Introduction to Aeoniums
(Editor's Note: This article was originally published on May 12, 2008. Your comments are welcome, but pleasebe aware that authorsof previously published articles may not be able to respond to your questions.)
Most Aeoniums come originally from the Canary Islands off the coast of Spain in the Atlantic Ocean, with a few oddball species from several isolated parts of central Africa. The climate of the Canary Islands is fairly Mediterranean so these plants are perfectly adapted to many similar climates around the globe. Most are moderately drought tolerant (though less so than most might guess), mildly frost tolerant (some more than others), but only moderately heat tolerant as well, and dependent on bright light to full sun. These are generalizations and there is certainly some variation in their water, heat and lighting needs.
Aeoniums are members of the Crassulaceae, a huge family of succulents that include many other popular and commonly grown succulents, including some that look a lot like Aeoniums. Echeverias in particular are often confused with Aeoniums and there are several other rosette-like succulents (eg. Dudleyas, Graptopetalums, Pachyverias and Graptoverias). One thing that sets t these plants apart is the way their leaves attach to the stem- they are wrapped around the stem with a fibrous attachment so that when a leaf is pulled away, the stem is intact with only a transverse line showing where the leaf was attached. The other rosette Crassulaceas have succulent attachments and their being pulled off the stem leaves a divot in the stem.
Echeverias and Aeoniums can sometimes be confused... these are Echeverias and Echeveria hybrids: sedundiflora, nuda-ciliata and set-oliver
Graptopetalums, Graptoverias and Pachyverias also somewhat resemble Aeoniums
Aeoniums were even once included in the genus Sansevieria (examples shown here)
Aichrysons are commonly sold as Aeoniums and are closely related; the first one here is my own plant sold as Aeonium 'domesticum', and the other is a show plant, Aichryson bethencortianum
The roots of Aeoniums are pretty wimpy and hair-like with all the water-storing parts of the plants being in the stem and leaves. These wimpy roots are prone to drying out and many of these plants decline if not keep moist for at least most of the year (a few exceptions exist, and those will rot if watered in summers). Many Aeoniums will produce aerial roots that grow right out of the stems, particularly if the stems are getting long and leggy, or fall over, or are in a cramped pot.
Aerial roots on Aeonium urbicum and Aeonium haworthii
These two shots are of same plant (2' tall Aeonium arboreum 'Atropurpureum') showing dinky root size compared to rest of plant
Aeonium stems showing the leaf scars
Most Aeoniums are winter growers looking their best when temps are moderate and water plentiful. As summer approaches many will curl their leaves in and go into a form of dormancy, though in cultivation, given some shade and water, most will continue to grow actively, though perhaps less vigorously. Hot summer sun will damage Aeonium leaves and some will curl up and in as a protective response.
Heat damage on Aeonium 'Cyclops' and burned leaves on Aeonium 'Sunburst'
These are not cold weather plants however and freezes will damage most species. Mine all were pretty severely damaged during a severe freeze (severe for southern California that is- down to 25F for nearly a half day) with the exception of Aeonium haworthii, which only had ‘waves' of frost damage on parts of the plants. All the rest melted, but all also recovered, and were looking pretty much normal by the summer.
melted Aeonium 'Cyclops', and my own Aeonium 'Zwartkops' along with those planted in nearby botanical garden, all melted from a single night's freeze here in Southern California a few years ago
Starting as a naked stem after the frozen, dried leaves fell off, this Aeonium arboreum 'Zwartkop' makes a quick recovery
Most Aeoniums are monocarpic, meaning they die after flowering. For unbranching species this means the death of the entire plant and offspring is only created by germination of the seeds. Some flowers are spectacular terminal events while other species have relatively insignificant flowers.
These Aeonium 'Voodoos' will die after this flowering even, as did these Aeonium urbicums (all visible are the stems and old flowers); close up of an Aeonium flower
These Aeoniums will survive the flowering event as all are either highly branching species, like the Aeonium haworthii and Aeonium leucoblepharum, or have low stem offsets/branches like my Aeonium undulatum hybrid in this last photo (just starting to make a flower)
Of course there is always genetic variation among most plants species, and as is the case with solitary Agaves that I discussed in a previous article, some solitary Aeonium species will have rare individuals in nature that branch or sucker. It is these rare individuals that collectors find and mass produce so that by the time we collectors acquire these species most we find in cultivation are the suckering forms (so much easier and more profitable to cultivate), giving us the impression this is how these plants behave in the wild.
