Last week, we were repotting our container agaves prior to winter, when we ran up on this unusual sight. Let me begin by explaining that there are three groups of agaves, based on how they propagate: solitary agaves, rhizomatous agaves, and offsetting agaves. While it’s not unusual for a rhizomatous agave to produce an underground shoot in container, this level of underground shoots is highly unusual. What is even stranger is that this is a non-rhizomatous cultivar.
Since some agaves are poor or non-offsetters, the only way to force them to multiply is to remove the apical bud, either by means of coring, or drilling. Once this is done, the agave usually forms offsets in the remaining leaf axils. For some reason, when this plant of Agave ‘Ripple Effect’ was cored, it went nuts by developing underground rhizomes.
Left to its own devices, there will be one plant produced from the growing tip of each rhizome. There is, however, a dormant bud every few inches along the rhizome, so in theory, this could produce hundreds of plants if we can figure out how to make the dormant buds break. Below are the shoots after we unwound the twisty rhizomes.
As fall temperatures drop, it’s not unusual to find our native bees asleep in some of the most interesting places. We caught this carpenter bee fast asleep on the job this week, clinging tightly to the spines of an Agave parryi.
Our 2016 century plant hybrid is looking quite lovely in the garden this month. This plant, which we named Agave x victorifolia ‘Prince of Whales’, is a hybrid of the Whale’s tongue century plant, Agave ovatifolia (male parent), and the Queen Victoria century plant, Agave victoriae-reginae (female parent).
Since both parents are non-offsetting, this means that the offspring will grow to maturity, flower, then die. Consequently, in order to be able to propagate and share, we will have to drill out the central core of the plant to trick in to offset. While this ruins the appearance of the original, it’s the only way for this to ever be shared and preserved. This plant has been in the ground since 2018, so we expect to have another eight years (guessing) prior to flowering. Consequently, so we’ll probably gamble on waiting a few more years before performing surgery. Winter hardiness is Zone 7b-10b.
We love the spineless Agave bracteosa ‘Stingray’ in the garden. We’ve had these dotted throughout the garden since 2017, and so far, with good drainage, they’ve handled our winters quite well, which is certainly not normal for a variegated century plant. This particular species prefers part sun to light shade. Hardiness is Zone 7b/8a and warmer.
Looking lovely today is the amazing Agave x romanii ‘Shadow Dancer’. This fascinating agave is a man-made hybrid between two Mexican species, Agave filifera and Agave mitis. Not only is it a hybrid, but this selection has a fascinating variegation pattern that’s not seen on any other century plant. The new growth emerges ghostly cream with a muted green border. As the leaves age, they green disappears and the leaves become pure parchment white. Despite the seeming lack of chlorophyll, Agave ‘Shadow Dancer’ has amazingly good vigor and doesn’t burn in full sun. This has potential winter hardiness for Zones 8b and south, but needs more trialing to know for sure. In other climates, it’s a great container specimen.
A few weeks ago, we posted images of the flower spike of our Agave ovatifolia ‘Vanzie’ just beginning to spike. Now, the giant beast is in full flower. The first photo below is the plant with its full expanded stalk in full bud, just prior to opening. After that, each image shows the progression of the flower development.
Agaves are monocarpic, so those species like Agave ovatifolia that do not make offsets will die after flowering. Agave ovatifolia is, however, one of a handful of species that usually forms baby plantlets on the tip of flowers stalk after seed set.
First flowers just beginning to open
We set up our Little Giant ladder, which allows us to climb up, collect pollen and to make crosses with other agaves.
The lower flower clusters open first and flowering continues to progress each day moving higher up the stalk.
Climbing the ladder gives you a bird’s eye view of the amazing buds as they are ready to open…usually 200-300 per panicle.
Below is a half-open flower panicle. The pollen is ripe before the stigma is ready to receive pollen, so pollen can be easily gathered without worry of self pollination.
Below is a fully open flower panicle. Each panicle weighs 5-10 pounds. No wonder the stalk needs to be so sturdy. Once the temperature warms in the morning, the flowers are abuzz with pollinators…mostly bees.
Looking down from above the flower panicle makes a pretty crazy photo
Our intern Zoe is working with our volunteer agave curator, Vince Schneider to gather pollen and make crosses with other previously gathered agave pollen
I usually don’t climb this high…a fear of heights, but this photo opportunity was just too good to resist
In case you missed this section of the garden during spring open house, this is where we created a small vignette that comprises both bog and desert conditions in the same space. The low central area was created for pitcher plants and other bog lovers, while the higher areas to each side, are home to dryland loving plants like agaves and bearded iris. We hope to show how dramatically diverse habits can be created in a very small space. The wet space is created by installing a seep, which is nothing more than a continually dripping water line.
