Hey Bartender…Give me Another Shot of Winter

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 bracteosa ‘Stingray’ is the most winter hardy of all brightly variegated agaves we’ve tried. Here is our plant looking quite lovely after our 11 F cold.

Agave bracteosa ‘Stingray’

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.

Agave weberi ‘Stone Cold Austin’

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.

Agave lechuguilla ‘Tater Tot’

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.

Mangave ‘Racing Stripes’

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.

Bambusa multiplex ‘Green Giant’ – north side undamaged

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.

Bambusa multiplex ‘Green Giant’ – south side, sun scorch damage

We didn’t hold out much hope for the Mexican palm, Brahea decumbens, but it sailed through 11F unscathed.

Brahea decumbens

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.

Chamaerops humilis var. microcarpa with foliar damage
Chamaerops humilis var. microcarpa undamaged

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.

Sabal palmetto ‘Bald Head Island’

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.

Cycas x panzhioluta

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.

Viburnum ‘Moonlit Lace’

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.

Opuntia microdasys ‘Dripping Springs’

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.

Sedum praealtum

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.

Lithops, living stones, are much more winter hardy than reported. The key is keeping them dry, planted under an overhang in our crevice garden.
Lithops aucampiae

Delavayi’s Schefflera

We love the winter hardy Chinese schefflera, Schefflera delavayi. This smaller and hardier version of the small tree that’s planted throughout central and southern Florida, is reliable for us here in Zone 7b. Here’s an image taken just prior to our first hard freeze. It’s been a few years since we got viable seed, so fingers crossed for this year.

Schefflera delavayi in flower at JLBG
Schefflera delavayi in flower

Flaming Torch

In flower this week is the amazing ginger lily, Hedychium ‘Flaming Torch’…our 1999 introduction, with its’ fragrant peachy flowers is still looking great! This is another of those plants that never sold particularly well, so we haven’t offered it since 2016. Winter hardiness is Zone 7b and warmer.

Hedychium Flaming Torch in the garden
Hedychium ‘Flaming Torch’
Close up of Hedychium Flaming Torch
Hedychium ‘Flaming Torch’

Hear, Hear…lend me an ear

We always look forward to elephant ear evaluation day at JLBG, which was recently completed.

The colocasia trial gardens at Juniper Level
Colocasia trials

Each year, Colocasia breeder, Dr. John Cho flies in from Hawaii to study and select from our field trials of his new hybrids. This year we were joined by Robert Bett, owner of the California-based plant marketing firm, PlantHaven, who handles the Royal Hawaiian elephant ear program. The JLBG trials consist of all named colocasia introductions growing alongside Dr. Cho’s new hybrids created the year prior.

Robert Bett (l), John Cho (r) beginning the colocasia evaluation.
Robert Bett (l), John Cho (r)

JLBG staff members, Jeremy Schmidt and Zac Hill spent most of the morning working with Robert and John on the time-consuming evaluation process.

Robert Bett (l), Zac Hill (c), John Cho (c), Jeremy Schmidt (r) evaluating elephant ear plants
Robert Bett (l), Zac Hill (c), John Cho (c), Jeremy Schmidt (r)

After lunch, Jim Putnam from Proven Winners, joined us to see which remaining plants struck his fancy for potential introduction into their branded program. As you can see, lots of amazing plants didn’t make the final cut, which is necessary, since we’ll need more room for the new selections.

John Cho, Robert Bett, Jim Putnam inspecting the colocasia selections
John Cho, Robert Bett, Jim Putnam

Plants selected for introduction are then sent to a tissue culture lab to be produced for the next step, which is grower/retailer trials. If these are successful, and the plant can be multiplied well in the lab, the plants are scheduled for retail introduction.

Hopefully, by now, most folks are familiar with our 2020 top selection, Colocasia ‘Waikiki’, which hit the market this year. There are more really exciting new selections in the pipeline, but we can’t share photos of those quite yet…stay tuned.

 Colocasia 'Waikiki', our top 2020 colocasia selection
Colocasia ‘Waikiki’

Deceived Ginger

The amazing Hedychium deceptum from India, has recently burst into flower here at JLBG. This species is fairly new to commerce, but has proven to be an amazing, compact-growing specimen that thrives even in our full sun. The dark cinnamon calyces really make the scarlet flowers stand out. We rate this as hardy to Zone 8a, but that’s because we simply don’t have enough data yet, but we’ll be very surprised if it’s not fine in Zone 7b.

Hedychium deceptum in flower at JLBG
Hedychium deceptum in flower at JLBG
Close up of Hedychium deceptum - Red Hardy Ginger Lily
Close up of Hedychium deceptum

Goin’ Bananas

We’re always on the search for new bananas that will be winter hardy without protection in our Zone 7b winters, and two that have looked great so far are the South Asian native Musa balbisiana (Northeast India to South China) and the Northeast Indian native Musa nagensium var. hongii. If these continue to thrive, we will propagate these so we can share.