Aeoniums are ideal pot plants needing very little other that soil for support and water. Rarely does one need to fertilize these plants. If growing Aeoniums along the coast, the humidity and rains/mists will often mean they never need to be water, either. But in dry climates they will probably need to be watered frequently or put on drip irrigation. I have rarely overwatered an Aeonium and the more frequently I water the ones I have , the better they look. They do not need to be thoroughly watered, though as the main water-absorbing roots are near the surface with the deeper roots functioning nearly solely as support.
My onw Aeonium nobile is a great pot plant being exceptionally drought tolerant for an Aeonium; this Aeonium arboreum can live in this pot for years, but does need regular watering
Pot life also means one can move the plants in and out good and bad weather situations. As mentioned already, these plants do not like heat, and high temps will often cause root death, and then plant death. So during high heat times of year, they may need to be moved indoors in a window (indoors in low light is also very difficult for these plants and most will quickly weaken and colors will fade). Soil type is not a big issue with potted plants, but generally Aeoniums perform better in standard potting soils rather than super well draining and nutrient deficient cactus soils. Remember these plants do not like to dry out. Repotting is good for the health of the plant, but should be done ideally after summer's over, near the start of the main growing season.
potted plants for sale at a So. Cal. nursery
Growing Aeoniums in the garden requires one to have a garden in the right climate- the ideal climates are Mediterranean- relatively dry with seasonal rainfall (preferably in winters, not summers) and no freezes. Growing these plants in the tropics, the hot deserts or where it snows will be very difficult. Soil types can be varied as most Aeoniums will grow in most soils, as long as they are not pure clay, or excessively alkaline or acidic.
my own unknown hybrid and a sale plant suffering a bit from lack of water
Compared to many other Crassulaceae succulents, I find these plants to be nearly problem free except for dealing with the environmental extremes mentioned already. I rarely find pests on these even in the same planter boxes that have Echeverias covered with aphids or Sempervivums that are fighting off mealy bugs. Occasionally I find a bite taken out by a grasshopper (or my parrot) and now and then I can find some slug damage. That does not mean that these plants are made of armor, and all the normal bugs can do their damage... it just seems to me that given a choice, most of the normal bugs prefer something else in the garden. I think most of my losses have been from excessive sun and heat, and dehydration. Rarely do I get one rotting but some that I have shoved into the heavy clay soils we have here have developed some degree of fungal problems particularly in very wet seasons (or heavily watered areas).
I get mealy bugs on crests regularly where the leaves are abnormally close and retain moisture, and hide bugs
The following are some of the more common plants and hybrids found in cultivation. There are many other species but most are hard to find and unlikely to ever even be seen unless one visits a botanical gardens or a cactus/ succulent show.
Aeonium arboreum is one of the more commonly available species, though most plants in cultivation are hybrids of this species. This is a bright green plant with a branching stem and is the ‘classic' Aeonium with the moderate sized rosettes and somewhat thin, spoon-shaped leaves. It is a very easy plant to grow and cuttings can be rooted simply by taking a stem and shoving it in the ground. As plants get taller (will grow up to 6' tall or more, but usually collapse after that) and more leggy, limbs will often start falling off from weight of the rosettes. These can be replanted in the garden or in pots but some of the stems should be cut off. This species is relatively heat and cold sensitive with the thin leaves curling in heat or melting in frost. But generally the plants recover quickly.
Aeonium arboreum var holochryson in winter and same plant in summer in middle photo; close up of potted plant on right
Variegated Aeonium arboreum on sale table at a plant show
Aeonium arboreum 'Atropurpureum' is the same plant but with purplish leaves that fade to green in shade but darken to maroon-purple in sun. This hybrid is probably the most common Aeonium for cultivation here in California.
All photos are of the same plants or cuttings of the same plants in my yard showing how Aeonium arboreum 'Atropurpureum' can vary in color depending on my much light it's getting
Two close up shots of Aeonium arboreum 'Atropurpureum' in my yard, and a photo of a crested form at a plant show
Another shot of one of my plants, and a small crested plant of ours
Aeonium arboreum 'Zwartkop' is one of the most ornamental of all the Aeoniums having nearly black leaves in full, hot sun, though these fade to purple in winter or shade.