Just over a year ago, we built a new berm garden, adjacent to our Open House welcome tent. Here is that garden today. The soil is composed of 50% Permatill (slate gravel), 25% compost, and 25% native soil). This is in an unirrigated section of the garden. Like all garden spaces at JLBG, no commercial fertilizers are ever allowed. The exceptional drainage and high nutrient content from the compost and Permatill result in an amazing growth rate.
If you’re able to visit during this years spring open house, it will be hard to miss the look of love in the air. We have a record 20 century plants in spike in the garden…a number far surpassing any flowering record we’ve set previously.
Agaves are a genus of mostly monocarpic plants…they live their entire lives to flower once, then after experiencing a giant-sized orgasm, they fall over dead. In the wild, many species take up to 100 years to flower, which is why the name century plant stuck as a common name. In our more rainy climate, our century plants typically flower in 12-15 years. Several of our current crop are actually less than a decade old, but their enormous size has already been achieved, so they’re ready to reproduce.
Some species of agaves offset, and in this case, only then central rosette dies, and the offsets continue as is the case with bromeliads. Those agave species which never offset are one-and-dones, but hopefully will leave behind a plethora of seed for the next generation. From the start of the spikes to full flower is usually about 8 weeks. Below are a few of our babies in spike.
We’ve “enjoyed” frozen precipitation for three consecutive weekends this winter, with one producing a decent 3.5″ snow. There’s something magnetic about snow on century plants, that makes you grab your camera and snap away.
The white of the snow looks out of place on an agave, although it does wonders for accenting the architectural structure of the plant. We have worked for 35 years to identify and create agaves which are completely tolerant of such weather events. Below are a couple of our hybrids, created here at JLBG.
Since we’ve been growing agaves, one of the most fascinating things we’ve noticed is the incredible attraction of tree frogs and Carolina anoles to their leaf texture. There is hardly a day that goes by that we don’t spot one or the other, nestled on an agave leaf. Here is our most recent image of our native green tree frog, Hyla cinerea, basking in the sun on an Agave parryi hybrid. Ain’t nature grand!
It’s always interesting when we introduce a plant we think is an incredible addition to the garden, but virtually no one purchases it. Thank goodness, it doesn’t happen too often, but I’m reminded of one such case every day when I get home and admire our row of Agave x striateosa ‘Straight and Narrow’. This 2015 introduction was the first ever hybrid introduction of Agave bracteosa and Agave striata…both non-spiny century plants.
We couldn’t stand to throw out all the plants that didn’t sell, so we planted a row under a wide overhang along our home, where they never see any water, and are in shade for more than half the day. Here is one of those plants five years later, providing a texture and form that you simply can’t find with any other plants that tolerates those conditions.
We have a second seedling from the same cross, which we’ve never been able to share, but which flowered in 2015. Despite our best attempts, we were not able to get any seed set. Now, we await the first flowering of this clone in the hopes it is more fertile, so we can create some more unusual hybrids. Unlike most century plants, Agave striata is not monocarpic (doesn’t die after flowering), so we expect this hybrid to also live on in perpetuity after flowering. Winter hardiness is Zone 7b-10, at least.
One of our favorite winter hardy (Zone 7b) century plants is the non-spiny Agave bracteosa ‘Stingray’. Here is one of our garden specimens this week, which has been thriving in the ground since 2016. Unlike most agaves, which prefer full sun, Agave bracteosa is better in part sun (full sun for only a few hours during the day). Agave bracteosa ‘Stingray’ is also a fairly slow grower that only produces a few offsets. A mature rosette will top out around 15-18″ tall x 2′ wide. We love the unique texture, which differs from all other agaves.
One of many great attributes of mangaves, compared to one of their parents, agaves, is that they don’t die after flowering. Agaves are mostly monocarpic, which mean that they behave like bromeliads, where each rosette grows to maturity, then dies after flowering. Those species of agave which offset, live on after flowering, by means of un-flowered offsets. Those agave species which don’t offset are a one and done after they flower and reproduce by reseeding.
By incorporating manfreda genes to create xMangaves, the monocarpic trait disappears. After a mangave flowers, it dies to the ground, but like a good zombie, it soon pops back from the dead. Here is a current photo from the garden of two clumps of xMangave ‘Blue Mammoth’. The first, larger clump has not flowered, but should do so next year. The second clump with all the offsets, flowered in 2020, and re-grew to this point in 2021. Next year, the rosettes will continue to re-grow in size.
We’ve been working on upgrading many of the temporary gates throughout the garden, our first few, which went in this year are all designed by NC sculptor Jim Gallucci, from photos we took in the JLBG Gardens. We all need more art in our gardens…Enjoy!
I was fascinated to find these monarch butterfly chrysalis’s hanging out on an agave in the crevice garden recently. Our entomologist, Bill Reynolds, tells me that when the caterpillars are finished feeding, they will often migrate from a nearby asclepias to all kinds of odd plants to hangout until it’s time to come out of their closet. It’s hard to imagine a full-size monarch butterfly inside these little structures, but perhaps they are like Dr. Who’s Tardis.
