Aloe vera- Magic, Mystery and MythBy Geoff Stein (palmbob)
August 31, 2012
Though the plant, Aloe vera (aka Aloe barbadensis) is not one of the more interesting or beautiful of the Aloes, it is still a decent landscape plant, as well as one of the best indoors aloes there are. The only reason I have one in my collection is so the person who insists on chopping off all my aloe leaves in the front yard (an ongoing but unsolved crime for the last 5 years I have lived here) can at least have one plant that I do not care if he/she hacks off its leaves… and perhaps they will someday learn that THAT is the plant they are really looking for and all my other plants will either poison them or give them a rash so bad, they will stay away for a long time. I guess to some, all aloes look alike.
Aloe succotrina (left) butchered nearly weekly by some unknown neighbor- note the cut edges are purple- the is an identifying characgterisic of this and several other species of aloe (Aloe vera does not have purple cut edges); right is an Aloe pluridens the neighbor eventually hacked to death removing all the leaves, presumably for the 'magical effect' of the aloe leaves, perhaps thinking this was a form of Aloe vera...? I have no idea if Aloe pluridens has any of the same properties as Aloe vera, personally.
Two examples of large aloes that are actually trees, for those not aware of the existence of other Aloe species- Aloe barberae (left)- a humongous tree, and Aloe dichotoma (right) and nice, stately tree as well
two more varieties of Aloe that look nothing like Aloe vera- Aloe dorotheae (left) and miniature species Aloe krapohliana (right)
Here are two species that do look a lot like Aloe vera, but aren't: Aloe porphyrostachys (left) and Aloe vacillans (right). Aloe vacillans even has flowers that look almost identical to Aloe vera
No one is certain where Aloe vera came from, but many assume northern Africa or Arabia since there are references to what appears to be this plant in old Egyptian ‘writings’ where it was already being advertised as a healing plant. And since then it has been grown all over the world, naturalizing in many countries and tolerating many climates, from warm and tropical to extreme desert. It does not, however, tolerate much cold so its latitudinal spread has been somewhat limited… outdoors. It is one of the few Aloe species commonly sold and successfully grown indoors in just about any climate there is.
offsets being rooted in separate pots (photo by timmijo) left: right is photo of mature plant offsetting like crazy in Arizona (photo Xenomorf)
As an outdoor landscape plant, it is one of the few aloes that bloom year round, providing the grower with some brilliantly yellow flowers no matter what the season. Flowers are simple and arise on single or sparsely branched, upright, open racemes. Aloe vera plants with red flowers have recently been reassigned to different species (either Aloe koenenii or more commonly to Aloe officinalis)- these species are extremely similar in appearance, though most are smaller, more spotted and aggressively offsetting species. The Aloe vera plant itself is not the most ornamental of the Aloe species, and seems to have two completely different appearances, depending upon how it is grown. Outdoors, in a warm climate, this plant grows fairly large (up to over two and a half feet tall), not quite as wide (single rosettes about two feet in diameter maximum) and has pale grey-green leaves that may or may not have subtle white spots mostly near the leaf bases. The leaves are ‘armed’ with fairly innocuous, widely spaced white teeth. Eventually these plants offset and produce large colonies of plants. That is in fact the only way this species is propagated as no Aloe veras produce viable seed and haven’t for centuries. They spread entirely by offsetting (it is amazing that it has been naturalized in so many countries around the world since it cannot be reproduced by seed).
Aloe vera growing outdoors in southern California- left in a cactus garden, right in a garden of perrenials where it gets a lot more consistent water.
newly purchased aloe ($4) left; Mature aloe in planter (photo chgrpt) right
Aloe vera colony in southern California
plants identified as Aloe vera, but due to the non-yellow color of their flowers, are probably something else, such as Aloe officionalis (photo on right by cactus_lover)
flowers of 'true' Aloe vera showing proper color and shape of racemes.
