So Long Sotols…In the Spirit of Plant Extinction

We’ve long been enamored with the Southwest native genus of slow-growing woody lilies belonging to the genus, Dasylirion. Since the early 1990s, we’ve been growing these, trialing as many species as we could obtain to see how well they adapted to our climate here in the colder, wetter Southeast.

Image of Dasylirion wheeleri in situ, Payson, Arizona
Dasylirion wheeleri in situ, Payson, Arizona

So, far, we have grown 16 of the 21 recognized species and succeeded with 12. We found four unable to survive our coldest winters, including Dasylirion durangensis, Dasylirion longissimum, Dasylirion lucidum, Dasylirion sereke.

The five species we have yet to try in the garden are Dasylirion graminifolium, Dasylirion longistylum, Dasylirion micropterum, Dasylirion palaciosii, and Dasylirion simplex. We have seed planted of both Dasylirion graminfolium and micropterum, so those will be next in line for our in ground trials. That leaves us still searching for seed of the final three.

Sotols, like agaves, are members of the Asparagus family. They are becoming wildly popular, but not because of gardeners. Instead, their popularity is driven by those who are driven by a need/desire to imbibe alcoholic spirits. First, there was Mescal, a Mexican drink made from one of a number of different agave species, depending on what grew in proximity to each village. Of the Mescals, the most popular is Tequilla, which is made from a single species, Agave tequiliana.

Now, Sotol alcohol has joined the ranks of the “hot new spirits”. Made from agave’s cousin, plants of the genus Dasylirion, Sotol is rapidly becoming the new “flavor of the month”. Sotol alcohol certainly isn’t new, and if you regularly travel south of “the wall” you probably already know that Sotol is the state drink of Mexican states Chihuahua, Coahuila, and Durango.

Not so long ago, Sotol alcohol had a history that somewhat parallels moonshine in the Southeast US. For years, Sotol alcohol was illegal and subject to government raids, during which master sotoleros were punished or imprisoned. During the US prohibition of the 1920s, Sotol sales in the US skyrocketed, but soon after its repeal, Sotol sales plummeted back into obscurity. Now, with not only social acceptance, but a wide wide embrace of virtually anything that can be used to produce alcohol, Sotol has been mainstreamed with the assistance of the Mexican government and willing marketers.

Most agaves for Tequila production are now commercially grown in massive farms, and most plants are now produced from tissue culture for a more consistent yield and to take pressure off wild popuations. Even under ideal farming conditions, it take 5-7 years to get an agave large enough to harvest for tequilla production. With dasylirions, the same process takes at least 12-15 years according to Sotol marketers. Based on our 30 years of work with the genus, I’d say the time involved is more likely 24-30 years, even in a high rainfall climate like ours.

I’m not aware of many farm operations that can afford to grow a plant for that long before expecting a return on investment. This means that poaching of plants from the wild is very likely to increase. With such a low rate of return, i.e. 1 pint of liquor for each plant harvested, I can’t see the plants coming out on the good end of this industry. While making alcohol from dasylirions isn’t new, it’s been done on a very limited scale in Mexico, prior to word spreading around the world via social media.

Reportedly Sotol spirits taste quite different based on the species used, and whether it’s from an exceptionally dry region or an area with better rainfall. Sotol conniseurs describe the tastes as being a bit like menthol or pine/mushrooms if the plants are grown well hydrated, while those from drier regions taste more like leather. To quote Dave Barry, “I’m not making this up!” And this sounds appealing to who???

Supposedly, the spirit producers are cutting off the wild dasylirions and leaving the bases to resprout, but I’ve got my doubts about how well that works. Assuming the cut dasylirion does resprout, there will be a decade of lost seed production, so plant populations in the wild are almost certain to decline. I’m left to wonder if we really are so desperate for a new taste in alcohol that we are willing to sacrifice another genus of plants in the process.

In celebration of these amazing plants, here are photos of those we have grown in our ex-situ conservation gardens at JLBG.

