Aloe excelsa (Zimbabwe Aloe)

Aloe excelsa (Zimbabwe Aloe)

Scientific Name

Aloe excelsa A.Berger

Common Names

Zimbabwe Aloe, Noble Aloe

Scientific Classification

Family: Asphodelaceae
Subfamily: Asphodeloideae
Tribe: Aloeae
Genus: Aloe

Description

Aloe excelsa is a single-stemmed succulent that grows up to 20 feet (6 m) tall. Leaves form a compact rosette at the top of the stem, spreading and becoming recurved. They are fleshy, dark green, up to 3.3 feet (1 m) long, and up to 1.2 inches (3 cm) thick at the center. All but the lowest part of the trunk is swathed in the remains of dead leaves. Young plants have a great number of spines over their leaf surfaces. However, as they are taller and less vulnerable to grazing, these brown-red teeth disappear and remain only on the leaf margins. This species is frequently confused with the related Aloe ferox and Aloe africana. They do look very similar when fully grown. However, the flowers are different, with the racemes of A. excelsa being far shorter and slightly curved.

Hardiness

USDA hardiness zones 9b to 11b: from 20 °F (−6.7 °C) to 50 °F (+10 °C).

How to Grow and Care

Aloe is a very forgiving plant, and a well-grown plant can be quite beautiful. As with all succulents, Aloe must never be allowed to sit in stagnant water, and the plant should be carefully monitored to watch for signs of overwatering.

These succulents are not particularly fast-growing and will only rarely need repotting. In the spring, repot Aloes that are tipping over their pots or have ceased growing. Use a fast-draining potting mix with one-third sand or pebbles. During the repotting of a larger plant, it is possible to divide the root ball carefully. Some varieties of Aloe will send off offsets that can be potted independently.

Aloe plants need strong, bright light. They can withstand full summer sun once acclimated. In the winter, provide bright light. It prefers warmer temperatures of 70 to 80 °F (21 to 27 °C) but will survive down to 40 °F (4.5 °C). Feed with a succulent fertilizer in the summer only. Suspend feeding in the winter as the plant goes dormant. See more at How to Grow and Care for Aloe.

Origin

Aloe excelsa is native to Zimbabwe, Zambia, Malawi, northwestern South Africa.

Links

  • Back to genus Aloe
  • Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus

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Aloe Species, Noble Aloe, Zimbabwe Aloe

Category:

Water Requirements:

Drought-tolerant suitable for xeriscaping

Sun Exposure:

Foliage:

Foliage Color:

Height:

Spacing:

Hardiness:

USDA Zone 9b: to -3.8 °C (25 °F)

USDA Zone 10a: to -1.1 °C (30 °F)

USDA Zone 10b: to 1.7 °C (35 °F)

USDA Zone 11: above 4.5 °C (40 °F)

Where to Grow:

Danger:

Plant has spines or sharp edges use extreme caution when handling

Bloom Color:

Bloom Characteristics:

Bloom Size:

Bloom Time:

Other details:

Soil pH requirements:

Patent Information:

Propagation Methods:

From seed winter sow in vented containers, coldframe or unheated greenhouse

From seed germinate in vitro in gelatin, agar or other medium

Seed Collecting:

Regional

This plant is said to grow outdoors in the following regions:

Vista, California(9 reports)

Gardeners' Notes:

On Mar 21, 2018, DMichael from Fort Lauderdale, FL wrote:

One of only several tree Aloes which perform well and bloom in Ft Lauderdale’s subtropical/tropical 10b Climate. Was planted 10 years ago with a Dune Aloe (A. thraskii), winter solstice bloomer here, which performed and bloomed exceptionally well until Hurricane Irma felled it. As a result, A excelsa received more sun and took off. It is a spring Equinox bloomer here, with foot long vermillion-orange inflorescence, and contrasting deep-aubergine filaments. The olive-green leaves have the occasional solitary tooth in the middle - both above or beneath. Less showy than A thraskii out of bloom, more showy than A. thraskii in bloom. Aside from Fairchild Tropical Gardens, I’m the only one I know of experimenting with - and having good success - with some Tree Aloe species in SE FL.

On Dec 10, 2003, palmbob from Acton, CA (Zone 8b) wrote:

This is one of the larger non-branching tree aloes. makes a nice, tall tree eventually with long, arching green leaves. Most adult plants have smooth leaves, but some maintain the leaf spines typical of immature plants. Some well treated plants can have quite large, healthy leaves, though. Color of flowers variable - usually reddish, but can be orange, yellow and even white. Flowers are typically flatted downward on racemes and at slight angles, making them distingishable from Aloe ferox flowers which intially look very similar (plant does, too). Aloe ferox racemes are usually much longer and perfectly erect, without a slight slant or without the markedly flattened flowers. Aloe excelsa flowers usually bloom in late winter and are always spectacular.

My smaller plant . read more looks a lot like several other tree aloes, including Aloe marlothii and Aloe ferox.

