Aloe season is in full swing and as one of the most popular genera in the gardening world, you will struggle to find a gardener who does not know what an aloe is. Of the 600 species that occur worldwide, South Africa is home to 155 (Africa as a whole has 405) with 46 red data list species (1). These include dwarf aloes, tree aloes, trailing aloes, edible aloes, poisonous aloes, tropical and desert aloes.
In this instalment, we will be providing a guide to aloe selection, care and pest/disease for future use.
Aloe hybrids are a common sight at nurseries for their colourful and long-lasting blooms.
Frequently Asked Aloe Questions
Is Aloe vera & Aloe ferox the same?
No, it is not. Aloe vera (Aloe barbadensis) is cultivated throughout the globe but is thought to have originated in the Arabian Peninsula. Aloe ferox is the most commonly produced aloe in SA and contains higher levels of aloin and amino acids than Aloe vera.
Check out their profiles below to compare the two species:
How do I get my aloes to flower?
You cannot force an aloe to flower. Most will flower when mature (+/-4 years). You can feed them dilute seaweed fertilizer during the flowering season to help with the carbon load associated with flower formation.
Why are there so many hybrids?
Due to most species being protected (see ‘permits’ below), it is easier to trade with hybrid species that do not fall under such strict regulation.
Aloes are protected under CITES Appendices I&II, which means you require a permit to transport / sell / trade listed species (2). A noted exception is Aloe vera, which does not form part of CITES regulation. For more on this subject visit Cape Nature Permits.
Can I eat aloe leaves?
Aloe vera has been reported to be edible, however, several Aloe species are highly toxic and one can easily confuse young plants so be vigilant (3).
Do animals eat aloes?
Yes, it forms an important part of both elephant and kudu diets. Several carpenter bees also utilize the fruit.
Do bees pollinate aloes?
Yes, bees play a role in pollinating several aloe species. Bees prefer a high protein content in pollen, which has led some honey farmers to use Aloe davyana pollen along with Sunflower and Eucalyptus to feed their hives.
Aloe are identified based on stem, leaf and flower structure. Multi-floral structures such as this Aloe striata is described as containing open racemes.
Aloes can be subdivided based on stem, leaf and flower structure in that order. This is a guide to how to describe your Aloe so you can get as close an id as possible.
- Stem structure: Single stem/Multi-stem/ Prostate (Flat on the ground), Tree/Shrub/Trailing
- Leaf structure: Rosette or stacked (distichous), thorns on edges/bottom, leaf has markings/striations
- Flower structure: Single vs multiple inflorescence, tubular vs bell-shaped flowers, open vs. compact raceme (tight vs space between florets)
For a comprehensive list on Aloes see The Aloe names book by Olwen Grace (3).
Aloidendron barberae, formerly Aloe barberae, can get up to 20m tall and produce orange blooms.
START YOUR COLLECTION
Selecting an Aloe for your garden, be it indoors or outdoors, can be very exhilarating. South Africa is home to some of the best Aloe breeders, so if you like hybrids then why not pop over to CND Nursery Candide profile and read about their wonderful association with De Wet's Aloes and The Aloe Farm. If you are in the Western Cape, you can visit Rooiklip Nursery for a look at their Sunbird Aloes.
If you are more partial to species than hybrids, then I have compiled a list of some interesting ones on the market.
You can go here for an online tour of an Australian collection or if you are thinking of collecting Aloe in the UK then why not have a look at Kirkstone botanica Aloe collection.
Trailing Aloe are of particular interest as they can be used for both indoor and outdoor scapes.
Aloes can grow independently given the correct growing conditions. That said, if you are growing your Aloe indoors or anywhere outside its natural habitat then you have to take some precautions.
- Growing medium: River sand:Gardening soil:Pebbles 2:2:1
- Exposure: Full sun
- Water: Around the stem during droughts and occasionally during summer
- Feed: Diluted seaweed fertilizer during growing months.
- Refrain from over-fertilizing as this will invite pests.
- Potting: The root systems are fairly shallow (25cm) and do not require deep preparation.
- Placing river sand or pebbles/rocks around the base will deter soil from accumulating in foliage and minimize fungal infections.
DO NOT water your Aloes from the top. This causes water to collect near the crown and pose a risk for diseases.
DO NOT over water. This is the main cause of diseased Aloe.
DO NOT plant your Aloe in regular potting soil. It will grow, but probably attain one or more diseases in the process.
DO NOT leave pests and diseases to spread. Treat any infections early on.
DO NOT place your Aloe in semi-shade without air circulation.
Aloe pests are often followed by diseases such as this infection of exposed tissue.
PESTS & DISEASES
Aloes are very resilient and can survive with minimal human intervention. If you find your Aloe on the sick side or infested with some unknown critter, then hop on over to our article on Aloe problems:
FOR: The Love of Aloes
Last, but not least, The Creighton Aloe Festival is a good opportunity to see the best of the best. It is currently scheduled for July 2020. So if you love Aloes then visit their site for more information visit (here).
And remember to SHOW us your Aloes!
Aloe attract a multitude of fauna and would be a great addition to any garden small or large.
(1) Grace, O., Klopper, R., Figueiredo, E. & Smith, G. (2011). The Aloe Names Book. Royal Botanic Gardens, Kew.
(2) SANBI (2010). Threatened Species: A guide to Red Lists and their use in conservation. Threatened Species Programme, Pretoria, South Africa.
(3) Grace, O.M. (2011). Current perspectives on the economic botany of the genus Aloe L. (Xanthorrhoeaceae). South African Journal of Botany, 77(4), 980-987.
(4) Maurizio, S., et al. (2012). CITES and Cacti a user's guide. Royal Botanic Gardens, Kew.