Here’s our clump of Chrysopsis gossypina in the garden this week, looking shockingly like a South African Helichrysum petiolare (straw flower). This little-known Southeast US native (Virginia to Mississippi) is usually found on dry, sandy soils. So far, our plants of the short-lived cottony golden aster are thriving in our well-drained agave/cactus berms. The yellow daisy flowers should be appearing soon.
Okay, raise your hand if you grow Orbexilum lupinellus in your garden? I’m still looking for hands out there… This endemic to longleaf pine/wiregrass habitats in the Coastal plain from NC south to Alabama, is a delightful rock garden plant, that’s made itself right at home at JLBG, flowering beautifully in late August/early September. This is growing in a rarely irrigated rocky section and has thrived in both the heat and drought. It’s probably not showy enough to offer commercially, but we sure enjoy it.
Raise your hand if you’ve grown the Southeast native perennial, piriqueta. Piriqueta caroliniana is a little-known Southeast US native that hails from NC, south to Florida. Botanically, it’s a member of the Turneraceae family, after being unceremoniously booted from its previous home in the passiflora family, Passifloraceae. We had never heard of the genus before Patrick introduced us a couple of years ago.
So far, our plant is thriving in our dry alpine garden, where it shares a bed with agaves and other desert denizens. For us, flowering begins in mid-summer, although in more southern climates, it reportedly flowers almost year round. For us, the flower open around lunchtime, and close by 5pm. We’re still testing its winter hardiness, but it sailed through this winter’s 11 degrees F, with no problems.
We’ve been fortunate to grow a huge number of hardy garden ferns through the years, but it’s hard for any to top the amazing Pleopeltis lepidopteris, to which, we’ve given the common name, Brazilian hairy sword fern.
Below is a patch at JLBG, composed of three individual clumps, looking great, despite the ravages of summer. This sun-loving lithophytic (rock grower) also grows fine in well-drained soils. In habitat, it hails from the sandy, acidic coastal (restinga) habitats in southern Brazil (Rio Grande du Sul). Our plants came from our friends at the former Yucca Do Nursery, who made a beach front collection in Brazil in 2012. It doesn’t appear that fern had been in cultivation prior to that time.
The 18″ tall x 2″ wide, rigidly upright fronds emerge covered in thick silver hair, to which I can now relate. As the fronds age, the hair thins and the green leaf surface becomes more visible. Pleopeltis lepidopteris spreads slowly from surface rhizomes. We’ve grown this evergreen Pleopeltis in our rock garden since 2012, where it has thrived even through winter temperatures of 7 degrees F. Hardiness Zone: 7b to 9b, at least.
I can’t remember when I first met Cylindropuntia kleiniae, but it was somewhere back in my early years, during a family cross country drive, designed to expose us kids to the entirety of the US. I fell in love with cactus, despite being repeatedly stabbed as I tried to rescue a pad to take home.
Since that time, I’ve encountered this native of Texas, New Mexico, and into Mexico more times than I care to remember. This hardy pencil cactus is the Charlie Brown’s Christmas tree of cacti…kinda homely, but loveable in a motherly sort of way. In the garden, it forms an open 6′ specimen.
July has been a great month to enjoy the floral show of the most winter hardy member of the genus Aloe. Our plant of Aloe cooperi, below, is happy as can be, growing in half day sun in our crevice garden.
Back in the 1970s, when I was specializing in house plants, one of my favorites was the epiphytic fern genus, Aglamorpha. These staghorn relatives made delightful hanging baskets, despite being far outside the bell curve in regards to recognizability to most gardeners.
Over the years, as I migrated more to hardy perennials, I gave up most of my house plants, but not before trying most of them in the ground. As you can imagine, aglmorphas were a failure, but I never gave up on the idea of finding a winter hardy one.
Fast forward some 40+ years later, I spotted an aglamorpha-like fern in the crowded cold frame at England’s Pan Global Plants. Examining the tag, which read, Drynaria sinica, led me down another rabbit hole, where I discovered that the genus Aglamorpha and Drynaria had recently been joined due to a botanical merger.
In the new group of 30+ species, one, Drynaria sinica, came from an elevation of over 12,000’…a certain sign of potential hardiness. My purchase made it through both the inspection and shipping process, and now thrives in our rock garden, where it sailed though 11 degrees F this winter. Despite a recent name change to Drynaria baronii, we are very excited about this hardy epiphytic fern, and look forward to eventually having some to share.
