Below are three of our final selections of Agave x ovox, which we made out of several hundred seedlings. These are each sister seedlings from our cross of Agave ovatifolia x Agave pseudoferox ‘Bellville’ It’s always interesting to see how many different ways the genes sort out. These are from our 2018 cross, and only went in the ground in 2021, so despite their size, they’re still babies at 2′ tall x 4′ wide. So far, they are showing some true hybrid vigor. Each should mature around 4-5′ tall x 8-12′ wide. These are all fine in Zone 7b and south.
Below is a variegated sport of M. ‘Mission to Mars’. These have reached 5′ in width.
Mangave ‘Foxy Lady’ is a variegated sport of M. ‘Silver Fox’
Plant breeding is a wonderful hobby that attracts an array of hobbyists, as well a plant professionals. Many plants, such as hemerocallis, hosta, hibiscus, and iris, are so easy that they attract the majority of hobbyist breeders. Professionals and the craziest of the breeders occasionally focus on more difficult plants that few others are willing to try. This includes plants where the pollen exchange is complicated either by timing, incompatibility, or other constraints. Such is the case with century plants (agave).
Peak flowering season for 2023 is drawing to a close at JLBG, while one new agave is just in mid-spike. We only had 13 different agaves flower this year, compared to 18 last year. Fortunately, we are able to save and store pollen in the refrigerator, where it will remain viable for at least 5 years.
Below are a few images of Steve Guptill of our garden staff, as he made crosses last week. At the bottom of the first image is our volunteer agave specialist, Vince Schneider, who is training Steve to make the crosses.
With agaves, the process involves waiting for the stigma to become sticky–a sign that it’s receptive to the pollen. Pollen is then gathered from our prospective father and then hauled up the 21′ ladder to the waiting stigmas. Not only are you high in the air, but you’re working around hundreds of bees that are busy gathering copious amounts of nectar.
Assuming we get seed set, they should be ripe by late September/early October.
Both spiking agaves in the photo below are our selected hybrids from previous years breeding.
It’s fascinating to see how many amphibians in the garden are drawn to agave leaves. We find more amphibians resting on agaves than any other plant in the garden. Here is our latest image capture of our native green tree frog, Hyla cinerea.
We were thrilled how well Agave x protamericana ‘Silver Surfer’ came through the 11 degree F. cold snap this winter. This 2007 Plant Delights/JLBG agave introduction was our selection from a Yucca Do Nursery seed collection in Northern Mexico of a naturally occurring hybrid between Agave americana and Agave asperrima.
Agave x protamericana ‘Funky Toes’ is looking fabulous in the garden today, having sailed through our cold winter in tip top shape. This unique form of the well-known North American native agave is an introduction of the former Yucca Do Nursery, from one of their collections in Northern Mexico.
In 2018, we found a streaked leaf on a potted offset. By using a technique called crown cutting, we were able to isolate the bud from the streaked leaf into a yellow center, which we named Agave ‘Funky Monkey’…photo below. Hopefully in the next few years, we’ll have enough of this new introduction to share.
Agave ‘Crazy Horse’ is an amazing agave hybrid we purchased back in 2005 from an Ebay seller in Texas. The vendor had found the plant growing at a real estate office in Montgomery County, Texas. It’s obviously a hybrid, but we still don’t know the parentage for sure. If we had to guess, it appears to be a hybrid of Agave x protamericana and Agave cupreata. In the 18 years, we’ve grown it, it’s been an exceptional plant, forming 3.5′ tall x 5′ wide rosettes, and suckering tightly against the main clump. This year, it sailed though our winter cold of 11F. It’s been almost a decade since we’ve offered this, so perhaps it’s time we propagate a few more to share.
In 2011, we spotted a tiny creamy white streak on a single leaf of a small pup, which was potted for further observation. After several years, and thanks to crown cutting, we were able to produce a highly-streaked plant, which we call Agave ‘Craziness’…see below.
Several years later, we were able to isolate the streaked leaves into a stabilized central variegation we named Agave ‘Bareback Rider’. Although winter hardiness also disappears with the creamy white foliage, it still makes a superb container plant. With that much white in the leaf, the growth rate has also slowed dramatically. It’s our hope that within the next year or two, we can finally release this amazing form through Plant Delights.
I had to chuckle as folks on several Facebook plant groups were wringing their hands in worry prior to the recent cold snap, while we were secretly hoping for even colder temperatures than forecast.
JLBG registered three consecutive nights in the teens recently; 11F, 19F, and 19F. While this was certainly not abnormal for our area, folks with very short memories thought the horticultural world was coming to an end. In reality, we recorded similar temperatures in the winter of 2017/2018, albeit a week later that year.
When we first started the gardens at JLBG, we were squarely on the Zone 7b side of the Zone 7a line. We are now on the Zone 7b side of the Zone 8a line. In order words, we have shifted about 1/4 of a hardiness zone. Since 2018, JLBG has registered three consecutive Zone 9a winters, so it’s not surprising the new gardeners or those with short memories start assuming that all kind of plants are reliably winter hardy, which is not the case.
