. It was one of the first South African aloes collected and planted in the Company's Garden in Cape Town. It was grown in Amsterdam by Professor Commelin in 1674, and featured in Hort. Amst. 2 in 1701.
Uses and cultural aspects In many parts of South Africa Aloe arborescens is planted around kraals (domestic stock enclosures) as a living fence. It often happens that the position of old kraals can still be seen many years after they have been abandoned because the aloes persist. Cuttings intended for use as barrier pla