We have been playing around with the genus Polygonella since 2000, but have still only grown 3 of the 11 US species so far. We are fascinated why these native, highly drought-tolerant members of the buckwheat (Polygonaceae) family aren’t more widely grown.
The common name of jointweed, probably is the biggest factor in their lack of popularity, but then botanist aren’t usually known for their marketing prowess. The plants do have joints, but they are far from being weeds. Polygonellas look like miniature subshrubs of obscure green joints until they burst into flower with hundreds of tufts of small white flowers, that are covered by all kinds of bees.
Below is a current photo of our 4-year-old clump of Polygonella americana. In my humble opinion, honeybee keepers should be planting these everywhere, since they flower during what is known as the “nectar dearth” season, starting here in June. For us, Polygonella americana flowers from June until October. Our plant is growing the un-irrigated crevice garden in a Permatill dominant soil, since great drainage is essential.
Globularia is a genus of small, rock garden-sized plants in the Plantaginaceae family, with a native distribution centered around Mediterranean Europe. I admired these during our 2012 Balkan expedition, but it wasn’t until we constructed our crevice garden empire, that we really began to have much success with the dryland plants in our wet, humid summer climate.
We’ve now tried 15 of the 22 known globularia species, and have only lost two of those outright. While globularias are usually grown for their puffy blue, ball-shaped flowers in spring, we love species like Globularia repens for its habit as a slow-growing, dense groundcover. The key to our success is a soil mix of 50% Permatill, which is a lava-like popped slate. Hardiness Zone 4b-8a.
For those who regularly attend our Open Nursery and Garden days, you have no doubt watched the evolution of our new dryland rock garden by our welcome tent. I thought it would be fun to look back at its short evolution. Below is Jeremy’s bed outline from late January 2021, when this new bed was only a vision in our heads.
In late January 2021, Jeremy broke ground by digging down until we reached undisturbed subsoil, which was then loosened.
The next step was to add our planting mix, which consists of 25% native soil, 25% compost, and 50% Permatill (a popped slate gravel). The planting media was thoroughly mixed with the subsoil, which ensures continuous drainage by not layering different soil types. The final height of our bed was 5.5′, with the knowledge that we would loose about 6″ in final height to settling. Planting began in early March 2021.
Below is the same area taken this week–27 months after construction. The bed is 35′ long with an average width of 15′, which would give us 525 square feet of bed space–if the bed was flat. With our finished height of 5′, we actually have close to 800 square feet of planting space–50% more surface area, all because we raised the bed height.
Because these are dryland plants, this section of the garden is un-irrigated, except during extended periods of severe drought and above normal heat. We hope this “peaks” your interest in both the science and art of rock gardening. If so, the North American Rock Garden Society (NARGS.org) is an amazing group of like-minded folks with an incredible seed list of treasures for this type of garden.
Here’s another of those plants that virtually no one has either grown or even knows about. Handelia trichophylla is a little-known monotypic member of the aster family (Asteraceae). Not only does it have hairy, silver foliage, which usually spells certain death in our summers, but it hails from the “stans”, which include the low rainfall countries of Afghanistan, Kazakhstan, Kirgizstan, Pakistan, Tadzhikistan, Turkmenistan, Uzbekistan, and Xinjiang. Our particular plant is from a seed collection in Tadzhikistan.
We would not typically expect anything native to the “stans” to survive in the hot, humid Southeastern US, but this is why we experiment, and why we create unique habitats and microclimates in our garden. In this case, Handelia has thrived for four years in our crevice garden, where it grows in a soil mix of 50% Permatill.
This winter took out several of our trial barrel cactus, but despite the losses, we’ve still got a good selection of survivors. Peak flowering season is late April through late May, so below are a few that we’ve manage to photograph during that period. The key for growing barrel cactus in cold wet climates is excellent winter drainage and bright sun. There are many genera to choose from, as you’ll see below.
Coryphantha scheeri is a Chihuahuan desert species that ranges from Texas south into Northern Mexico.
Coryphantha macromeris ssp. runyonii is a sea level species that’s only found on both sides of the Rio Grande River, which divides the United States and Mexico.
Echinocereus coccineus is native to much of the Southwestern US. This seed grown collection hails from Hudspeth County, TX.