From Zimbavwe Africa and not endangered.


Distribution and habitat [ edit ]

The Zimbabwe aloe is named for the large number of specimens found growing around the ruins of Great Zimbabwe, where it has attracted much attention for its size and shape.

It is found over a relatively small area of south-central Africa from the Magato mountains in Limpopo province of South Africa at its southern limit, northwards along the southern side of the central watershed of Zimbabwe and extending into hilly locations on the south side of the Zambezi river in Mozambique, with two outlying populations forming its northern limits around Mulanje mountain in Malawi and in the Kafue Gorge just across the Zambezi river in Zambia. [2]

Within this range, it favours localities with good drainage and moderately stable soils, such as rocky, wooded hillsides. It is restricted by too much heat in the dry season to the north and cold winds in the winter season to the south. It tolerates light frost during its resting (and flowering) season which occurs occasionally at its favoured altitudes of 800–1600 metres. [3]


The Zimbabwe Aloe is a tall aloe, sometimes reaching tree dimensions of 5–6 metres, although 3 metres is a more common height. It is single-stemmed and all but the lowest part of the trunk is swathed in the remains of dead leaves. The leaves form a compact rosette at the top, spreading becoming recurved and up to 1 metre long. They are dark green in summer and succulent, up to 3 cm thick at the centre. Similar to some other aloe species, young plants have a great number of spines over their leaf surfaces. However, as they taller and less vulnerable to grazing, these brown-red teeth disappear and remain only on the leaf margins. [1]

This species is frequently confused with the related Aloe ferox and Aloe africana species, to the south, and they do look very similar when fully grown. However the flowers are different, with the racemes of Aloe excelsa being far shorter and slightly curved.

The Zimbabwe aloe is named for the large number of specimens found growing around the ruins of Great Zimbabwe, where it has attracted much attention for its size and shape.

It is found over a relatively small area of south-central Africa from the Magato mountains in Limpopo province of South Africa at its southern limit, northwards along the southern side of the central watershed of Zimbabwe and extending into hilly locations on the south side of the Zambezi river in Mozambique, with two outlying populations forming its northern limits around Mulanje mountain in Malawi and in the Kafue Gorge just across the Zambezi river in Zambia. [2]

Within this range, it favours localities with good drainage and moderately stable soils, such as rocky, wooded hillsides. It is restricted by too much heat in the dry season to the north and cold winds in the winter season to the south. It tolerates light frost during its resting (and flowering) season which occurs occasionally at its favoured altitudes of 800–1600 metres. [3]

It has attracted the attention of gardeners and parks planners for its imposing appearance and tolerance for a wide range of conditions. In its natural habitat, it thrives best when given plenty of water during its growing season but requires a sharp dry period with cooler conditions when the impressive flowers appear.


Aloaceae Literature

Rowley, G D (2013) Generic concepts in the Alooideae Part 3 - The phylogenetic story.
Alsterworthia International 13(2) 24-26 publication dated July 2013

Daru, B H, Manning, J C, Boatwright, J S, Maurin, O, Maclean, N, Schaefer, H, Kuzmina, M & van der Bank, M (2013) Molecular and morphological analysis of subfamily Alooideae (Asphodelaceae) and the inclusion of Chortolirion in Aloe. Taxon 62 62-76.

Aloes: The Definitive Guide by S. Carter, L. E. Newton, J. J. Lavranos, C. C. Walker
Hardback ISBN-13: 9781842464397 Pub. Date: August 2011

Aloes in Southern Africa by Gideon Smith & Braam van Wyk
Paperback ISBN-13: 9781770074620 Pub. Date: 09/01/2008

The Aloes of South Africa by G.W. Reynolds (1982) 4th Edition
Publisher: A.A. Balkema, Cape Town, South Africa. ISBN: 0-86961-128-3
- out of print classic but often available second-hand.

South African Aloes by B. Jeppe (1977) 2nd Edition.
Publisher: Purnell, Cape Town, South Africa. ISBN: 360-00018-5
- out of print, many species illustrated with colour drawings.

Gasterias of South Africa: A New Revision of a Major Succulent Group by E.J. van Jaarsveld (1994)
Publisher: Fernwood Press (Pty) Ltd., Vlaeberg, South Africa. ISBN: 1-874950-01-6
- a beautifully illustrated classic, often available second-hand

Haworthia and Astroloba: A Collector's Guide by John Pilbeam (1983)
Publisher: B.T. Batsford Ltd., London. United Kingdom. ISBN: 0-7134-0534-1
- out of print classic but often available second-hand.

Illustrated Handbook of Succulent Plants: Monocotyledons Edited by Urs Eggli (2001)
Publisher: Springer-Verlag New York. ISBN: 3540416927
Volume relevant to Aloes from a series of comprehensive taxonomic treatments of succulent plants.


Watch the video: My Aloe Collection 1 Aloe Series