Dasylirion acrotrichum, named in 1843, is native to Mexico’s Chihuahuan desert. Of the seven plants we planted, only one survived, which is now over 20 years old. This widespread sotol, which occurs on igneous soils, has been split by various authors into several subspecies. Undoubtedly, winter hardiness varies based on the seed procurement location. At maturity, the trunks can reach 5′ tall.

Image of Dasylirion acrotrichum
Dasylirion acrotrichum

Dasylirion berlandieri, named after French/Mexican naturalist, Jean-Louis Berlandier (1803-1851), was first published in 1879. Native to steep rocky hillsides in Tamaulipas and Nuevo Leon in Northeastern Mexico, it’s one of the largest species in the genus in width, but with a trunk that never exceeds 1′ in height. Below is our plant in bud. Unlike agaves, dasylirion rosettes do not die after flowering.

Dasylirion berlandieri

Below is a fully open flower spike, which is abuzz with a large number of bees

Dasylirion berlandieri in full flower

Dasylirion cedrosanum, first documented in 1911, hails from 3,000′ – 6,000′ elevation on rocky, gypsum-laced hillsides in the Sierra Madre Occidental mountain range. They are restricted to the Mexican states of Chihuhua, Coahuilla, and Durango. At maturity, they produce a 3′ tall trunk.

Dasylirion cedrosanum

Dasylirion durangensis is another species first described in 1911, which hails from the dry alkaline/limestone-gypsum deserts of Coahuila, Chihuahua, Durango, and Zacatecas. In parts of its range, it interbreeds with Dasylirion wheeleri. We flowered this prior to losing it during a particularly cold winter. Below is our Obit photo.

Dasylirion durangensis

Dasylirion gentry was only published as a species in 1998. It has a very limited range between 3,500′ – 4,000′ in Sonora, Mexico, where it grows on rocky slopes in openings of pine/oak woodlands.

Dasylirion gentryi

The inflorescense of Dasylirion gentryi is one of the most spectacular we’ve ever seen.

Dasylirion gentryi bloom spike

Dasylirion glaucophyllum is a species whose discovery dates back to 1858. It can be found naturally, only in Sonora, Mexico, growing on rocky hillsides at elevations to almost 8,000′. At maturity, trunks measure up to 6′ in height.

Dasylirion glaucophyllum

Dasylirion leiophyllum, published in 1911, only grows north of Mexican border in Texas and New Mexico. Based on where it grows, it should be one of the most winter hardy sotol species. The first photo is at JLBG, and the second in situ at 5,400′ elevation. The second image is from the late plantsman, David Salman, of a Zone 5 population he discovered and shared seed with us just prior to his untimely death. Plant Delights is currently offering this as Dasylirion leiophyllum ‘Chaves’.

Dasylirion leiophyllum – in winter at JLBG
Dasylirion leiophyllum ‘Chaves’ in situ at 5,400′ elevation

Dasylirion miquihuanense, only described in 1998, hails from Tamaulipas and Nuevo Leon in Northeastern Mexico. Also occurring on rocky slopes, this sotol is one of the tallest species, producing massive 8′ tall trunks. We have succeeded long term with only 2 of 8 specimens we planted.

Dasylirion miquihuanense

Dasylirion parryanum, published in that banner year of 1911, hails from up to 8,000′ elevation in the San Luis Potosi State in Northern Mexico, where it produces 3′ tall trunks.

Dasylirion parryanum

Dasylirion quadrangulatum (1879) hails from the Southern (warmer) end of Tamaulipas and Nuevo Leon. It is much too tender for us to grow in the open here in Zone 7b, but we’ve kept it alive for a couple of decades by siting it in a microclimate adjacent to a brick wall house foundation. It is one of only two species lacking leaf spines. With great age, it produces trunks to 9′ in height.

Dasylirion quadrangulatum

Dasylirion serratifolium, first described in 1838, is from Oaxaca, Mexico, where is grows on rocky, alkaline hillsides to 6,600′ elevation. The location and elevation means it really shouldn’t survive our winter. That said, our only remaining specimen below is now 20 years old, but is still far from reaching the 6′ tall trunk height it does in the wild.