Echinocereus x roetteri is one of our favorites. This naturally occurring hybrid between Echinocereus coccineus and Echinocereus dasyacanthus has flower colors that range through the entire rainbow spectrum. This is a stunning purple flowered form, we grew from seed from Pecos. County, TX.
Echinocereus palmeri is another Chihuan Desert species from Northern Mexico.
Echinocereus papillosus var. angusticeps stradles the Texas/Mexico line. Our plants sailed through our 11F winter.
This beautiful clump of Echinocereus reichenbachii var. baileyi was grown from seed from a population in Granite, Oklahoma.
Gymnocalycium deeszianum hails from south of the Equator in the Cordoba Province of Argentina. Unlike most of the previous cactus, which tolerate or prefer alkaline soils, gymnocalycium prefer acidic soils.
Notocactus floricomis is another superb performer from Argentina
Notocactus x hertonis is from a Mike Papay cross of the pink flowering Notocactus herteri and the yellow-flowering Notocactus ottonis.
Finally, Notocactus x subteri is another superb Mike Papay hybrid of the pink-flowering Notocactus herteri and the yellow-flowered Notocactus submamulosus.
In the hot, humid south, the word Dianthus is jokingly translated as “prepare to die”. As of this spring, we’ve grown 169 different dianthus taxa (different accessions). Of those, most are dead, a few are hanging on, and then a much smaller subset are absolutely thriving. Below are a few images from the spring garden of some (but not all) which are thriving spectacularly.
The first image is Dianthus anatolicus, planted in 2020. Virtually unknown by most gardeners, this species is native from the Black Sea region into the West Himalayas. Typically, plants from this region don’t thrive in our heat and humidity, so this was a pleasant surprise. This is growing in our typical compost amended garden loam.
Dianthus arenarius is a Baltic Sea species that has thrived for us since 2018 in our crevice garden.
Dianthus Dianthus kuschakewiczii, aka: D.tianshanicus, a Central Asian native, has also fared amazingly well in our compost ammended beds since 2015. The idea that this tolerates our heat and humidity is quite shocking.
Dianthus plumarius is a well-known garden species, originating from the Northwest Balkan peninsula. It has been grown as a pass-along perennial throughout the Southeastern US for over a century. This species has been cultivated in the UK since 1100AD, and in the US since 1676. Our clone is one that has been passed along in the Birmingham, Alabama area.
The horticultural world has been replete with an array of dianthus hybrids through the years. We’ve managed to kill quite a few, but the ones below have been exceptional in our tough conditions. Dianthus ‘Bright Light’ (aka: Dianthus Uribest52), is a Korean hybrid from the breeding firm, Uriseed, which was derived from crossing Dianthus alpinus (from the Alps) with Dianthus callizones from Romania. Our clumps have been in since 2018, and excelled in unirrigated sections of the garden. This is one of the finest garden dianthus we’ve ever grown.
Dianthus ‘Cherry Charm’ is a Dutch hybrid of Dianthus gratiopolitanus , which has been every bit as exceptional as Dianthus ‘Bright Light’. Our clumps, which are now four years old are nothing short of outstanding.
Dianthus ‘White Crown’ is the smallest of the excellent performing selections in our trial. We have had this in the crevice garden since 2017, growing in 3′ of Permatill, so we doubt this would thrive in typical garden soils. This is a Wrightman Gardens introduction of unknown parentage.
Looking lovely this spring has been our patch of Marshall’s Barbara’s Buttons, Marshallia caespitosa. This cute perennial hails from prairies from Missouri south to Texas and will be available this fall. Hardiness is Zone 5a-8b.
Looking lovely now at JLBG are two species of Texas blue bonnets; Lupinus subcarnosus (top) and Lupinus texensis ‘Abbott PInk’ (bottom). Both are winter annual species that dot the Texas highways in spring. These are on of a very short list of annuals that we allow in the garden.
These have returned for us for 20 years. The key is to plant the seed in a dry area, especially one that is mixed with Permatill. The seed germinates in late fall, and the plants flower the following spring.
Since we opened the Souto sun garden section of JLBG to the public, circa 2014, we’ve been dealing, rather poorly, with an unsightly water runoff capture pit on the east side of the garden. The 30′ x 30′ pit was first filled with weeds, and later converted to a bed for marginal aquatics like cannas and crinums. Over the last few years, cattails had taken over, rendering it somewhat more attractive, but far less diverse.
