Posted on by tonytomeo

Monocarpic?

Agaves refuse to die.

Monocarpic species bloom only once. They die afterward. Many annuals are monocarpic by default. After bloom and production of seed, they have served their purpose of perpetuating the next generation. Some may bloom more than once within their respective season, but realistically, do not expect to live for long after doing so.

Agaves are monocarpic. Unlike annuals, some grow for many years before maturing enough to bloom. In fact, the century plant is known as such because, in the wild, it supposedly takes a century to mature enough to bloom and finally die. Of course, they do not take nearly so long to bloom within cultivation.

That could be either an advantage or a disadvantage. Their bloom is awesome, but their death is ugly. Removal of their deteriorating but wickedly thorny foliage is a horrid chore. The sap from their foliage causes a rash that can be comparable to the allergic reaction from poison oak. What is worse is that they are not really monocarpic!

Again, that can be either an advantage or a disadvantage. They provide more than enough pups to replace their deteriorating carcass. However, these prolific pups must be divided from each other and the deteriorating carcass of their parent. They are too numerous to accommodate within the same garden or share with neighbors who likely do not want them. Furthermore, they continue to generate pups long after the parent and first litter of pups is gone. Without intervention, they seem to never die completely. Even with diligent intervention, they can linger for many years.

This particular agave should have remained vegetative for many years, but bloomed after only two or three years. The first litter of pups bloomed immediately afterward, as this picture demonstrates. Ultimately, we would like only a single pup to replace the parent.

Posted on by tonytomeo

Agave filifera

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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.

Posted on by tonytomeo · 2 Comments

Spectacular Bloom Can Be Lethal

70510thumbAfter 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.