Aeonium arboreum 'Zwartkops' growing in my yard, and in a botanical garden; close up of my plant in last photo
Flowering plant; second photo shows that plants only look black in certain lights- actually they are deep, dark red-purple
Aeonium 'Garnet' is a bright red plant that is a hybrid of the Zwartkop plant and Aeonium tabuliforme (see below) that is a nice, low growing, offsetting plant with big round leaves and fantastic color in full sun.
Aeonium 'Garnets' in botanical garden
Aeonium balsamiferum is a pretty rare plant in cultivation and looks a lot like Aeonium arboreum- 2'-3' tall, smooth stems and green, somewhat thin leaves. However, this species has sticky leaves, which Aeonium arboreum does not.
Aeonium balsamiferum growing in a botanical garden
Aeonium canariense is far less common in cultivation, but still can be found in some specialty nurseries. The hybrids of this species are more common and sometimes show up in outlet nurseries and garden centers. This is a non-branching plant normally, though most cultivated forms offset and all the hybrids branch. It has a thick smooth very short stem and is fairly slow-growing. Rosettes are large (up to 2' in diameter) and the leaves are somewhat cup-shaped. Some forms are fuzzy or sticky leaves and some have smooth leaves. Leaves are a light green but fade to a nice pinkish red near the ends on the older outer leaves.
Aeonium canariense in Huntington Gardens... note no stems; plant in the wild (thanks to albleroy), and a close up of a botanical garden plant
Aeonium canariense in So. Calif. gardens
Aeonium castello-paive is a smaller species with very thin, weak, woody, branching stems and succulent, flexible leaves with a smooth surface. This species is often confused with two other similar looking species, Aeonium decorum and Aeonium haworthii. I personally have a difficult time distinguishing these plants, but this one has the softest, most flexible leaves of the three, and the hybrid ‘Suncup' is probably the most commonly encountered form of this in most garden outlet centers.
plants in botanical gardens (Aeonium castello-paive)
variegated Aeonium castello-paives, aka Aeonium 'Suncups'
Aeonium cunetaum is a plant that grows by stolons which is not a common strategy among Aeoniums. This is a nearly stemless (sometimes stems up to 3' long) species with slightly bluish leaves and is not common in cultivation.
Aeonium cuneatum in botanical gardens
Aeonium davidbramwellii is somewhat common in cultivation, but the hybrid 'Sunburst' is by far more common and sold just about anywhere Aeoniums can be purchased. This is one of the most variable species and even on its native island of La Palma in the Atlantic this plant can look very different in different situations. Some plants are single stemmed and quite large, while others have numerous branches with much smaller rosettes. It has relatively thick somewhat rough-surfaced leaves generally with red or pink along the margins, which also are serrated with miniscule teeth. Possibly most plants identified as this are something else, and some plants identified as something else are this. But the hybrid Sunburst is quite distinct and a highly ornamental plant. It is nearly always a branching plant with rosettes up to 1' in diameter and various amounts of yellow, white and pale green stripes, often tipped with red or pink along the margins or fading to that at the ends of the older leaves. These plants are fairly easy to grow and more cold hardy than Aeonium arboreum. All of mine survived our 25F freeze with no damage at all... though hot sun can damage the leaves if in full afternoon exposure.
Aeonium davidbramweliis in botanical garden
Aeonium davidbramwelli 'Sunburst' is probably my favorite of all the the Aeoniums, at least in terms of beauty AND ease of cultivation. This is a very hardy and easy plant that grows well in sun, shade, and somewhat cold hardy. It does tend to burn in full, hot sun, particularly if the rosettes are primarily white or yellow. This is also a very common plant in cultivation and not expensive.
All three photos are of Aeonium davidbramwellii 'Sunburst' in my garden. Middle photo is of some plants starting to form crests
two photos of rosettes that have nearly no green left in them. These need protection from the sun! Third photo shows even though this species is somewhat frost hardy, it too melted at temps around 25F
crested Aeonium 'Sunburst' in my yard; plants for sale in local southern California nurseries; this last plant was 'planted' by just dropping it on the ground, and it rooted where it fell- easy plants!!
Aeonium decorum is another of the small-rosette, highly branched, thin-stemmed species that can be very difficult to identify correctly. It is not nearly as common in cultivation as Aeonium haworthii and most plants identified as this are probably Aeonium haworthii. About the only major difference is the stems of this species are relatively smooth in comparison to Aeonium haworthii stems.