Three years ago, we made the decision to transform it into a styillized bog garden/rock garden combination. To do so, would require the elimination of the cat tails, which took the better part of two years. Last year, with the cat tails finally eliminated, Patrick, Jeremy, and I strategized what we wanted the bog to look like and how we would make it happen. Armed with everyones’ input, Jeremy took over the construction design and implementation.
Our first step was to remove several truckloads of squishy muck that covered the bottom, since this would not provide the stability we needed to set large rocks.
With the pit finally firm and level, it was time to closely examine water flow from both surface and subsurface water.
Next, the pit was re-filled with our native sandy loam, with a central “gravel burrito”, which would allow subsurface water a way to exit without erupting upward into the planting area.
The next step was the installation of underlayment and the pond liner. Despite the site being already waterlogged due to a high water table in the area, we felt that the use of a liner would give us more precise control over the water level.
To keep the liner from floating while we worked, we began refilling the bog with our new soil mix of 50% native sandy loam and 50% peat moss. Around the edges, where the rock garden would be installed, we used a base of concrete blocks to support the weight of the rocks. These were located on the outside of the liner, so the blocks would not leach chemicals into the acidic, nutrient deficient bog.
In the center of the bog, we used double-wall drain pipe, stood on end to support the centerpiece of huge boulders.
The large rock feature was then installed on top of the support pipes, along with an ancient stump which Jeremy unearthed on the property.
Rocks with planting pockets were then installed along the edge on top of the cinder block wall. .
The final step was the installation of entrance steps into the bog and pathway stones, which will allow visitor a closeup view of the plants. Initial plants are in the ground, but more will be added as they are ready. The crevices planting mix (same as the bog) has a pH of around 4.0, compared to all our other crevice gardens on the property, which have a pH around 8.0. This should allow us to grow an entirely new array of plants.
From start to finish, the entire project took Jeremy, Nathan, and some occasional help from other staff, 3 1/2 weeks…job well done!
We hope you’ll drop by during our spring open house and check out the new Rock Bog in person.
A couple of years ago, we were thrilled to acquire seed of Euphorbia ‘Rubicund’ from the Hardy Plant Society seed exchange. That little-known clone is a selection from a cross of Euphorbia myrsinites x E. rigida made by Rhode Island’s Issima Nursery. While the clone doesn’t come true from seed, we love our offspring and look forward to seeing what our seed crop from the plant below will have in store.
For this hybrid, we’ve settled on the nothospecific name E. x myrsida, going forward. Over 15 years ago, we acquired a similar cross from California salvia guru, Betsy Clebsch, but we unfortunately let our plant get shaded out. Both plants we’ve grown of this cross produced much larger seed heads with a form similar to both parents. It has been stunning in our our rock garden for the last month. Hardiness is probably Zone 6a-8b.
We love the late winter flowering Drabas, which thrive in our dry crevice garden. Below is the miniature Draba hispanica, which has been in flower since late February. This Spanish species likes to grow in dry limestone cracks, such as the one we provided here. Unless you’re an avid rock gardener, you may not realize that draba is actually in the cabbage family, Brassicaceae. Once the flowers finish, you’re left with a fuzzy evergreen bun of foliage for the rest of the season. Zone 5a-8a, at least.
Flowering for the last week in the garden is the lovely winter iris, Iris reticulata ‘Painted Lady’. Iris reticulata is unusual in that it has bulbs instead of rhizomes. In the wild, it calls home the dry regions from Turkey to Iran. These spring ephemeral iris go to sleep for the year by late spring/early summer. Hardiness is Zone 5a-8b, at least.
I’m betting that even the most seasoned plant collectors probably haven’t grown or even heard of Urophysa henryi. This odd generic member of the Ranunculaceae family hails from China, where it can be found only in a very few scattered populations, hanging out from cliff-side karst rock fissures in Guizhou, Sichuan, Western Hubei and into Northwestern Hunan.
Urophysa henryi is very closely related to the highly prized, but rather difficult to grow, rock garden plant, Semiquilegia adoxoides. I was particularly interested to read in a 2021 Chinese research paper, “In field observations and laboratory experiments, we found that U. rockii and U. henryi can not survive outside the karst limestone, which indicated that the karst limestone plays a significant role in their growth and development.” This is why you never send a botanist to do a horticulturist’s job!
