There really is no way to neatly classify succulents. Many are spiny cacti with fleshy stems without recognizable foliage. Others are euphorbs (related to poinsettias) that may resemble cacti, or may instead have fragile leaves on fleshy stems. Aloes and agaves have bold rosettes of fleshy leaves that obscure their wide basal stems.
The most familiar succulents are small docile perennials, like the many varieties of jade plants and iceplants. Some are flowering perennials like begonias. A few are even grown as annuals, like busy Lizzie (impatiens).
So what do succulents have in common? Well, that is a good question that is open to interpretation. Most would agree that succulents have some sort of fleshy succulent parts for storing water through dry weather. These succulent parts are most often leaves or stems. Yet, yuccas, dracaenas and ponytail palm that are no more succulent than palms, are considered by many to be succulents like related aloes and agaves.
Many succulents are remarkably easy to propagate vegetatively (without seed). Most aloes, some agaves and many yuccas produce pups, which are basal shoots that can be separated as new plants. Agaves that do not produce pups while young will likely produce many pups after they bloom and begin to deteriorate. (Individual rosettes die after blooming.)
Despite the nasty spines that make them difficult to handle, cactus that produce multiple trunks can likewise be divided. Cactus can alternatively be propagated as large cuttings; but because they are so fleshy, should be left out for their cut ends to dry and ‘cauterize’ somewhat before rooting. Many euphorbs behave much like cacti, but are even more hazardous to handle because of their very caustic sap.
The majority of small succulents, like the many jade plants and iceplants, are notoriously easy to propagate by cuttings.
Many species of Agave and Yucca should probably be more popular here than they are. Several are endemic to desert or chaparral climates. Once established locally, they may survive without irrigation. Occasional watering through summer only improves their foliar color and vigor. Except for gophers that might attack from below, not much offends them.
The primary deterrent to their popularity is their dangerous foliar spines. Many species of Agave and Yucca grow too large to not become obtrusive within compact home gardens. Consequently, their striking but hazardous foliage can be difficult to avoid. Fortunately, a few species such as thread agave, Agave filifera, remain proportionate to home gardens.
Thread agave develops rounded foliar rosettes that are less than three feet wide and two feet tall. Evergreen leaves retain silvery impressions of adjacent leaves. Although growth is generally slow, vigorous floral stalks may grow rapidly to ten feet tall during summer, to bloom during autumn. Pups begin to replace original rosettes prior to monocarpic bloom.
Several species of Agave inhabit the landscapes here. Only a few are identified. Some of those that are unidentified could likely be identified if their identities were important to us. For some, identification would be as simple as researching our records. I know what Agave attenuata is only because there is nothing else like it. #3 is likely a variegated and dwarf cultivar of Agave americana. #6 is the surprise of these Six. It is a familiar species that was formerly identified as another genus. Although its relation to the Family should be obvious in regard to physiology, it is not visually similar to others of the Agave genus. I still know it by its older and perhaps less accurate designation. It works for me.
1. Pups of an unidentified agave that was removed last year are a concern because others just like this continue to develop where the agave was relocated from a few years earlier!
2. The parent agave got removed and dumped next to a greenwaste pile after gophers ate its base, but somehow survived. It fell over only recently. Maybe other gophers found it.
3. Gophers also ate the base of this other unidentified agave, which, like the other agave, seems to have survived somehow. Fortunately, it did not leave undesirable pups behind.
4. Agave attenuata arrived as a big cutting with a long stem, and by odd circumstances. The severed stem generated a big secondary rosette, which is now generating four pups.
5. The pup to the lower right of this unidentified agave indicates that its primary rosette may be about bolt and bloom. Although most agaves are monocarpic, their pups survive.
6. Surprise! Fresh from 1985, tuberose, which was formerly Polianthes tuberosa, is now Agave amica. We just installed three, with two more still canned. I hope for many pups.
Things do not always go according to plans. Seasons and weather change faster than we can keep up. Many plants do what they want to do rather than what we want them to do. There is always compromise. It is a bummer that a unique agave is bolting now, and will eventually die, but it provided plenty of pups to replace itself with. It is a bummer that I must remove a productive elderberry bush before the berries ripen, but there are plenty more elsewhere. It is a bummer that two exemplary red maples may have died, but there are three more. The excess of recycled cannas is not a bummer though, but merely extra work.