Dasylirion serratifolium

Dasylirion texanum (1850) is another very winter hardy species, found on rocky slopes, ranging from Central Texas into the mountains of Northern Mexico. It is one of the shortest species, with a trunk that doesn’t exceed 1′ tall.

Dasylirion texanum

Dasylirion wheeleri, first documented in 1878, ranges from Texas, Arizona, and New Mexico south into the mountains of Northern Mexico. It matures at 6′ tall, and in situ, can be found in both grasslands as well as openings in pine/oak forests. It is another of the most cold hardy species.

Dasylirion wheeleri

An old clump we planted years ago in flower is quite remarkable.

Dasylirion wheeleri in flower

We hope you’ll limit your consumption of Sotol as a drink and instead join us in becoming an ex-situ conservation garden for this amazing genus of plants.

Supersize Me

In 2014, we decided our goal for the years’ century plant breeding project was to see how large a Zone 7b winter hardy agave we could create. We had seven agaves flower that year, but only two had the epic proportions we required.

One of those was a selection of Agave x protamericana from a Yucca Do collection in Northern Mexico. By the time of flowering at 15 years of age, it had reached 5′ tall x 9′ wide.

Agave x protamericana and Agave americana are the two largest blue-foliaged agaves, but only Agave x protamericana is winter hardy for us, here in Zone 7b, since it also has some ancient genes from the hardier Agave asperrima, which adds slightly to its winter hardiness. You can distinguish the two plants by feeling the back of the leaves. Agave americana has smooth leaf backs, while Agave x protamericana has sandpapery leaf backs. The largest size listed for Agave americana in Howard Gentry’s Agaves of Continental North America, is 6′ tall x 12′ wide.

A large growing agave with blue green foliage growing in our zone 7b garden.
Agave x protamericana YD45-79

At the same time we had a blind flower shoot on our giant Agave x pseudoferox ‘Bellville’. Agave x pseudoferox is another ancient Mexican hybrid in need of a DNA workup. We think it’s probably a hybrid of Agave x protamericana with Agave salmiana var. ferox and possibly Agave gentryi). Commercially, it’s usually called Agave salmiana var. ferox, which is similar in appearance, but with absolutely no winter hardiness.

Prior to full flowering at 15 years of age, our giant specimen of Agave x pseudoferox ‘Bellville’ had reached a mature size of 4′ tall x 8′ wide. We were able to make the cross prior to it fully flowering, by using something we mentioned above that we call “blind shoots” or boners.

Being monocarpic plants, the rosettes of most agave species die after flowering, but side shoots are an interesting phenomenon we see on all of our Agave x pseudoferox cultivars and hybrids. These “blind shoots” emerge from underground stolons instead of from a rosette. They are much shorter than normal flowering shoots which emerge from the rosettes (2′ tall vs. 20′ tall), and they have no impact on the life expectancy of any of the rosettes.

In the case of Agave ‘Bellville’, our plant began producing blind shoots five years prior to the clump producing a full size, rosette-based flower stalk. The beauty of blind shoots is that they breed and pass along characteristics of the parent without the need for a tall ladder.

Agave 'Bellville' is another large blue green form that produced "blind shoots" which are flowering shoots produced from the underground stolons.
Agave x pseudoferox ‘Bellville’

We gave our hybrids the seed strain cultivar name, Agave ‘Bluebell Giants’. From these, we selected 23 clones, which were planted in the trial fields in 2016. Of those, only 4 survived our subsequent trials for winter hardiness.

Our seed crop of the hybrid from the two large growing blue green agaves.
Agave ‘Bluebell Giants’

Our best and most winter hardy seedling from the cross pictured below is now 6 years old in the garden. We’ve given this the name Agave ‘Supersize’. It has achieved a size of 6′ tall x 8′ wide in that time. To put this in perspective, it is larger at 6 years old than both parents were at 15 years old. If Agave ‘Supersize’ waits until age 15 to flower, it could easily reach more massive proportions that any Zone 7b winter hardy agave in existence.