In our garden, sans the Karst limestone, it has thrived in our rock garden, not blinking this year at 11F. The 4″ tall x 6″ wide evergreen clumps of columbine-like foliage are topped with clusters of small, outfacing white flowers, which resemble our native Isopyrum biternatum, Like Isopyrum, Urophysa flowering starts for us in early January, and continues through March. We think these are an outstanding addition to the winter garden and are going to do our best to get these propagated to share before words gets out that they can’t be grown in cultivation.
11 degrees F was a bit more than our clump of Massonia depressa had hoped for. Although the cold temperatures burned a bit of one leaf, it not only survived, but is now in full flower. That’s pretty amazing for a South African bulb that Wikipedia authoritatively states “does not tolerate freezing temperatures”. Rock on!
We were thrilled to see most of our plants of Trichocereus ‘Love Child’ come through the 11 degrees F unscathed. We hope to have enough of these in the next year or two to share. We had long wanted to grow and offer some of the ridiculously large flowered, tacky colored tropical trichocereus cactus, but they simply had no winter hardiness.
Enter our former volunteer curator, Mike Papay, who had the same idea, but was more determined to make it happen. Mike worked with Trichocereus bruchii, and the resulting second generation plants yielded one he named Trichocereus ‘Big Time’.
He created another winter hardy hybrid using Trichocereus bruchii and Trichocereus thelogonus that he named Trichocereus ‘Iridescent Watermelon’. We subsequently crossed both of Mike’s hybrids together to create a seed strain we named Trichocereus ‘Love Child’. Below is one of our garden plants after enduring 11 degrees F. Below that is the same plant in flower last spring. Hardiness zone 7b to 10b.
I’ve posted about daphnes a couple of times this year, but can’t help post again now that we’re in December and still have two daphnes in full flower, despite two nights at 25 degrees F.
The top is Daphne collina from Southern Italy, and the bottom is Daphne x napolitana ‘Bramdream’…a hybrid of Daphne collina x Daphne cneorum var. pygmaea. These are growing in our dry crevice garden in a soil mix of 50% Permatill gravel. It seems obvious that the Daphne collina is the source of the continuous bloom. Winter hardiness is Zone 6a-8b (top), and Zone 5-8b (bottom).
One of my most lustful plants has been the super cute Euphorbia clavarioides var. truncata. I first ran into this fascinating poinsettia cousin at the Denver Botanic Gardens in the 1990s, and have subsequently killed it 5 times, prior to the construction of our crevice garden. Now, our specimen below is 2.5 years old and thriving. The key is perfect drainage and no water in the winter.
Below is a giant clump, which we saw in the wilds of South Africa in 2005. These massive clumps are considered to be well over a century in age, so our little patch has a lot of growing to do.
Raise your hand if you grow the native October Flower? Polygonella polygama is a little-known, but absolutely amazing wildflower in the Buckwheat family, suited to well-drained, sunny gardens. Although completely non-descript through spring and summer, when people are buying plants, it bursts into flower in October, also when no one is buying plants. Below is our plant strutting it stuff in one of our full sun rock gardens in mid October. Polygonella polygama is native from Virginia southwest to Texas, along the coast. Winter hardiness should be at least Zone 7b and south.
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.
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.
You go straight through to the round of botanical superstars if you recognize this little-known southeast native (SC to Florida), Piriqueta caroliniana. This Patrick McMillan collection from coastal SC has thrived all summer in our full sun rock garden, flowering constantly, with new flowers opening every other day. This oddity is a member of the Turneraceae family, which comprises nine other equally obscure genera. We’ve yet to determine if this will actually make a good garden plant, but evaluation continues. Hardiness north of Zone 8a is unknown.
One of the stars of our late summer/early fall garden has been our selection of Chrysopsis mariana ‘Little Miss Sunshine’. We made this roadside collection of this East Coast native in 2020 in neighboring Orange County, NC, unsure of what we had collected, but loving the purple stems of this clone. This planting in our rock garden has produced an amazing 18″ tall x 2′ wide specimen that glows for months. Dry soils and at least half day sun are the keys to success. We’ll start propagating this showy, clumping native perennial in spring. Winter hardiness is Zone 4-8.
