Agave are called century plants because it takes them many years to get big enough to have the energy to flower. It was once believed that it took a century. Not quite. Some can bloom after a mere decade. Especially when several hot dry summers in a row are followed by what is supposed to be a wet one (Here’s hoping for a wet Southwest summer in 2026).

Let’s look at why.

Agave is a Shrub

In landscaping (and in the science of Biogeography) agaves are considered shrubs. They are shorter than trees, sort of a mid-level plant – although some are quite small. Basically they fill the niche of shrubs in the landscape.

Agaves may be shrub in size, but when they bloom, they send up a flower stalk that can be far taller than desert trees. This tall flower stalk is because they are pollinated by bats and they need to get their flowers way up in the sky for bats to find.

When you are a desert plant living in typical desert, it takes a number of years to create and store enough energy to shoot a flower stalk way up in the sky. Not to mention then to make enough nectar and pollen rich flowers to attract flying warm blooded mammals.

Agave is a Rosette Shrub

Rosette is a just a little rose = rosette. A rosette forms the center of that fancy ribbon you might win in certain competitions. That rosette shape is the central shape for an agave.

Many other plants in the same family and closely related families share this rosette nature. It’s an easy form for DNA to code for. Family members include yucca, and aloe. Close kin include lily (think daylily not Easter lily), palms, even the plant that pineapple fruit grow on (bromeliad). Some rosette plants stay small, like lilies, but some get treelike – like palms and tree aloe.

Agave is a Monocot Rosette Shrub

Here’s another term that looks complicated but you already know half of it. Mono = one. Also uni = one. We are looking at Greek and Latin. We call them unicycle, bicycle, and tricycle (Latin), but if life had been a bit different they would be monocycle, dicycle, and tricycle (Greek).

Monocot is short for monocotyledon. A cotyledon is a seed leaf. Most plants have either one or two seed leaves. Monocot or dicot is a major division in the plant kingdom. This division is useful for people classifying plants – but also for people taking care of plants. If you want your monocot rosette palm that graces your landscape to live for many years, you need to take care of them differently than if it was a dicot non-rosette tree.

Just to round out the story, there are some ancient plants that have many seed leaves, like pine, gingko, and cycad.

Rosette plants are monocots. It’s in their DNA. There are nonrosette monocots but no nonmonocot rosette plants. Unless you look deep into cellular anatomy, which we are not doing here.

Agave are Monocarpic

Here’s that mono again. Means “one” “carpic” – but what the heck is carpic?! It’s an ancient Greek word for fruit or grain. Not that the plant has only one single fruit – but that is produces fruit only one time in it’s life.

Monocarpic plants will flower, set seeds and then die. The opposite of one is many or poly. Polycarpic plants flower and set seeds many times during their lifetime. Our lovely spring annual wildflowers are monocarpic. Rose bushes are polycarpic.

In the Southwestern deserts and uplands we have yucca and agave, both iconic monocot rosette shrubs. Yucca plants flower more than once in their lifetime. They are polycarpic. Agave flower once and then die. They are monocarpic.

Mono carpic doesn’t mean only one single flower. Monocarpic is a single flowering event. Agave produce hundreds or even thousands of flowers!

Side Note. Along with agave, there are a number of species of bamboo that are monocarpic, which is of concern when whole forests of bamboo all flower at once and die. Panda rely on bamboo for food. When your entire forest of food dies – what happens to you as a species?! But I digress.

Desert Life is Hard

So back to native Southwestern plants. The monocarpic agave blooms once it is big enough and strong enough. They put everything they have saved their entire life into flowering and thus ending their life. But what about the polycarpic yucca? Can they flower every year? Polycarpic rose bushes living in less harsh climate certainly flower every year.

To answer this question I share the words of a person who raises yucca and agave for a living. Plantsman extrodinaire Jan Emming is the author of the second half of this post. He writes about the flowering habits of the rosette plants that inhabit our Southwestern world. I have edited it somewhat for non-plant nerds to follow.

Yucca Flower Cycles

“Most yuccas skip anywhere from 2 to 4 years in between flowerings on individual heads. This is because yucca die just a little when they flower. Technically, the terminal growth points of yuccas die during the process of blooming and they need to develop new side shoots in order to resume growth and eventually flower again. Typically those new heads have to grow for at least one full season before flowering again, and many of the slower growing yuccas require several years.

The act of flowering often encourages branching, but not always. Some faster-growing “tropical yuccas” (from warm and wet climates) can flower annually out of their new heads. Most of the slower-growing “desert yuccas” (dry climates) take a minimum of 2 years, and many take 4 to 5 years to bloom again.

