Planting more Needles

Every year when we have a significantly cold winter, we are reminded of the wonder of the Southeastern native needle palm, Rhapidophyllum hystrix. This native of Northern Florida and nearby areas in the adjacent states of South Carolina, Georgia, and Alabama, is the most winter hardy palm in existence.

Established needle palm clumps have been documented to have survived -15 F to -20F. I still remember checking on the old specimen at the JC Raulston Arboretum in Raleigh after we dropped below 0F for two consecutive nights in January 1985 (-3 on Jan 20, and -9 on Jan 21). I was amazed I was to find the plant undamaged by the cold. Below is one of our many specimens in the garden after our 11 F freeze a few weeks ago.

Needle palm is generally considered to be a non-trunking palm, although with great age, it will develop a short trunk, that will eventually become decumbent. I’m fascinated why this and other native palms are never promoted by the native plant enthusiasts.

Image of Rhapidophyllum hystrix
Rhapidophyllum hystrix

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

Origin of the Bayou Babes

One of our favorite palms for the garden is the US native Sabal minor var. louisiana. While it can’t outgrow the Himalayan Trachycarpus fortunei (windmill palm) for speed of developing a trunk, Louisiana palmetto is the most winter hardy of all trunking palms. One of the mysteries is that in the wild, the same population can have both above ground as well as subterranean trunks.

Our garden specimen in the photo below was planted from a 1 qt. pot in 2005. Eventually, Sabal minor var. louisiana will develop an above ground trunk, which on our specimen below is just beginning.

The background on Sabal minor var. louisiana is a botanical mystery. Some taxonomists consider it a valid species, while others consider it variety of the subterranean trunked Sabal minor. Others consider it to be an old hybrid of Sabal minor and either Sabal mexicana or Sabal palmetto. A similar hybrid, Sabal x brazoriensis from near Dallas, had its DNA analyzed several years ago, and was found to be an old hybrid of Sabal minor and a now extinct population of Sabal palmetto.

Sabal sp. ‘Tamaulipas’ from Northern Mexico is another mystery palm in need of some family history work. Thankfully, palm researcher and grad student, Ayress Grinage at Cornell has begun to look at these mystery sabal palms to figure out how they came to be. We, and others have sent material, and now await the results of the paternity test.

Sabal minor var. louisiana in the garden
Sabal minor var. louisiana

Decumbent Brahea

Considered the hardiest of the genus Brahea, this rare endemic palm hails from the alkaline Sierra Madre Oriental Mountains in northeastern Mexico, where it’s endangered thanks to the abundance of hungry goats.

Brahea decumbens is ridiculously slow growing. Eventually, the immature green leaves turn a beautiful silvery grey and adorn the 6′ tall x 10′ wide specimen that, with age, develops creeping (decumbent) trunks…much like a blue-leaf Serenoa repens.

We’ve failed three times, loosing each in the winter. Zac mentioned that these need an extremely abusive and neglected environment to survive, so we planted our fourth attempt in our gravel crevice garden where it receives no irrigation. After 3.5 years, it’s actually thriving and looking particularly nice this fall.

Brahea decumbens in the crevice garden
Brahea decumbens

Low Country Treasure Hunt

Last week, Patrick, Zac, and I spent a couple of day botanizing in the low country…i.e. Coastal South Carolina. In between swatting away the incredible troupe of mosquitos which chose to join us, we were able to capture a few images to share below.

The ancient lime sinks are fascinating. Here, old sinkholes due to subsurface limestone rock breakdown have collapsed, forming natural depressions, creating a habitat for our native pond cypress (Taxodium ascendens) and other fascinating wetland species…like alligators. Yes, we did see several, but they were too fast for our camera.

Taxodium ascendens, our native pond cypress
Taxodium ascendens
High water marks visible on Taxodium ascendens
Taxodium ascendens

The high water marks are visible on the buttressed trunks of bald cypress.

Close up of high water marks on Taxodium ascendens
Taxodium ascendens

Much of the region is, or was, a pine/grass habitat. The pines could either be longleaf (Pinus palustris) or slash pine (Pinus serotina) .The dominant grass is known as wiregrass, aka: Aristida beyrechiana.

Wiregrass habitat
Pine/Wiregrass habitat

On the dry sand ridges, we saw these piles of fresh sand adjacent to a nearby tunnel entrance. These are homes to the rare gopher tortoise, which live in the region. Patrick tells me these tortoises will use the same underground lair, which may stretch 40′ long and 10′ deep, for up to 60 years.

Gopher tortoise tunnel
Gopher tortoise mound/tunnel

Gopher tortoises only emerge from their tunnels when temperatures are between 80 and 90 degree F. Sure enough, we were able to wait and get some images of these amazing creatures.