Looking lovely in the garden today is the fall-flowering geophyte, Sternbergia sicula. This Mediterranean native is found in the wild growing on alkaline hilly sites. Some taxonomists list it as a subspecies of the more common Sternbergia lutea, but it seems consistently smaller. At JLBG, our plant thrives in the crevice garden. Hardiness is Zone 6a-8b.
Our planting of Glandulicactus wrightii is looking quite lovely as we head into fall. Sadly, few folks take time to closely examine the fascinating and intricate arrangements of cactus spines. Glandulicactus wrightii, which is native to Texas and adjacent Mexico has amazingly long, hooked spines that resemble cat whiskers. Long term winter hardiness is hopeful here in Zone 7b, since the seed from which this was grown came from a population at 5,000′ elevation on the New Mexico/Texas border.
Just finished flowering in our crevice garden is the amazing member of the Amaryllis family, Acis ionicum. This little-known Albanian snowbell hails from small areas of Coastal Albania and Western Greece, as well as a few of the adjacent islands. The flowers of this species are quite huge, compared to the better known A. autumnalis. In the wild, Acis ionicum grows in rocky, calcareous hillsides, so it feels right at home in our recycled concrete crevice garden. Hardiness is probably Zone 7b and warmer…at least.
We love the miniature silver mats of Antennaria parviflora (little-leaf pussytoes). This little-known North American native (Canada south to Arizona) forms a tiny, 1″ tall groundcover that’s hard to the touch. In spring, the patch is topped with short fuzzy spikes of brush-like white flowers. The plant below, which measures 1′ in width, is only 18 months old from seed, and is growing in our rock garden in a well-drained mix of 50% Permatill. Hardiness is Zone 4b-7b.
I’ve been surprised to see the black swallowtails regularly enjoying the nectar of the summer-flowering daphnes…in this case, Daphne x napolitana ‘Bramdream’. Our plants are thriving, growing in our full sun rock garden.
Most highly prized rock garden plants originated somewhere other than the Southeast US. One notable exception is Bigelowia nuttallii, or if you prefer common names, Nuttall’s rayless goldenrod. This fascinating plant resembles a whisk broom that just swept up a spilled bottle of mustard.
Named after English botanist/zoologist Thomas Nuttall (1786-1859), who lived in the US from 1808 until 1841, this fascinating plant, grown by rock gardeners worldwide, is native in only a few locations from Georgia west to Texas.
Bigelowii nuttallii makes a tight evergreen clump of needle-thin leaves, topped from mid-summer until fall with 1′ tall sprays of frothy yellow flowers…yes, those are actually flowers, but without the typical showy “rays”. Full sun for at least half a day, and good drainage are the key to success with this very easy native perennial. Hardiness is Zone 5a-9b.
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.
Here’s a photo this week of one of our favorite North American native plants, Juniperus horizontalis ‘Copper Harbor’. This would certainly add significant year round color interest to any native plant garden. In our trials, this is far and away the best of the golden Juniperus horizontalis cultivars. We offered this selection for a couple of years, but there seemed to be little interest.
It fascinates us that such a widespread native like Eustoma exaltatum isn’t more widely grown in gardens. Often known by the common names prairie gentian or lisianthus, eustoma is prized by flower arrangers, but not gardeners. Eustoma is native from coast to coast…Florida to California, and north to the Canadian border in Montana.
In the wild, Eustoma exaltatum is a short-lived perennial that can also behave as a biennial or even an annual in some sites. The key is to plant it where it can happily reseed as we have done in our gravelly crevice garden, which is odd, since in the wild, they are found in moist meadows and streamsides.
Below are our plants in peak flower now, during the brutal heat of summer. So far, we’ve struggled to keep this happy in a container, in the hopes we could make this available, but we continue to try.
Commercially, eustoma has been hybridized ad nauseam to create better cut flowers, but these hybrids seem to have lost all of their perennial nature compared to the wild genetics. Our plant pictured below is the large (2′-3′ tall) subspecies russellianum from wild collected seed from Bastrop County, Texas.
We are in love with the long-flowering Thymnophylla pentachaeta var. pentachaeta ‘Laredo Gold’, which graces us with masses of gold flowers from spring through fall, in our sunny, dry rock garden. This Patrick McMillan collection comes from a population in Texas. Not only is this short-lived, southwestern US native reseeding perennial great in flower, but the native Navajo Indians also used it as a drug for people who want to dream of being chased by deer….we are not making this up!