Aoenium decorum in Huntington Botanical Garden- in winter, then again in summer, and lastly in spring, blooming
Aeonium gomerense is pretty uncommon in cultivation, but it can be found and grown. It is a relatively low-growing species with smallish rosettes between 4"-8".
Aeonium gomerense in garden, and in plant show- thanks Happenstance and Xenomorph
Aeonium goochiae is a pretty rare plant and perhaps not the most ornamental of the Aeoniums. It has thin, floppy stems and relatively small rosettes of only 2"-3".
photo of Aeonium goochiae by Thistlesifter
Aeonium haworthii is probably the most hardy and easy to grow, as well as one of the two most common species in cultivation. It has thick, short, rough-surfaced leaves that are not flexible at all (without breaking) that form rosettes about 3" in diameter, and grows in thick, dense clumps supported on a multibranched network of thin, woody, rough-surfaced stems. This plant often has lots of aerial roots drifting down from its stems. Cuttings grow easily and quickly after being stuffed in the ground- this plant grows so well it could even be classified as invasive. I have so many clumps of this in the yard I am now having to rip them out of the ground as they outcompete anything nearby and eventually cut off all the available sunlight from anything lower growing. Now I try to relegate this plant to pots or areas where I don't care if it gets out of hand. Despite all its hardy attributes, it still looks sad and weak if not watered enough, but is probably more drought tolerant than all the other Aeonium species.
Aeonium haworthiis in my yard
Aeonium haworthii ‘Kiwi' (also called 'Tricolor') is another very commonly sold plant and another one quite easy to grow. Fortunately this hybrid is lower growing and less of a garden nuisance than the parent plant. Aeonium 'Kiwi' has yellow green and pink leaves that form durable rosettes up to 4" in diameter, somewhat larger than the rosettes of Aeonium haworthii. The yellow (variegation) is only on the newly forming leaves at the center of the rosettes, and older leaves are all green with a consistent red-pink margin. It is a striking and excellent garden or potted plant.
Aeonium haworthii 'Kiwi's in my yard, and last photo shows young seedlings in a nursery
Aeonium lancerottense is pretty uncommon in cultivation and looks a lot like Aeonium percarneum (see below). It's stems are somewhat silvery and shrubs grow about 3' tall. Branches off the main plant are very thin and weak
Aeonium lancerottense showing unusual branching behavior; close up of rosette; and flowering, all in Huntington Botanical Gardens
Aeonium leucoblepharum is one of the species NOT from the Canary Islands. This species grows in east Africa and is an extremely variable species. Some plants have rounded leaves while others have very prominently pointed ones, some with dark stripes down the middle and others with none. Some forms are nearly stemless and others clumping up to 6' tall. It is far too variable for me to tell it from anything else.
Huntington garden plants in winter, blooming in spring, and basically dormant in summer
Aeonium lindleyi is a moderately rare plant in cultivation with smallish rosettes and slightly sticky leaves. It grows in small, woody branching stems.
Aeonium lindleyi in a botanical garden, and flowering in the wild (thanks albleroy)
Aeonium lindleyi var viscatums at two different times of the year
Aeonium nobile is not a very common species, but seems to be becoming more and more available recently. This is a stemless large plant and one of the most amazing and ornamental of all the Aeoniums. It is also the one most often misidentified as an Echveria thanks to its lack of stem. Rosettes can get up to 2' in diameter. It has thick, smooth pale green spatulate leaves that fade to a yellow or rust in full sun (where it likes to be). It is slow to offset and usually does so within the leaves. This species is not a good cold weather one as frosts even barely into the high 20s will damage it, and it can subsequently rot if it does not warm up soon after.
Aeonium nobile in landscape, in a pot and being shown (looks to be a bit too shade grown), and showing 'suckering' behavior in this last photo
Aeonium percareum may or may not be a common species, as it looks a lot like several other species. To me its leaves look a bit like those on Aeonium davidbramwellii, or like large Aeonium haworthii leaves with the rough, barely serrated leaves. Leaves are rough surfaced and form rosettes about 4"-5" in diameter. I include it here only because I cannot distinguish this one easily and it could be one the reader might encounter.
