Agave filifera

Foliage is better than bloom, and lasts longer.

For a tough perennial that is is grown for striking foliage, the small Agave 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.

Barrel Cactus

Barrel cactus spines are serious business!

‘Echino’ translates to ‘spiny’; so the genus name of barrel cactus, Echinocactus grusonii, means ‘spiny cactus’. Duh! The nearly spherical and furrowed (ribbed) plants are completely covered with stout and dangerously sharp spines. The most popular variety, known as golden barrel cactus, has pale amber yellow spines. Another variety has white spines. Tan or ruddy spines are rare.

Growth is quite slow. It takes many years for plants to get to three feet tall. Only plants that are quite mature bloom in spring or early summer with bright yellow or orange flowers that develop in a circle, like a halo around the top of the plant. Pink or red flowers are rare. Old plants typically develop a few pups (side-shoots), which may likewise take many years to bloom.

Like most cacti, barrel cactus wants a warm and very sunny location, and very well drained soil. If they do not get watered too much, they can stay potted for many years. However, because they are so nasty, they are not too welcome on porches or patios where most potted plants live. Because they are so heavy and difficult to handle, they are not as portable as they should be.

Cacti Have Bite Without Bark

Cacti exhibit unique and striking form.

The most inhospitable spots in the garden that no one wants to put any work into seem to be the domain of cacti, whether or not any cacti actually live there. “Oh, I will just put some cactus there!” is cliché in regard to shadeless and dry spots that get too hot with glare from a south-facing wall. Yet, such spots typically continue to be neglected, and the cactus never get planted.

Why are such distinctive and interesting plants considered to be so lowly that they should be banished to the badlands? Why should they be expected to endure what not other plants are expected to endure? After all, there are so many other distinctive xeric plants, like yuccas, agaves and some aloes, that are just as resilient, and according to some, just as lowly.

Cacti really are not as independent as commonly believed. New plants should actually get watered occasionally until they disperse their roots. If they get watered regularly, they need coarse soil that drains very well. Cactus plants that were grown in sheltered spots really can get scaled if planted where they are too harshly exposed during hot weather.

The main problem with cactus is their nasty spines. Simply planting small plants without getting poked is a challenge. Moving big potted specimens or removing overgrown cactus plants without getting seriously perforated can be daunting. So, even though they might do well in the harsh exposure at the curb, they do not belong in such a high traffic area.

Without foliage or conventional stems, cactus are either awkward to prune, or can not be pruned at all. Barrel cactus have only one or very few round stems. If one of these stems gets to wide, it can not be pruned back. Prickly pear cactus is easier to accommodate only because it has enough stems to spare those that grow out of bounds.

What makes cacti so excellent is their distinctive form. Some have strictly upright stems that resemble those of the organ pipe cactus. Some grow as clumps of short and fat stems. Others grow upward and outward with rounded and flat stems like those of the beaver tail cactus.

Queen Victoria Agave

80425Although a relatively small agave, the Queen Victoria agave, Agave victoriae-reginae, is also one of the most striking. Mature plants form dense foliar rosettes that are between only a foot, and a foot and a half tall and wide. What is so striking about them is the abundance of stout succulent leaves that can be so densely set that some older plants look like big, round and green pine cones.

Genetic variability within the species is considerable though; so not all plants will be so well rounded. Some resemble dark green aloes while young. All are adorned with distinctive white stripes on leaf margins, and wherever the leaves were touching the margins of other leaves before they unfurled. At least one cultivar is also variegated with white, and another is variegated with yellow.

Queen Victoria agave is bold either in the ground or in a large pot. Wherever it goes, it wants full sun exposure, and should be out of the way. The terminal foliar spines are very sharp! It does not need much water, but prefers occasional watering. Old rosettes might bloom with tiny pale white flowers on dramatic three or four foot tall spikes, but then die as they get replaced by basal pups.

Spanish Bayonet

P71110From a simple picture, Spanish bayonet, Yucca aloifolia, is indistinguishable from the common giant yucca. The narrow leaves are about two feet long, and flare upward and outward from terminal buds. Plump conical trusses of waxy white flowers with purplish highlights stand vertically just above the foliage. The main difference is that the leaves are more rigid than they appear to be, with nastily sharp terminal spines.

The second most obvious difference becomes apparent as the trunks mature. These trunks get only about four inches wide, which is not quite stout enough to support their own weight. Some might get taller than ten feet, but eventually fall over. Terminal buds of fallen trunks curve upward, and try to grow vertically again. If not pruned away, old foliage browns and lays back against the trunks, like the beards of fan palms.