A clonal selection from the hybrid seedlings, A. 'Bluebell Giants' that has passed our hardiness trials.
Agave x pseudofox ‘Supersize’

Glorious Gloriosa

Our 2008 introduction of a selection of our native Yucca x gloriosa ‘Lone Star’ has been absolutely splendid in the garden as the fall season begins. Yucca x gloriosa is a natural hybrid of Yucca aloifolia and Yucca filamentosa. We absolutely love that these flower spikes appear at a time when most other plants are past their seasonal prime. Winter hardiness is Zone 7a-9b.

Yucca x gloriosa Lone Star in bloom
Yucca x gloriosa ‘Lone Star’

Yucc’ing it up

We’ve been playing around with yucca breeding for almost a decade, and now have hybrids that include from 3-5 different species. Here’s a shot of one of our evaluation beds when it was in full flower recently. Flower spike height ranged from 3′ to 10′. There should be some wild and crazy introductions once our trials are finished.

Image of Yucca in full flower at the JLBG evaluation beds
Yucca in full flower at the JLBG evaluation beds

Stingray in the Garden

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.

Agave bracteosa Stingray in the garden
Agave bracteosa ‘Stingray’ in the garden

Shadow Dancer

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.

Agave x romanii 'Shadow Dancer' potted on the deck
Agave x romanii ‘Shadow Dancer’

Bearing Flowers

Our tallest clump of Nelson’s bear grass has been in full flower for the last month, making a spectacular site. Our specimen, which has reached 10′ in height is now 23 years old from seed. This woody lily which hails from the state of Tamaulipas in Northern Mexico forms a yucca-like stalk in the garden. All of the other hardy bear grasses have green foliage, so the blue foliage of Nolina nelsonii is quite distinct. The common name of bear grass was coined on the Lewis and Clarke expedition, when nolinas were mistaken for yuccas, which at the time were known as bear grass. Hardiness is Zone 7b-10b.

Nolina nelsonii

The Look of Love

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.

Agave ovatifolia ‘Vanzie’
Agave x ovatispina ‘Blue Arrows’
Agave lophantha JLBG-01
Agave x loferox JLBG-014
Agave x pseudoferox JLBG-176

Snowgaves

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.

Agave x amourifolia
Agave x loferox

Washington’s Palm ready for winter

Due to having three consecutive mild winters, with no temperatures below 20 degrees F, we’ve actually been able to get a trunk on our Washingtonia filifera palm. Typically not hardy in our climate, our plant was grown from seed collected from a wild population in Arizona that had experienced 10 degrees F. We’ll see what this winter has in store.

Sex for the Centuries

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.

Agave x amourifolia

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.

Agave x ovox ‘Large Ox’

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.

Agave x protifolia

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.

Agave x ovatispina ‘Blue Arrows’

Below is Agave x ocareginae, our 2016 cross of Agave ovatifolia x Agave victoriae-reginae. Most likely, this elegant small grower will never offset.

Agave x ocareginae

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.

Agave x schuphantha ‘Wheel of Fortune’

Gentle Yucca

Most folks think of yuccas as only sharp plants, but one that’s sharp without being sharp is our Southeast US native Yucca x recurvifolia…a naturally occurring hybrid between Yucca aloifolia and Yucca flaccida. Here is the clone Yucca x recurvifolia ‘Variegata’ in the gardens this week. Hardiness is Zone 6b/7a and south.

Mad About xMangave!

The genus xmangave is an exotic botanical curiosity that was derived from a cross between a succulent¬†agave and a manfreda. Crosses between two genera are somewhat rare in cultivation and extremely rare in nature. However, agave and manfreda have broken all the rules and ‘hooked up’ on more than one occasion to produce the attractive offspring called x Mangave. The ‘x’ on the left side of Mangave tells you that it is a cross between different genera.

xMangave ‘Blue Mammoth’

Both parents contribute drought-tolerance and an aversion to winter moisture. Keep your x Mangave roots dry in winter to prevent rot. We like them in containers. We have been busy making new x Mangave hybrids…so check back for updates!¬†

xMangave also make great container specimen.