Close up of a Gopher tortise
Gopher tortoise

Another surprise spotting was a bright orange mutant katydid. Our entomologist Bill Reynolds tells me these are crazy rare, and worth well north of $1000 to collectors. Who knew?

 Close up of Orange katydid
Orange katydid

Yes, we also saw some cool plants. Asclepias obovata is a little-known milkweed that’s quite rare in South Carolina, so it was great to catch it in flower.

Asclepias obovata, a little known milkweed
Asclepias obovata

At another site nearby, we caught some late flowering plants of Asclepias tuberosa var. rolfsii.

Asclepias tuberosa var. rolfsii
Asclepias tuberosa var. rolfsii

We visited several patches of amazing pitcher plants, one site with a tremendous variation of Sarracenia flava, which is typically solid yellow. Other sties had three species growing side by side including Sarracenia minor, Sarracenia rubra, and Sarracenia flava. It’s great that such natural area still exist, although they are always in danger from those who sadly dig plants from the wild for sale.

Sarracenia flava in situ
Sarracenia flava in situ
Sarracenia flava clump - typical yellow pitchers
Sarracenia flava clump – typical yellow pitchers
Sarracenia flava red pitcher form
Sarracenia flava red pitcher form
 Sarracenia flava red pitcher form
Sarracenia flava red pitcher form
 Close up of Sarracenia flava red pitcher form
Sarracenia flava red pitcher form
Sarracenia flava with a particularly large hood
Sarracenia flava with a particularly large hood
Sarracneia flava with brown hood and nice veining
Sarracneia flava with brown hood and nice veining
Sarracenia flava red neck form
Sarracenia flava red neck form
Sarracenia minor
Sarracenia minor
Sarracenia rubra
Sarracenia rubra

A plant often seen near the pitcher plants is the native orchid, Plantanthera ciliaris.

Plantanthera ciliaris orchid
Plantanthera ciliaris orchid

We were thrilled to find a couple of large patches of the scrub palm, Serenoa repens, from one of the coldest natural populations, which happened to be in full seed. Clonal patches like this are incredibly slow-growing. Researchers in Florida found that such clonal patches are often between 5,000 and 10,000 years old.

Serenoa repens clonal patch
Serenoa repens clonal patch
Serenoa repens clonal patch
Serenoa repens clonal patch
Serenoa repens seed
Serenoa repens seed

It was great to see large drifts of one of our finest native ferns, Thelypteris kunthii, aka: maiden fern. This superb deciduous fern thrives in both sun and shade, tolerating everything from wet to average soil conditions.

Thelypteris kunthii
Thelypteris kunthii

A lovely surprise was stumbling on a population of Hamamelis henryi. This coastal species is often listed as a variety of Hamamelis virginiana, but we think it’s probably deserving of species status. Several of the clones we found had lovely dusty blue foliage.

Hamamelis henryi
Hamamelis henryi

One of the most amazing shrubs was the hawthorn, Crategus munda var. pexa. These ancient specimens topped out at 4-5′ tall, and looked like ancient bonsai specimens.

Crategus munda var. pexa
Crategus munda var. pexa

I’ve long had a penchant for finding gold leaf sweet gums, and this trip added another one to the list. When many woody plants are cut to the ground, they are much more likely to produce mutations as they re-sprout. In my experience, the genus Liquidambar must be the most prone to such mutations.

Liquidambar styraciflua gold sport
Liquidambar styraciflua gold sport

The fall-flowering Georgia savory, Clinopodium georgianum was in full flower. We’ve grown and offered this for decades, but it was fascinating to see the flower color variation in the wild.

Clinopodium georgianum
Clinopodium georgianum

At one stop, we found five different liatris species, including the little-known Liatris elegans.

Liatris elegans
Liatris elegans

The native vining legume, Centrosema virginiana, aka: butterfly pea, was in full flower and looking lovely…first cousin to the better known genus, Clitoria.

Centrosema virginiana
Centrosema virginiana

I’m not a fan of most smilax species, but I was quite smitten by the non-running dwarf Smilax pumila, which grew in the shade like an Asarum (wild ginger). While some clones had green leaves, others had patterns every bit as good as the best Asarum.

Smilax pumila
Smilax pumila

On the ride home, we kept ourselves amused unscientifically researching the fastest speed at which leaf-footed bugs could hold onto a car window while copulating. Since our test speed topped out at 65mph, we aren’t sure what it was take to pry these loose, but perhaps someone should research how they are able to hold on so tight, as I’m sure it has numerous industrial applications.