Musa balbisiana - one of the banana plants being trialed at JLBG/PDN
Musa balbisiana
Musa nagensium var. hongii - one of the banana plants being trialed at JLBG/PDN
Musa nagensium var. hongii

Amazing Angolans

Gardeners in Zone 7b wouldn’t typically think of Angola (tropical West Central Africa) as a place to search for hardy perennials, but we’ve been thrilled with the performance of two natives of the region, Crinum fimbriatulum and Crinum jagus. The reason we kill so many plants is we try things that people with better sense would assume wouldn’t have a chance of the proverbial snowball.

Crinum fimbriatulum is flowering now for us, while Crinum jagus bloomed a few weeks earlier. Crinum fimbriatulum is the taller of the two, with spikes reaching nearly 4′ tall. Our plants were planted in 2009. They thrive in average to above average soil moisture.

Image of Crinum fimbriatulum in bloom
Crinum fimbriatulum

Crinum jagus has been in the ground at JLBG since 2015. It’s a much shorter plant with 2′ tall flower spikes, but with incredibly lush, attractive foliage.

Image of Crinum jagus 'Mayan Moon' flowering
Crinum jagus ‘Mayan Moon’

A Time for Turmeric

I’m always amazed that so many people don’t realize that turmeric (Curcuma longa) is an amazing garden perennial. We’ve had our plants in the garden for nearly 30 years. This week, the flowers of this delightful ginger lily from Southern India emerge, looking like fancy pink pine cones. Curcuma longa is very easy to grow, as long as the soil is reasonably well-drained. Just mark the planting spot, since it usually doesn’t break ground before June. Hardiness is Zone 7b-10.

Image of Curcuma longa ( Tumeric ) flowering
Curcuma longa
Close up Image of Curcuma longa ( Tumeric )flowering
Curcuma longa flower

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.

Cycad-o-Rama

We are just loving our hardy hybrid cycads in the garden this time of year, and here are two we photographed this week. The first is Cycas x bifungensis (bifida x taitungensis), and the second is Cycas x panziholuta (panzhihuanensis x revoluta). We have found that hybrids between hardy species are even more winter hardy than the species themselves. Hardiness for both is probably Zone 7b and south.

Cycas x bifungensis
Cycas x panziholuta

Sunrise over Maui

Here’s a recent image of the amazing Colocasia esculenta ‘Maui Sunrise’, still looking great in late October! Moist, rich soils and full sun are the key for your plants to look this spectacular! Winter hardiness is Zone 7b and warmer.

Colocasia esculenta ‘Maui Sunrise’

It ain’t worth a thing if it ain’t got that bling!

Apologies for commandeering the famed Duke Ellington line, but it seems appropriate for the new Colocasia ‘Waikiki’.

Colocasia esculenta ‘Waikiki’

When we first met Hawaii’s John Cho in 2003, we knew some special elephant ears would be the result of our collaboration, but it was hard to imagine something like the seriously tricked-out Colocasia ‘Waikiki’. Almost every year, John, who has now retired, but is still actively breeding elephant ears, travels to JLBG to evaluate his new hybrids at our in-ground trials and make future introduction decisions. There are some seriously amazing new selections starting down the introduction pipeline.

Colocasia trials
Colocasia ‘Waikiki’
Colocasia ‘Wakiki’

Colocasia ‘Waikiki’ will be released from Plant Delights Nursery on January 1, so if you like this, mark you calendars and stay tuned to the website.

Can you say Poo-yuh?

As an avid bromeliad collector back in the 1970s, I’ve had a long fascination with members of the bromeliad family. Although, I’m long past my house plant days, I continue to test bromeliads from cold climates for their adaptability in our Zone 7b NC garden. So far, we’ve had one member of the genus Puya to survive for well over a decade, so we’re trying more. Here is our trial clump of Puya caerulea var. violacea this week, where it is thriving so far in the crevice garden. This 2.5 year old plant is just waiting for a really cold winter to see how it fares, but so far, so good.

Flaming Torch of Summer

The 7′ tall, and very floriferous Hedychium ‘Flaming Torch’ is looking quite stunning today in the garden. Although they are commonly called ginger lily, they are not a true lily (genus Lilium) or a true ginger plant (genus Zingiber). Hedychiums are prized for their summer and early fall floral shows atop bold-foliaged stalks. The inflorescences are quite exotic looking, resembling clusters of orchids. Slightly moist, rich garden soils and at least 1/2 day sun are best for these hardy tropical looking plants.