While a given head might not flower again for 2-4 years that doesn’t mean another head or branch elsewhere on the plant (if it has them) can’t bloom the next year if it’s large enough to do so. Thus, many yucca clumps or multi-branched specimens might flower annually, albeit on different stems or heads from the prior year.

Monocots Vary

Aloe

Compare this terminal flowering pattern of yuccas to that of other monocots. For example the African aloes produce flower spikes out of side buds, a cellular division process that does not kill the terminal growth point. This means that aloes can easily bloom annually, and many species can readily produce multiple flower spikes per year, whether in sequence or all at once, because they don’t need to replace their growth tips. They are using lateral side buds, a process called axial flowering. (More on aloes and tree aloes on my YouTube)

Agave

By contrast agaves flower terminally, from the center.  Almost all species (with only a handful of exceptions) die after flowering and setting seed. While many agaves have pups that continue to grow after the main mother rosette dies, once a given rosette blooms that is it and that particular head will not continue to survive even if it has pups surrounding it that might replace it over time.”

Editors Note.

Many agaves do produce side pups before doing their final blooming. They hedge their bets on survival of their genes. If you rely on seed alone to spread our genes, you may die out of the gene pool.

 

Agave pups are useful if you are a nursery that wants many plants to sell, but can be frustrating as a homeowner when they start pupping all over and taking over your yard. The solution to this issue is to water less.

Pupping can be a good thing for both ancient and modern farmers. One species of agave that pups readily, Agave murpheyi was cultivated by the Hohokam for food, another is the agave that is used to make tequila.

Back to Jan’s discussion.

Bromeliad

Both pineapple and Spanish moss are in the bromeliad family.

“There are tropical monocots worth mentioning in this discussion on flowering. The bromeliad family has members that exhibit both types of blooming characteristics depending upon species. Some are monocarpic terminal bloomers where the flowering rosette dies afterwards, while others are polycarpic and flower more than once, like the yuccas do. In the family, most bromeliad genera flower terminally like the yuccas, while others flower axially like the aloes.

Palms

Most palms are polycarpic and flower axially as well.  They can flower every year and give us fruit like dates.  There are a few species of monocarpic palms that flower terminally and die after producing only one flower show in their entire lifetime.

I (Jan) hope this will help readers understand the differences in growth habits and flowering patterns in the various monocot plants that might be in your garden or plant collection.

Monocarpy is Everywhere

Monocarpic flowering is found in many plants – including dicot plants. For example – annual plants. Annuals naturally survive only a few weeks or months, flower one time, and then die before a full year (annular cycle) has passed. We usually call them annuals, but they can also be called monocarpic.

Monocarpic dicots that live for two years include certain garden vegetables such as beets and carrots. These usually live for two years, a lifestyle commonly called biennial. They live their first year as non-flowering plants, overwinter once, and then flower their second summer and die afterwards, making them monocarpic biennials.  (We humans dig up and eat the tasty roots where they are storing the sugars for their flowering event.)

There are also monocarpic perennial dicots, such as certain succulents popular for rock gardens. Hen-and-chicks which live for multiple years as leaf rosettes that do not flower. When the time comes they bloom once and perish.”

Whew!

Was all this botany too much? Don’t worry, most of my writing is not this technical. For example, have fun with this pretty little flowering monocot – and a cousin of yucca – rain lilies!   In my yard they bloom reliably all summer, every summer. They are supposed to be bee pollinated but the hummingbirds will visit them.

Peace,
Jacqueline

About our Guest

Jan Emming lives in the midst of the desert at “Forever Ranch and Gardens,” outside Yucca Arizona.  His website is his name. 

More Garden Basics and Care

The Month By Month Guide offers tips for all of your landscape plants (yes even lawns and roses) in every month of the year. It is also filled with tips for planning your gardening month and garden design in general.   I have a few copies left and am offering them to you – my loyal readers.

From the review:

“A great reference book is key to successful gardening in the region where you live. Arizona, Nevada & New Mexico Month-by-Month Gardening takes the guesswork out of gardening for anyone residing in the Southwest. With this book, you’ll know what to do each month to enjoy a thriving garden all year, from January to December. Chronologically organized, this guide is full of critical gardening when-to and how-to advice, along with illustrated step-by-step instructions.

The book’s author is Jacqueline Soule, a Tucson-based gardening expert. She knows this arid region inside and out, and she’s written several articles and books packed with her gardening advice. Arizona, Nevada & New Mexico Month-by-Month Gardening showcases Soule’s expertise in one easy-to-read guide.”

Profits from the sale of this book go to the Horticulture Therapy non-profit Tierra del Sol Institute. 

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