Aeonium percarneum in botanical gardens, and last photo of one in private collection (thanks Thistlesifter)
Aeonium ‘pseudotabuliforme' is a highly ornamental low-growing, offsetting form of Aeonium arboreum x Aeonium canariense and looks somewhat like Aeonium tabuliforme, only in that is has smooth leaves, isn't quite as flat to the ground, and offsets so prolifically. This is not a common hybrid in cultivation, but it can be found and makes a great groundcover plant.
Plant at the Huntington gardens... I have not seen this for sale anywhere, though
Aeonium sedifolium is unlike any other Aeonium having very small rosettes of 1" or less, densely packed on short, branched shrubs only about 6" or more high. I was surprised that it was even an Aeonium having owned one for a year before it was finally identified correctly. I got it as a dinky succulent natural succulent bonsai with dark leaves forming sparse rosettes of only 4-8 dinky ovoid succulent leaves each, all pointing upright. It was supported by a very thin-stemmed network of branches and stems. Unfortunately I nearly baked it to death in full sun and didn't water it near well enough. Fortunately it has recovered and is slowly growing back to its former amazing little bonsai shape.
My Aeonium sedifolium when I first got it... then, after hot summer of too much sun exposre; third is someone's award winner at a plant show
Aeonium simsii is not a very common species, but a hybrid of it is. This is a nearly stemless prolifically offsetting plant with lancelote leaves that end in a point. Leaves are bright, light green and have distinct hairs long the leaf margins. I have no personal experience with this species.
photo of Aeonium simsii by Dennisware- looks like the real thing, but hybrids can look similar, too.
Wonderful Aeonium simsii hybrid (with Aeonium 'Zwartkop') in the Huntington Gardens.
Aeonium spathulatum is another somewhat rare species in cultivation with spoon-shaped small leaves that curl up in summers. It forms a low shrub on skinny branching stems with peeling bark
Photo of Aeonium spathulatum by Happenstance (thanks!)
Aeonium tabuliforme is not super common, either, but I see it often for sale at specialty nurseries. This unique species is stemless and basically ‘hugs' the ground in large, flattened somewhat fuzzy rosettes consisting of many dozens of leaves. It is an amazing and highly ornamental plant, but should be confined to a pot in cultivation. This is NOT a good garden plant, having little tolerance of any heat or drying out. I have invariably lost every plant I have obtained either due to cold damage, heat damage (the most common cause), and over and underwatering. But I have not tried growing one in a pot and reportedly they are pretty easy in that respect.
Aeonium tabuliformes for sale at local nursery, southern California; my sad garden plant (while still alive); nice arrangement by California Cactus Center of these plants and some Echeverias
Aeonium tabuliforme photo by Happenstance and a blooming one by albleroy- thanks!
Aeonium undulatum- this is large species, usually solitary stemmed, but sometimes branching at ground level. Stems up to 7' tall and thick and smooth. Rosettes are about 10"-16" in diameter and have spatulate leaves that do NOT undulate (though some hybrids of this do and are often misidentified as this). Not sure actually why this is called undulatum. Most plants similar to this encountered in cultivation are hybrids of it.
Aeonium undulatums in botanical gardens (first two photos) and my own hybrid of one in last photo
My hybrid up close, and early flowers
Aeonium urbicum is another giant species that never offsets or branches and is similarly tall however with slightly smaller rosettes. This is much less common in cultivation and is identified by its newest leaves at the center of the rosette being bent downward at the tips. Note that many stemless or suckering plants sold in nurseries with very large rosettes are otften sold as this species, but are incorrectly named (sometimes the name 'Dinner Plate Aeonium' is given to these incorrectly identified plants). These are more likely some hybrid of Aeonium undulatum
Aeonium urbicums at two different botanical gardens
Aeonium 'Cyclops' and 'Voodoo' are hybrids of this species with the 'Zwarkop' variety of Aeonium arboreum. Both are large, branching plants with red-purple ('Cyclops') or black leaves ('Voodoo') and make excellent garden plants. I have Aeonium 'Cyclops' in my collection and it is one of the most marvelous Aeoniums I grow. The seasonal color changes and shapes are captivating and it is a simple, easy plant. Only probable I had was in the freeze when it completely defoliated... but recovered 100%.
My Aeonium 'Cyclops' in first and third photos with landcaping with this hybrid in botanical garden in middle photo
Aeonium 'Voodoo' in Huntington Gardens