Indoors the plant rarely flowers (it definitely seems happier outdoors) and tends to stay in its more juvenile leaf form- thin, pale green and heavily spotted, forming along etiolated, twisted tangles of long stems that eventually fall out of the pot. The glaucous bloom one often sees on the leaves on outdoor plants rarely develops on the indoor plants, making them much greener in comparison. The two plants (indoor and outdoor) look like different species side by side.
Aloe vera growing indoors (photo Pashta)
Cultivation of this species of aloe is fairly straight forward- well draining soil, water only when needed, bright light (full sun is best) and do not allow it to freeze. There are dozens of soil types and recipes that will support this plant and thanks to its adaptability, it can even survive soils that seem to retain moisture (unlike a lot of other Aloes). However, if grown indoors or in cool climates, this sloggy sort of soil can end up allowing Aloe veras to rot. Here in southern California, this plant can even be grown in clay soils fairly easily, but it rarely ever freezes in most areas, and most of the days are sufficiently warm to keep that from happening. When in doubt, add a lot of pumice to the soil- can’t hurt and it may prevent disaster.
Watering when needed just means if the soil is dry, water, or if the plant is looking dehydrated, water well. These amazing plants tolerate over-watering in many conditions quite well, but I do not recommend making a practice of that. Again, in California, overwatering outdoors is somewhat difficult if the soil type is right. On the other hand, if grown in the ground, underwatering is not so easy either, as these plants tolerate an amazing amount of abusive dehydration. Potted, underwatering is more of a real issue, particular during hot, dry summers and in clay, unglazed pots. Severely chronically dehydrated plants have to be eased slowly back into shape or they also can rot, since the long term dehydration can lead to root death and a weakened root system that will not be able to take advantage of a lot of successive watering.
The native land of this plant is suspected to be northern Africa or Arabia, where full, hot sun and very low humidity are the norm. It has evolved to deal with this sort of climate, as have many aloe species. And growing such plants indoors or in shade or in the tropics often ends up in loss of the plant. Amazingly, this one seems to tolerate all of the above, growing in wet tropics to shady yards to an entire life without any direct sun at all (not ‘happily’, though). As a general rule, the more light the better. However, as with all succulents (and most all plants), moving from a position of long term shade to full, hot sun will end likely end up in severe scorch and permanent leaf damage (or at least until those leaves are replaced by new ones). Acclimation needs to be slow if one wants to move their plant back and forth from indoors to a sunny locations outside (not really practical, actually).
This is about ‘middle road’ in terms of cold tolerance in the aloe family. Some are much more sensitive to frost, while others can tolerate a good deal of frost and even a short freeze without much damage. This species does not appear to be damaged at temperatures above 27F, but below that, leaf damage occurs, and outright death down in to the low 20s (though sometimes the plant will regrow from root stock if this happens).
It is the gel of the aloe that has gotten all the attention over the centuries, though the sap, juice or latex secreted by the outer layer of the aloe leaves has received its share of attention, too. But if one is intent on ingesting aloe leaves, or applying them to their skin, I suggest one peal off the outer layer of the leaf to removed the non-gel-producing tissues as the product in this part of the leaf is not quite as ‘user-friendly’. What is left is often referred to as the ‘fillet’ and it is a very gelatinous but still mostly leaf-shaped structure that comprises 99% of the aloe leaf mass.
Aloe I acquired from garden outlet store (left) and cut a leaf off of; right shows cut leaf edge
Cut leaf on two sides
Aloe leaf with skin layer removed (along with toxic products) exposing one side of the fillet (left); Aloe 'skin' with all the Aloin in it- underside view.
Aloe vera leaves for sale in grocery store(left) Aloe gel after processing (photo from Wikipedia)
The number of benefits assigned to this remarkable gel, and the number of conditions and diseases benefited from its use are nearly endless, and, I suspect, have been greatly exaggerated, and for certain most claims are anecdotal and unsubstantiated scientifically. Still, aloe products comprise a billion dollar industry and these products seem only to grow in popularity year after year. There are definitely some beneficial properties to Aloe vera gel. From seems to be ‘factual’ is that the gel does have some beneficial effects in treating mild burns and possibly in the healing of scar tissue. However, in terms of healing wounds there are conflicting reports. There may also be some mild topical antibiotic effects of the gel as well. Aloe gel also has several oral nutritional properties that include a few potentially useful and possibly bioactive antioxidants, a digestive anti-inflammatory effect, a potential to ease hyperlipidemia and a hypoglycemic property as well.