Yuccas (reblogged)


P71022+Yuccas are almost as useful as aloes are for gardening in chaparral or desert climates. I say ‘almost’ because most are not quite as friendly. The leaves are outfitted with nastily sharp tips. It is how they protect themselves from grazing animals in the wild, but it is not such an advantage in home gardens. Some actually have the potential to be dangerous where someone could bump into them. The leaves of Joshua tree can puncture leather. Some types of yucca get so big that they make it difficult to avoid their nasty leaves, even if planted in the background.

That being said, for those of us who do not need to worry about endangering children, dogs or anyone else out in our gardens, yuccas are very distinctive and handsome plants. Their striking foliage radiates outward from dense foliar rosettes. Large spikes of creamy white flowers that bloom in summer or autumn stand above the foliage quite boldly. Some yuccas produce remarkably tall floral spikes. Our Lord’s Candle, Yucca whipplei (Hesperoyucca whipplei), is a terrestrial yucca that sits low to the ground, but produces a huge flower stalk that stands ten feet tall! Modern garden varieties of Adam’s needle, Yucca filamentosa, are variegated.

Of the yuccas that develop sculptural trunks, only a few are available in nurseries. The giant yucca, Yucca elephantipes, is almost too common in mild climates, and unfortunately develops a massively distended trunk that is too big for some of the situations it gets into. Most other trunk forming yuccas that grow slower are uncommon because they are susceptible to rot in landscapes where they get watered through summer.

Except for a few tropical yuccas that are very rare, yuccas are very drought tolerant. Even in desert climates, some yuccas survive on annual rainfall. Others are happier if watered a few times through summer. Giant yucca happens to be a tropical yucca, but surprisingly does not need much water.

Giant yucca is very easy to propagate from cuttings of the big canes. Even big pieces can be cut and stuck as cuttings. However, most of the tree yuccas are difficult to propagate.

Terrestrial yuccas that do not develop trunks are generally easy to propagate by division of pups, although some are difficult to handle. Some terrestrial yuccas actually develop small trunks that creep along the ground, or maybe stand a few feet tall. They can be propagated as cuttings like giant yucca.


Aloes (and a Rant)

P71020We really should be growing more of what grows well here. This is as relevant in other regions as it is in the Santa Clara Valley. Some regions have a lot more to choose from. There are always limitations too. Tropical plants do not survive the winters of New England. Apples and pears want more winter chill than they can get in San Diego.

In California, we do not have enough water to go around. Well, that is not completely true. Much of that misconception is political, which is none of my business. Much of it is that there are just too many people living here and sharing a limited resource. Much of it is that many of the too many people living here waste water on, among other things, gardening.

Many of the urban areas of California are in chaparral climates, which means that there is not much rain. Los Angeles and some other urban areas are full blown desert, which means that rain is quite minimal. My former neighborhood in the western Santa Clara Valley got about a foot of rainfall annually. It was considered to be chaparral. Trona, in the Mojave Desert, gets about four inches of rain annually.

However, few people in chaparral or desert regions landscape their homes accordingly. Some limit their ornamental plants to natives. Others limit their choices to plants from chaparral or desert climates, even if not native. Yet, most of us grow plants and lawns that really have no business in chaparrals or deserts, and we do so excessively.

Well, enough of that rant. There are many plants that really should be more popular here.

Aloes are a perfect example. Although many are from more tropical climates, most do not need to be watered too much. Some prefer minimal watering through summer. After winter rains, they produce fresh new succulent foliage in spring, and bloom reliably. Many have flashy orange or yellow flowers on striking vertical spikes. As plants grow, superfluous shoots can be separated and planted wherever more of the same plants are desired.

Smaller aloes are quite dense and mounding, with tight rosettes of stout leaves. Larger types with more open growth can get six feet tall. A few grow into small trees, with thick trunks that might be distended or buttressed at ground level. Leaves might have pronounced teeth along the margins, and most are spotted to some degree.

Everything about aloes is striking. They have prominent and colorful bloom. The distinctive succulent foliage is bold and unique. The larger aloes even have sculptural form.

Aloes are ideal for planters and pots because their roots are so complaisant and undemanding. They are rarely bothered by insects or disease. They are so easy to propagate that cuttings or pups can be acquired from friends or neighbors who are already growing them.