Since we are limited in the number of hardy century plant species, our only option for more agave diversity in the garden is to create it by crossing existing hardy species together. Here are a few of our recent successes.
Agave x amourifolia is a Plant Delights/JLBG creation from a cross we made in 2016 that combined the genes of three century plants, Agave ovatifolia, Agave lophantha, and Agave x pseudoferox ‘Logan Calhoun’. Our size estimates were that the offspring would mature at 3′ tall x 5′ wide. Here is one of our garden specimens photographed this week, which has already reached 2′ tall x 3′ wide.
Below is Agave x ovox, a 2017 cross of the two giants, Agave ovatifolia and Agave x pseudoferox ‘Bellville’. We expect this to get huge…perhaps 5′ tall x 10′ wide.
Below is Agave x protifolia is a 2016 Mike Papay cross of Agave x protamericana x Agave ovatifolia. We also expect this to get quite massive.
Below is Agave x ovatispina ‘Blue Arrows’, a 2016 Mike Papay cross of Agave ovatifolia x Agave flexispina. We would have expected this to be a mature size, but it’s achieved this in only 5 years, so we think we’re seeing some serious hybrid vigor.
Below is Agave x ocareginae, our 2016 cross of Agave ovatifolia x Agave victoriae-reginae. Most likely, this elegant small grower will never offset.
Below is Agave x schuphantha, a 2015 Mike Papay cross involving three century plant species, Agave schidigera, Agave lophantha, and Agave lechuguilla. It’s formed a beautiful, symmentrical rosette, which should be getting close to mature size.
As a plant breeder, one of the cool things we get to do is observe the diversity that arises from a single cross. In some cases, the diversity shows up in the first generation (F1), while in other cases, the first set of offspring need to have sex with each other for the diversity in the offspring to reveal itself (Mendelian genetics). Fortunately, with agaves, we can see quite a bit of diversity in the F1 populations.
Below is a cross we call Agave x amourifolia, which is our cross of Agave ovatifolia, pseudoferox (salmiana var. ferox of Hort.), and lophantha. Here are three of our selected seedlings from that cross.
Plant #1 below is showing the large size of Agave x pseudoferox and the color of Agave ovatifolia (blue), with little visible influence of the narrow leaf, yellow-centered Agave lophantha.
Plant #2 below show more color influence from Agave x pseudoferox, but with the compact form influence of Agave ovatifolia.
Plant #3 below shows equal parts Agave x pseudoferox and ovatifolia, but also, what appears some leaf narrowing we would expect from Agave lophantha.
Below is Agave x flexiferox, created from a cross of the small Agave flexispina x the giant pseudoferox (salmiana var. ferox (Hort.). Plant #1 shows the small size of Agave flexispina, with the greenish coloration of Agave x pseudoferox.
Below, Agave x flexiferox ‘Megalodon’ shows the larger size and overall coloration from Agave x pseudoferox, with some added blue tones from Agave flexispina.
Below is Agave x victoferox, a cross of Agave victoriae-reginae x pseudoferox. Plant #1 below shows the form and size of Agave victoriae-reginae with the color of Agave x psedoferox.
Hybrid #2 below shows the teeth from Agave x psedoferox (victoriae-reginae has no teeth), and a size intermediate between the two parents.
Hybrid #3 below shows a larger size and more teeth due to more genes from Agave x pseudoferox. The teeth are much smaller because of the Agave victoriae-reginae genes. The splendid compact form also comes from the Agave x victoriae-reginae parent. This cross almost resembles the Northern Mexican Agave montana.
We hope this gives you a small peek into the world of plant breeding and the subsequent evaluation and selection process.
This summer, two of our spiking clumps of Agave ovatifolia became dislodged from the ground during a violent thunderstorm. We wondered if they would still set viable seed despite being without roots, since the energy built up from 15 years of growth was still in the foliage. We made several crosses without having to set up a ladder and it appears that we’ve got good seed set. Nature is amazingly in its desire to survive.
Agave x striphantha ‘Striptease’ is a JLBG creation from a 2013 cross of Agave striata and Agave lophantha. Both parents are 30 year survivors here in the garden, so we wanted to see what a combination of genes looked like. Also, Agave striata is the only hardy agave species, whose main crown doesn’t die after flowering. So far, this gem is 3′ wide, and like the Agave striata parent, it offsets from the crown and doesn’t sucker like Agave lophantha. It’s looking like a flower spike may be imminent, so perhaps we’ll have our flowering question answered soon.
We posted this a few weeks ago as our Agave ‘Mountain Man’ (A. gentryi x montana) prepared to open. We’ll, the big moment is here…below are a few shot from today.
The seed were wild-collected in Mexico in the late 1990s by our friends at Yucca Do, and our seedling was planted in May 2000, so it took 17 years to flower. Fingers crossed for good seed set, and fortunately we have many more agaves in flower (and a tall ladder) to help the process.