Elliptical Ginger Lily

Here’s another oddity in the fabulous ginger genus, hedychium. First, Hedychium ellipticum requires shade, compared to most hedychiums that need sun to flower. Also, Hedychium ellipticum has pendant stalks, compared to the rigidly upright stalks of most more commonly grown ginger lilies. We love the elegant flower heads that adorn the garden in late July/early August. This photo is from the gardens at JLBG last week. Hardiness is Zone 7b south. Sadly, this is always a poor seller when offered by Plant Delights…perhaps people just need to see this in person to appreciate its exquisite beauty.

Four long weeks!

Last year, we were thrilled when one of our cycads produced a female cone…a first for JLBG. We subsequently impregnated it with pollen supplied from the garden of one or our former volunteers, Mike Papay. Our plant produced a great seed crop (56 seed), which was recently planted.

As a point of reference, I should mention that cycads are dioecious…each plant is either male or female. The genus cycas is one of the oldest known surviving plant genera, having emerged between 250 and 350 million years ago, when it diverged from ginkgos. Cycas, having been around for a very long time, also have supercharged, swimming sperm…a trait not seen in modern plants.

This year, we welcomed our first male cycad to cone. The first photo was taken 1 month prior to the second photo, so it’s taken that long for this males’ cone to grow from a tiny bulge to be ready to spread its pollen (sperm). Since we don’t have any flowering females in the garden this year, we’re shipping off the pollen to a palm and cycad breeder in Georgia. This afternoon, we used the Lorena Bobbitt technique to sever its cone, which is now boxed (bottom image) and leaving town before the plant rights groups find out.

Canna show you this?

Flowering at our exit drive this week is the beautiful Canna ‘Red Futurity’…a superb purple-foliaged canna lily. Learn more about growing canna lilies in your garden.

Meet Hamabo

We expect most everyone has grown a hibiscus at one time or another, either tropical or hardy. How many of you have tried the Asian Hibiscus hamabo? This fascinating 8-10′ tall evergreen shrub has thrived in our trials since 2018, and is just now flowering at JLBG for the first time. We had always considered this species tropical, so we were thrilled to hear that it survived as a die back at the SFASU Arboretum in Texas after this springs’ arctic blast of -4F. Dr. Dave Creech at SFASU tells me that it remains evergreen down to 10 degrees F. Has anyone else had experience with growing this outdoors in a cold winter climate?

Hidden no longer

Late June is when the amazing hidden cone gingers (curcuma) begin to explode here at JLBG. Here is our clump of Curcuma ‘Pink Wonder’ this week emerging from what looked like a bare patch of ground in the woodland garden. After the flowers finish, the red-striped foliage explodes to 6-7′ tall.

Gardening Unplugged

It’s hard to believe that it is already time for our 2019 Fall Open Nursery & Garden Days! My how time flies.

During each day of our Open Nursery & Garden Days, we offer a free garden chat as part of our educational outreach, Gardening Unplugged”. These are 15 minute discussions walking through the gardens, focusing on seasonally prominent topics, plants and garden design ideas. Join Tony and our expert horticultural staff as we explore all that nature has to offer. Meet at the Welcome Tent near the parking lot to join us!

This Fall topics include:

Dividing perennials – Crinum being dug to divide
Hardy Tropicals
Scent-sational Ginger Lilies
Fall Blooming Bulbs – Crinum buphanoides

Smellivision

When will they develop scratch and sniff smart phones?

“I’ll never forget my first encounter as a preteen with Hedychium coronarium, when my dad took me to the garden of a local gardener, Rachel Dunham. There, in the midst of her lawn was a huge clump of hardy ginger plant in full flower. I was amazed how a plant that looked so tropical and had such fragrant flowers could be so winter hardy and easy to grow. Since Mrs. Dunham was overly generous, I went home with a huge sack of plants for my own garden. As with every OCD gardener, this would mark only the beginning of my hedychium collecting phase, which continues today. Thirty five years later, I would finally see ginger lilies in the wild on a botanical expedition to North Vietnam.” Tony Avent

Join Tony, Saturday September 21 at 10:00am, during our 2019 Fall Open Nursery & Garden Days as he talks about the scent-sational ginger lilies at Juniper Level Botanic Garden.

Hedychium ‘Vanilla Ice’

Retirement Garden Party

Each year we offer nearly 1,500 unique, rare and native perennials for sale, out of the 26,000 taxa in the garden.

xAmarcrinum ‘Dorothy Hannibal’

As we are constantly trialing new plants coming to the market and evaluating underutilized or unknown perennials from around the world, we must retire hundreds of plants each year to make room in our greenhouses for new treasures. Here are a few of our favorite plants being retired at the end of this year, so don’t miss out!