We long for cold temperatures because we want and need good winter hardiness data, and while mild winters may be enjoyable to us Homo sapiens, we don’t learn anything about plant hardiness from those winters. So, here are a few things we learned this year.
Agave weberi ‘Stone Cold Austin’ is Patrick McMillan’s collection of Agave weberi from Austin, Texas. We’ve tried Agave weberi a couple of times prior, and could never get it through one of our milder winters. Patrick’s original plant at Clemson got large enough to flower there, so we’re hoping for the same. The older foliage is showing damage from 11F, and will most likely be lost, but the bud seems fine so far.
We’ve never had any luck with any of the dwarf Agave lechuguilla mutants we’ve tried in the garden, but this new one, shared by plantsman Hans Hansen, that we call Agave ‘Tater Tot’, had no problem with 11F. These are often sold as Agave x pumila, which actually doesn’t exist. Everyone assumed that A. x pumila was a hybrid, but when one in Europe recently mutated back to the original form, it turned out to be nothing more that a super dwarf form of Agave lechugullla.
Mangave ‘Racing Stripes’ is a plant we had high hopes for in terms of winter hardiness, but we had not had a cold enough winter to get good data. Our only reservation was that it contains genes from the tropical Agave gypsophila. Thankfully, our plant came through the 11F freeze in reasonably good shape. The wrinkled nature of the older leaves are indications of cold damage that will show up in a few more days, but the core seems intact and should re-grow.
We fully expected Bambusa multiplex ‘Green Giant’ to be defoliated after 11F and the stalks killed to the ground, but our fully exposed clump still looks like it’s mid-summer…at least from the north side.
On the south side, the same clump has fried foliage. There are typically two causes for such damage. One is wind desication when the winds are blowing from a single direction and the ground is frozen, making it impossible for the plant to replenish water lost through the foliage. During the time that our ground was frozen, our winds were coming from the West, so that wouldn’t account for damage only on the south side of the plant.
In this case, the more likely scenario is that this is due to sun scorch when the soils was frozen, since the damage is on the south side. If the canes are indeed undamaged, as it appears, new leaves should reflush in spring.
We didn’t hold out much hope for the Mexican palm, Brahea decumbens, but it sailed through 11F unscathed.
Since we know that genetics matters, we will often plant more than one clone of a marginal plant like a new palm. Below are two seedlings of the small-seeded European Fan Palm, Chamaerops humilis var. microcarpa. The first shows significant foliage burn, while the second plant, growing nearby shows no damage after 11F.
The hardiest of all Sabal palmetto forms are those from NC’s Bald Head Island. Our plant from there came through the cold unscathed. We expect many local businesses and even homeowners who purchase large trunked forms directly from Florida growers will probably be in for a disappointing spring.
All of our hardy cycads have assumed the straw-color we see every year when the temperatures drop below 18 degrees F. The plants are fine, but we recommend waiting to remove the dead fronds, since doing so now, can cause the new foliage to emerge in the middle of winter, which is never a good idea. April 1 is our target date to remove the fried foliage.
One of the real surprises was the fried foliage of Viburnum ‘Moonlit Lace’, where it was growing in full sun. The same plant growing in shade looks untouched. The stems are fine and the plant should re-sprout fine, but gardeners who grow this in full sun may be disappointed.
This is the coldest temperatures we’ve seen since planting Patrick’s hardy selection, Opuntia microdasys ‘Dripping Springs’. Our clump looks great after the cold. It’s hard to imagine that this clone is so much more winter hardy than any of the other forms of this species that we’ve tried previously and killed at much warmer temperatures. Although we don’t offer this for sales, I’ll remind you of our great prickly pear cactus giveaway at our Summer Open Nursery and Garden in July.
The Mexican Sedum praeltum looks a bit sad, but actually seems to be fine with sound buds up and down the stem. This little-known perennial forms a plant that looks almost exactly like the tender Jade plant, Crassula ovata.
Lastly, our patches of Living Stones, Lithops aucampiae, sailed through 11 degrees F. I wonder if we can ever get all the disinformation on the Internet regarding their tolerance to cold corrected.
Our oldest clump of the North American native Agave lophantha ‘Splendida’ is preparing to celebrate its 10th anniversary in the garden at JLBG. What started as a single pup, now has an extended family. Please join us in sending birthday wishes to this great century plant selection.
Looking great in the garden this week is Agave x pseudoferox ‘Green Goblet’. This 1996 introduction from the former Yucca Do Nursery is one they found in Mexico and brought back as a single pup. Our original plant flowered in 2011 after 11 years in the ground, so this specimen has re-grown from one of the remaining small pups. Since we’re now at 11 years since last flowering, we’re preparing for a new blessed event. Since we can usually tell by now if it’s expecting, which it is not, the odds are pretty good for a 2024 flowering. Plant Delights Nursery will be offering A. ‘Green Goblet’ for sale in 2023.
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.
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.
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 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.
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.
Below is a photo of both parents.
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
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.
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.