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.

Genetics Matter

We have long been enamored by the elegant, evergreen fern, Polystichum neolobatum, but have failed countless times with the commonly sold material in the horticultural trade. It was not until we grew spores from a Hans Hansen Chinese collection from 7,000′ elevation in China’s Sichuan province that we met with success. Below is a specimen from that trip, taken here at JLBG last week.

As is the case with so many commercially sold plants, their origin is lost. While the commercial material of Polystichum neolobatum may be fine in the cool temperatures of the Pacific Northwest, that is simply not the case here in the hot, humid Southeastern US. This species has a wide native range from the Himalayas all the way to Taiwan, where it can be found from 4,000′ elevation to 10,000′ elevation. Both elevation and origin location matter when determining the adaptability of many plants. We are finally getting good spore set, and hope to be able to make this form available through Plant Delights in the near future.

Polystichum neolobatum ‘YuWa’

Falling for Ginkgos

Gardeners typically curse fall leaf drop, but ginkgo trees often get a pass, not only because the golden fall leaves look so great on the tree, but they also look great on the ground, not displaying the disheveled look of other larger tree leaves. Here’s our ginkgo tree, planted just in front of our office, that’s been putting on quite a show for the last few weeks.

Ginkgo trees are know for their brilliant golden yellow fall color.
Ginkgo biloba

Despite what most folks think, the genus Ginkgo is indeed a North American native, but to understand that, requires a bandwidth that many native plant purists simply don’t have. Native is not a place in location, it is only a place in time. The first Ginkgos date back to the lower Jurassic period about 190 million years ago, when the genus was born in Mongolia. From there, it migrated around the world, based on dramatic climate change, with fossils found from what is now the UK to the US (Oregon to North Dakota).

Ginkgos continued to diversify through the Cretaceous period (65-145 million years ago), when they reached their maximum distribution, with 5-6 species currently recognized. By the Paleocene (56-66 million years ago), all of the species but one had gone extinct. Although that remaining species is known as Ginkgo adiantoides, it is almost identical to today’s Ginkgo biloba.

During the Oligocene (23-34 million years ago), Ginkgos moved south from their more northerly range, with the genus completely disappearing from North America around 7 million years ago. According to the fossil records, Ginkgos subsequently disappeared from Europe around 2.5 million years ago. The only vestiges of the genus that remained, holed up in three distinct refugia (botanical hideouts) in China until humans began to spread them out again and re-populate the rest of the now Ginkgo-less world. They returned to the Flora of both North America and Europe in the 1700s.

For those who want to dive deeper into the Ginkgo story, here is a link and another.

When Ginkgo trees are ready to shed their leaves, they normally do so within a day.
Ginkgo biloba

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

Asparagus kissin’ cousin

Ok…raise your hand if you’ve grown Aphyllanthes monspeliensis? This odd, monotypic (only member of the genus) is actually a member of the Asparagus family. Hailing from France south into Northern Africa, Aphyllanthes can be found growing in hot, dry, sandy soils, where it produces an amazing spring show of blue flowers on a 1′ tall clumper. The species name “monspeliensis” is named after Montpellier, France, where it grows naturally. Our plants are thriving in our crevice garden, putting on a superb flower show in mid-April.

Purple leggings

Iris ‘Gerald Darby’ is one of those iris that doesn’t even need to flower to be garden worthy. Here it is in our garden this week, emerging with its’ purple leggings. This gem is a North American native hybrid of Iris versicolor and Iris virginica, known as Iris x robusta. This introduction of Iris breeder Gerald Darby was actually named for him after his death by another iris breeder R.H. Coe of England. Iris x robusta ‘Gerald Darby’ is equally at home growing in standing water as it is in typical garden soil. Hardiness is Zone 4a-9b.

A Little White Lying Groundcover

False lily-of-the-valley (Speirantha gardenii) is one of our favorite early spring-flowering evergreen groundcovers for shade, but one that just hasn’t caught on with customers. Every time we put this back in production at Plant Delights, we wind up throwing out most of the crop. Perhaps one day, folks will realize what a gem this is. Hardiness is Zone 5b-8b.

Super Food Perennial

Will someone please explain to me why more people aren’t growing the amazing sea kale, Crambe maritima. This amazing perennial is a great tasting green that returns every year without replanting. It’s also a great flowering perennial, putting on a show now in our rock garden. We have also never seen any pest activity such as typically bothers other members of the cabbage family. Our plant is growing in half-day sun in pure gravel (in our crevice garden), and never receives any supplement irrigation. The economic return from Crambe maritima is huge. I guess some folks may not find it attractive, but darn, folks!

Atamasca or Atamasco?

Ever since I was a small kid, I’ve observed Zephyranthes atamasco (atamasco lily) in the wild, where they grow in swampy wooded lowlands. Atamasco lily is also one of many great nomenclatural muddles with regard to it’s correct spelling. When it was first named by Linneaus, back in 1753, it was assigned to genus amaryllis, so the specific epithet was spelled “atamasca”.

In his later work, Linneaus changed the spelling to “atamasco”, which corresponded to the Native American name for the bulb. It remained spelled with an “o” even after it was moved into the genus Zephyranthes in 1821. The problem is that, according to International Nomenclatural rules, the original spelling must take precedent. So, Zephyranthes atamasca is correct. Except…there is an exemption for name conservation, when correcting the name will cause confusion or economic harm. There is currently a well-supported move underfoot to conserve the long-used spelling “atamasco”. And you thought nomenclature was boring!

I’ve long marveled at the diversity within the species, and as an adult have been fortunate to be able to collect offset bulbs from some of the special forms I’ve found.

The top image is a very compact form that we’ve named Zephyranthes ”Milk Goblet’. Below that is one of our larger flowered forms from Alabama that we named Zephyranthes ‘Hugo’. Hugo has 5″ wide flowers in a species where 2.5-3″ wide is typical. Both of these are in full flower now at JLBG.

Zephyranthes atamasco ‘Hugo’

Flowers at Flower Hill

We’re just back from a quick outing to the Flower Hill Nature Preserve in Johnston County, NC…just a few miles from JLBG. This unique coastal plain site contains remnants of species more common in the NC mountains, nearly 5 hours west. The top of the bluff is a small stand of enormous Rhododendron catawbiense, while along the bottom of the hill is a bank of the deciduous Rhododendron canescens.

Rhododendron catawbiense
Rhododendron canescens

In the mid-slope area, we found Cypripedium acaule (pink ladyslipper orchid), just waiting to be photographed. Sadly, it’s one of the most difficult species to transplant, so just enjoy these in situ when you find them.

Cypripedium acaule

There were beautiful masses of the evergreen groundcover galax, growing on the eastern slope.

Galax urceolata

It was particularly great to see the Asarum vriginicum in full flower. True Asarum virginicum is rarely seen in cultivation, and the diversity of flower color was outstanding.

Asarum virginicum
Asarum virginicum
Asarum virginicum
Asarum virginicum

NC State/JLBG Day of Giving

Wednesday, March 23, 2022 is the NC State University Day of Giving…a time for those who want to support activities at NC State. In our case, that means the endowment we are building to preserve Juniper Level Botanic Gardens. If you care about ensuring the gardens remain intact for future generations, please consider making a contribution to the endowment. You can do so at this link to the University Endowment Fund for JLBG.

For those who are relatively new to the gardens, here is a link to a historical timeline of the JLBG garden development.

You can find out more about the mission and future of the gardens here