Leaf-footed bug leaving the Low Country with us
Leaf-footed bugs

Bald Head, but Sexually Active

If you’ve lived in the deep south…the land of palmetto palm trees, you know that they typically don’t flower until they have at least 5 feet of trunk. Of course, flowering can be sped up by a combination of precocious genes and good growing conditions. Those who have studied Sabal palmetto in the wild have noted that the earliest populations to flower are those from the most northern, naturally-occurring population on North Carolina’s Bald Head Island.

Well, sure enough, our oldest specimen of Sabal palmetto ‘Bald Head’, planted in 1999 finally decided to produce flower this summer, and will hopefully seed. We’ve only had enough plants of this cold hardy form to offer through Plant Delights three times in 36 years. Fingers crossed, we’ll be able to make it available more regularly now. Hardiness Zone 7b and warmer.

Sabal palmetto 'Bald Head'
Sabal palmetto ‘Bald Head’

Struck Gold

Here’s a garden shot at JLBG, using a good bit of gold foliage in addition to flowers. Left to right: Viburnum dentatum ‘Golden Arrow’, Sinningia ‘Amethyst Tears’, Baptisia ‘White Gold’, Canna ‘Tama Tulipa’, Lysimachia nummularia ‘Aurea’ (groundcover), Hibiscus ‘Holy Grail’ (purple), Spirea thunbergii ‘Ogon’, Trachycarpus fortunei (palms).

Are you a blue fan?

We love our Mediterranean blue fan palms…one of the coolest palms we can grow outdoors. We’re right on the edge of winter hardiness for Chamaerops humilis var. argentea, so the key is to grow it to a larger size before planting in the ground. We’ve lost a few that we planted too small, and when that planting coincided with a cold winter.

This is a photo taken this January of our oldest clump, now 17 years old. This is a very slow growing palm, so a good bit of patience is required when getting it established. When we do experience single digits F winter temperatures, all of the foliage is burned back, but it re-sprouts from the base in spring. Mediterranean blue fan palm hails from high elevations in the Atlas Mountains of Morocco, where it eventually makes a 15′ tall specimen. In our cold winter climate, we doubt it will ever top 4′ in height. It should be winter hardy from Zone 7b and warmer.

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.

Blackburn’s Palm

We love plant mysteries, and Sabal ‘Blackburniana’ fits the bill nicely. This pass-along seed strain has been considered by some to be an old hybrid of Sabal minor, while others consider it to be synonymous with Sabal palmetto, yet others consider it to be Sabal domingensis. Whatever it is, our plant is looking quite good in the garden. After growing it, unscathed, since 2008, we finally decided to propagate some for the upcoming Plant Delights catalog. If you know any more historical background about this curiosity, please share.

Are you a blue fan?

No, we’re not talking about your favorite football or basketball team, but the amazing blue Mediterranean fan palm. Here’s our oldest (16 year) specimen in our alpine rock garden this week. Chamaerops humilis is a Southern Europe native that’s marginally hardy in our region, but the blue form, know as var. cerifera (or var. argentea). is much more tolerant of our cold winters. If our winter temperatures drop into the single digits F, the foliage dies back to the ground, but quickly rebounds in spring.

Chamaerops humilis var. cerifera

Cold Hardy Palms of the Carolinas

Did you know that North Carolina has twice as many native palms as California?

Join garden volunteer, Mike Papay, on a virtual tour of Juniper Level Botanic Garden as he discusses native and cold hardy palms of the Carolinas as part of our Gardening Unplugged garden chat series, held each day of our Open Nursery & Garden Days.

Windmill Palm – Trachycarpus

EverGreenery!

Evergreen trees and shrubs are the perfect way to spruce up your home during the holiday season. They will hold up for weeks in arrangements and wreaths, anywhere you need a touch of holiday cheer.

Here are some inspirations from the garden. Explore your holiday creativity.

Finished arrangement made from four branches and a bow – palm frond, magnolia, variegated osmanthus and Virginia red cedar.

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

Hardy Palms for Your Garden

We are continually on the hunt for new cold hardy palms. When we find an individual clone of hardy palm tree growing in a particularly cold climate, we do what all good plant nurseries do, we propagate it for our plant catalog! There is no reason why gardeners in Tennessee or Virginia cannot have a cold hardy palm tree in their yard just like a Floridian.

Sabal palm

Try pairing hardy palms with other tropical looking plants like colocasia, musa, and hedychium. Join Zac Hill, our taxonomist, July 20 at 2 PM as he discusses hardy palms in the garden. This is part of our free garden chat series, Gardening Unplugged, during each Open Nursery & Garden Days.

Windmill palm
Needle palm