1. Whale’s tongue agave was a splurge. The horticulturist who got it had been wanting to grow it for a while. However, two years later, it had a litter of pups and is now blooming!
2. The flowers are not even very pretty. At least the floral stalks are weirdly striking, and bloom slowly. Although monocarpic, it could take months for the original rosette to die.
3. Six big potted maples were installed temporarily last year. Three are red maple. Three are Norway maple. The red maples foliated before we made arrangements for irrigation.
4. Elderberries are developing nicely. These are some of the best. However, they are on a big healthy elderberry bush that must be cut back from a roadway before they can ripen.
5. Cannas are fun! I was pleased with an opportunity to recycle a bunch from a neighbor. However, this pile is HUGE! Well, I know what I will be doing this Saturday. Goodness!
6. These cannas bloom very nicely. Most are bright orange. Most of the rest are yellow. A few are red. Unfortunately, they are blooming in the big pile, unseen and unappreciated.
Cacti have thick, fleshy stems outfitted with nasty spines instead of leaves. Agaves and related aloes have stout, fibrous stems that are mostly obscured by thick, fleshy leaves. (Only a few somewhat rare aloes develop bare trunks and stems.) What they have in common is that they all are succulent plants, collectively known as succulents.
There are all sorts of other succulents. Humongous saguaro cactus have hefty trunks and limbs. Diminutive impatiens (like busy Lizzie) are grown as annuals for their colorful and very abundant flowers. Many succulents have succulent stems. Many have succulent leaves. Some, like the common jade plant, have both succulent leaves and stems. Trailing ice plants, leafy begonias, and sculptural euphorbs (related to poinsettias) are all succulents.
Many succulents store water in their succulent parts because they live in dry climates. Because moisture is such a commodity where they live, cacti protect their succulent stems with sharp spines. Agave protect their leaves with sharp teeth. Euphorbs are equipped with caustic sap, and many also have spines like cactus have. Fortunately, most succulents are not so unfriendly.
Almost all succulents are remarkably easy to propagate from cuttings or by division. In the wild, pieces of prickly pear cactus that fall onto the ground will begin to develop roots through the rainy weather of autumn and winter, and be ready to grow into new plants by spring. In the home garden, cactus cuttings should be left out for a week or more so that the cut ends will ‘cauterize’ (Actually, they just dry out a bit.) and be less susceptible to rot once they get plugged into the ground or pots to grow roots. Alternatively, clumping cactus that develop multiple main stems from the base can be divided, although the spines make handling them difficult.
Most aloes and some agaves produce basal shoots known as pups, that can be split from the main plants to grow into new separate plants. Agaves that do not produce pups while young typically start to produce pups after a few (or many) years, as they mature enough to bloom. Many of the larger types produce an abundance of pups after bloom, since the main shoot dies as flowers deteriorate. If desired, one or more of the pups can be left in place or planted back to replace the parent plant.
Most other succulents are even easier to propagate. Small cuttings can be plugged wherever new plants are desired. Some can even be grown from leaf cuttings!
Of the fifty or so known species of Yucca, I formerly grew all but one. I still am not certain if the single species that I lacked, Yucca flexilis, is a real species or a synonym for another species. Of course, some species of Yucca might be considered to be subspecies of others. The genus is complicated. So is identification of its species. That is why I am not certain of the identity of the one Yucca that I got a picture of this week. Actually, only one of my Six, which live with the unidentified Yucca, are identified.
1. ‘Sedums, Dahlias and Hayfever’ might have something to say about this unappreciated mess. A neighbor left these for the gardens. I can identify only that ‘Angelina’ sedum. Oh, the shame!
2. Pups such as this could suggest that the associated primary rosette intends to bloom soon. If so, the pup will replace the original. I do not remember what species or cultivar of Agave this is.
3. This young pup appeared about six feet from its associated primary rosette, so is less likely to be an indication of impending bloom. I do not know the species or cultivar of this Agave either.