Aloe gels, sold for treating skin 'ailments' (too long a list to describe sometimes?)
The less-than-scientific uses for aloe gel include dozens of cosmetic and topical treatments and cures, from preventing sun burn, rapidly healing fresh skin wounds, treating radiation burns (this has been proven to be false advertising however), frostbite, viral warts, herpes, seborrhea, psoriasis, etc. There are almost no cosmetic product categories that do not have hundreds of aloe-containing options available (this includes even the pet shampoos, conditioners and other dermatologic products, too). The medicinal, internal effects are even more amazing, from stopping colon cancer, stabilizing blood sugar, curing yeast infections, protecting against kidney disease, curing Crohn’s disease and inflammatory bowel disorder/disease/syndrome, reduces acid reflux, antiviral activity, urinary cystitis, prevents kidney stones, soothes arthritic pain, halts the growth of various tumors and speeds the recovery from physical exertion. Though it is unclear the route it is given, aloe gel can also be used to treat hypotensive shock and reducing stroke and heart attack incidence. It can oxygenate the blood, too and improve physical endurance (at least I assume these two separately listed claims are related in this way). One of the most remarkable claims is that one will increase one’s life span by 10% by regularly ingesting this product (not sure how to refute or prove that one). Reportedly Aloe vera gel is also an excellent natural preservative though its use of one is reportedly limited by its inability to be patented for such use, therefore making aloe preservative an uninteresting product for most companies that manufacture preservatives. I am not sure I understand that argument as all other properties of this gel seem to be exploited to the maximum. One should note that most of the above claims are made by someone selling something.
More products for skin treatment with aloe in them
The latex from the outer layer of the leaf has been used for centuries as a laxative, but its main product (aloin) has been taken off the market due to lack of sufficient studies, and possibly due to one study that showed it has some carcinogenic effects in rats. Thus the ‘toxic’ nature of Aloe vera is often warned against, as well (Aloe vera is interestingly on many toxic plant lists, probably for this reason). This external leaf layer is also where almost all the nutrients exist that are listed by the promoters of aloe juice and oral supplements. Fortunately the toxic or laxative aloin can be extracted and eliminated from these oral supplements and juices. A video that covers this last concern can be seen on this link below that describes how aloe gel is processed in general, as well.
Some products that don't mention 'aloin' but have 'leaf' in them and discuss the laxative effect... so some products are still on the market it appears.
Video on how Aloe gel is processed: http://www.iasc.org/
Another site showing detail photos of removing the center fillet: http://www.naturalnews.com/PhotoTour_Aloe_Vera_1.html
All aloes have gel in their leaves but it is not clear if most or even a minority of these species contain similar gel to what is found in Aloe vera, though I suspect many of the properties and ingredients are the same. Most of these others species are not common enough in cultivation to be exploited in the same way Aloe vera has been, possibly due to Aloe vera’s exceptional adaptability as well as its lack of nasty, sharp marginal teeth so many other species possess. However, Aloe ferox is in a distant second place for being used for everything under the sun, and some argue this plant is superior in safety as it contains very little aloin, so the entire leaf can safely be used and processed. For more on Aloe ferox and its miraculous (but unproven) properties, see the link below. Interestingly many aloes have various colored gels, some which are even useful in their identification. I wonder if any of these brilliantly colored gels have been researched enough to discover what miracles could be boasted about.
Aloe ferox is an excellent landscape plant, as well as having a long list of medical uses
Other aloes may have useful saps as well... who knows. This Aloe rubroviolacea is a particularly juicy species, producing a brilliant yellow sap, the peculiarly turns a deep purple as it dries (see stains on concrete)- good medicine?
Links to sites showing Aloe processing photos and facts: