Q. I planted a two-gallon-sized octopus agave in my front yard, where it receives full sun. It receives some filtered shade from a nearby tree but that is during the morning hours. During the month and a half that it’s been in the sunny location, I noticed that some of its leaves were getting red and crispy at the ends. The top leaves were actually starting to split down the middle. Do you know what causes the leaf to split? Should I relocate this plant?
-Anne Marie Darrach, Valencia
A. Your agave is suffering either from too much sun, too much water, or from improper planting depth. My first thought is that it is getting too much sun since foliar sunburn on agaves is not uncommon. This is especially true on soft-leaved species such as octopus agave (Agave vilmoriniana) and foxtail agave (Agave attenuata).
Since your agave is newly planted, it may not have had time to adjust to your microclimate prior to the hot weather we experienced in recent weeks. If your agave was grown in a nursery where the climate was milder than Valencia’s, it could have burned during a single hot afternoon shortly after being planted in your front yard. Agaves, many of which are native to sub-tropical Mexican deserts that are less harsh than deserts of the American Southwest, benefit from afternoon sun protection when they are planted in the hot interior valleys north and east of Los Angeles.
Another matter of concern is water. Agaves must have fast-draining soil or they may develop burned and split leaves, the result of soil fungus. These symptoms may also be brought on by deep planting. Make sure the top of the root ball is even with or slightly above the soil surface. Take care not to moisten agave leaves when watering since this can lead to foliar fungus problems.
The octopus agave, with long and tentacled leaves, has been gaining in popularity as lush or brightly colored tropical plants give way to sculptural and drought-tolerant ones. The only caveat on planting agaves is their short lifespan of five to 25 years. Agaves are monocarpic, meaning they flower and fruit only once, just before they die.
The genus name Agave is derived from a Greek word meaning “noble,” and both the appearance and biology of agave species possess noble aspects. Many species, those that grow no more than a foot or two in height, have the appearance of royal crowns and two are named after a queen (Agave victoria-regina) and a king (Agave fernandis-regis).
Agaves also display nobility in sacrificing themselves for the next generation as they throw all their energy into the flowering, fruiting and seed-producing process, so much so that nothing is left over for their own growth and they die. Agave flower production may be a spectacular sight, as in the case of the classic and largest agave, known as century plant (Agave americana), which raises up a 30-foot flower stalk prior to its demise. Note: century plants seldom live longer than 25 years.
Agave mother plants, by the time they die, will typically have produced a number of offspring alongside, so-called pups that grow from rhizomes of the mother plant. The octopus agave, however, does not produce pups. Instead, it produces hundreds of bulbil clones on its reproductive stalk.
Along with maize and potatoes, agaves were a pillar of the economies of the Aztec and Mayan peoples. Agaves were utilized for food and drink, as well as in the manufacture of soap, textiles and clothing, red dye, needles, medicines, and fencing.
One of the agave’s most unusual relatives is the ponytail palm, a prize specimen of which is growing at the northeast corner of the Laurel Canyon and Ventura Boulevard intersection in Studio City. Owing to the swollen base of its trunk, this exotic-looking species (Beaucarnea or Nolina recurvata) is also known as bottle palm or elephant-foot tree.
The Studio City ponytail palm, which seems terribly stressed at times, will not strike you as beautiful. Its glory is in its unique appearance and remarkable staying power. Its swollen trunk stores water so that it can go for months, if not years, without irrigation. When thriving, its leaves can reach five feet in length while remaining no more than 3/4 of an inch wide. The leaves hang down on all sides of a branch, producing its ponytail look.
Ponytail palm can grow in almost any exposure, as long as its soil drains well. Mature specimens survive a frost. It can take considerable sun, a fair amount of shade and makes an excellent container plant as well.
Another fascinating agave relation is the seldom seen, but never forgotten, monocarpic, Macdougal century plant (Furcraea macdougalii). It eventually grows a trunk up to 25-feet tall but, throughout its development, exhibits a rosette of highly symmetrical and elongated leaves, conferring it the status of an incomparable accent plant, riveting your attention like few others. Mauritius hemp (Furcraea foetida ‘Mediopicta’) is a stunning agave lookalike, except that its leaves have glimmering yellow stripes and undersides.
Two local sources for agaves and their relatives are World Wide Exotics in Lake View Terrace and California Nursery Specialties in Reseda. A few Macdougal century plants are available at Jurassic Garden in North Hollywood.