4. Agave attenuata is easier to identify. It has been here since December, but has not done much. I got a pup from it prior to planting. Later, another rosette was acquired from another source.
5. This might be Dasylirion wheeleri. I am rather certain of the genus, but not so certain of the species. Those little teeth on the foliar margins remind me that I do not want to weed around it.
6. Could this be Yucca whipplei? Its foliage certainly suggests that it is. However, the common sort should not develop such crowded rosettes. It could be a more densely clumping subspecies.
This is the link for Six on Saturday, for anyone else who would like to participate:
For a tough perennial that is is grown for striking foliage, the smallAgave filifera has a remarkably striking bloom as well. The one and a half inch long flowers are impressive pale green, and mixed with faded flowers. What makes them so compelling is that they are displayed on sculptural floral spikes that stand nearly six feet tall.
Unfortunately, each dense rosette of foliage is monocarpic, which means that it dies after bloom. Pups (sideshoots) sometimes develop as a main rosette deteriorates. If multiple pups develop and get crowded, they can be divided. Each rosette takes a few years to bloom, so should be around for quite a while.
The stiff evergreen leaves get about a foot or a foot and a half long, with unpleasantly sharp tips. Vigorous plants have white filaments that peel from the edges of the leaves. Like all agaves, Agave filifera, does not need much water once established. Unlike other agaves, it can tolerate a slight bit of shade.
Agaves are innately tough and undemanding. The main reason that they are not more popular in home gardens is that they are outfitted with nasty foliar spines. The worst of these spines are the distal tips of the large succulent leaves. Most agaves are also armed with shorter recurved spines on the margins of their leaves. Gardening with such well armed perennials can be dangerous.
A complete lack of foliar spines is what makes Agave attenuata such a deviant. The relatively pliable foliage forms big grayish rosettes that can get as broad and tall as four feet. Groups of these rosettes can slowly cover quite a bit of area. The plump stems below may eventually become exposed as they shed old foliage, but are they usually obscured as newer rosettes develop and grow.
The cultural preferences of Agave attenuata are also somewhat unusual. Unlike other agaves, it wants occasional watering and a slight bit of shade. If too exposed, it can get frosted in winter, or roasted in summer. Agave attenuata is also known as foxtail, lion’s tail or swan’s neck agave because its fluffy yellowish flower stalks curve downward, and maybe up again, to about six feet tall.
After providing remarkably striking foliage for many years, the biggest and boldest agaves bolt with spectacularly tall floral stalks that support horizontal pads of flowers. These stalks can bloom for months, and stand for months after bloom is finished. Then things get ugly. The foliage around each bloom folds back, desiccates and dies. There is no nice way to describe it. Bloom is death.
Plants that bloom only once and then die are ‘monocarpic’. Agaves are not truly monocarpic, since they do not really die completely. They survive by producing pups (offshoots) as their original rosettes of foliage die. Some agaves start to produce pups years prior to bloom, just to be ready. Most terrestrial yuccas (that do not form trunks) go through the same process shortly after bloom.
Pups can be so prolific that they get crowded. Because the larger agaves are so big, they can conquer a significant area with just a few pups. With all their dangerously nasty foliar spines, extra pups are not at all easy to remove. Once removed, pups can be planted elsewhere as new plants, but they will grow up into even more agaves that will eventually bloom and make more pups!
Removal of the carcasses of bloomed yuccas without getting stabbed by the sharply tipped leaves is challenging. Removal of the carcasses of big agaves is hellish! Spines of old foliage never go dull. Pups hiding below the old foliage are just as dangerous. Tall blooms must be cut down like small trees. The debris can not be recycled in green waste, so must be disposed of like trash.
Furcraeas, which are related to agaves and yuccas, produce fewer pups, or may not produce any pups at all. Of course, a bloomed plant without pups will die completely. However, the huge conical blooms (that resemble Christmas trees) produce bulbils, which are tiny new plants that can be plugged back into the garden to grow into new plants! Regardless of all the work, furcraeas, as well as yuccas and agaves (within reason), are worth growing for their dramatic foliage and impressive bloom.