We are enjoying the rare Penstemon baccharifolius this summer in our high/dry crevice garden. This species is native to limestone ledges up to 6,500′ elevation from the Edwards plateau in Texas south into Northern Mexico. This species hates our summer rains, and we had given up on growing this until we built our alkaline crevice garden a few years ago. Now it thrives, growing in 3′ deep Permatill gravel.
We’ve long collected conifers of the genus Chamaecyparis (false cypress). We grow all six recognized species, but the one which is best represented in horticulture is Chamaecyparis obtusa (hinoki cypress). Selections from this species range from giant 100′ specimens to tiny dwarfs.
Our favorite has to be the the dwarf Chamaecyparis obtusa ‘Juniperoides’…the juniper-like hinoki cypress. Introduced from the UK around 1920, this century old selection has yet to be surpassed. Below is our 23 year-old specimen this spring, which thrives in our un-irrigated rock garden, planted among agaves, having achieved the massive stature of 2.5’ tall. This is certainly not where we usually recommend planting hinoki cypress, since many cultivars don’t thrive in western sun, especially without any sign of irrigation. This plant, however, continues to amaze us without any browning typically seen with chamaecyparis grown in the combination of sun and bone dry soil.
We’ve grown quite a few stachys (pronounced stay-kiss) through the years, but have been most impressed this spring with our newest acquisition, Stachys cretica. This fascinating dryland perennial has a wide natural range from France to Iran, where it thrives in rocky, dry, Mediterranean-like conditions. Our plants are seed-grown from Greek Plantsman, Eleftherios Dariotis, who will be speaking at our upcoming Southeastern Plant Symposium.
Stachys is one of the largest genera of plants in the sage (Lamiaceae) family, with estimates ranging from 300 to over 400 species. Stachys species are spread worldwide, being found from Europe though Asia, Africa, and into North America.
Shockingly, Stachys cretica seems virtually unknown to most gardeners, despite it puttig on a killer floral show in an unirrigated bed, and being foraged in our garden, by a huge number of bumblebees.
It’s been quite a floral extravaganza this spring in the dryland garden sections. Here are the latest of our flowering barrel cactus that have bloomed recently at JLBG. All of our cactus are growing outside without any winter protection in our zone 7b garden. The key for most is simply good soil drainage.
Just over a year ago, we built a new berm garden, adjacent to our Open House welcome tent. Here is that garden today. The soil is composed of 50% Permatill (slate gravel), 25% compost, and 25% native soil). This is in an unirrigated section of the garden. Like all garden spaces at JLBG, no commercial fertilizers are ever allowed. The exceptional drainage and high nutrient content from the compost and Permatill result in an amazing growth rate.
Delosperma cooperi and Delosperma ‘Kelaidis’ have formed a lovely union in our crevice garden, where they grow in pure Permatill gravel. The key to growing ice plants in a hot, humid, rainy climate is excellent drainage.
Looking great in the crevice garden this month is the Pacific Northwest native, Dichelostemma ida-maia This odd little bulb is a member of the Asparagus family…so that makes it as cousin to agaves, hostas, and asparagus. In the wild, it is only found in coastal meadows and into forest edges and partial woodland openings in Northern California and Southern Oregon. As a rule, California natives typically aren’t climatically welcomed in the rainy Southeast US, but Dichelostemma ida-maia is an exception.
Clematis vinacea is a recently described species of non-vining clematis, published in 2013 by plantsman Aaron Floden. In the wild, it grows in a small region on the border of Eastern Tennessee/Northern Georgia. Closely allied to Clematis viorna/Clematis crispa, Clematis vinacea is a compact, non-climbing species. For us, it makes a sprawling mound to 18″ tall x 4′ wide that flowers from May through summer. In habitat, Clematis vinacea prefers a dry, alkaline site, but it has shown good adaptability to slightly acidic soils in our trials.
The Greek bellflower, Campanula formanekiana has been superb in the crevice garden this spring. This amazing monocarpic (dies after flowering) species take three years to flower, and when it does, it puts on one heck of show. It’s namesake was Czech botanist, Eduard Formanek (1845-1900). We’re hoping for a good seed set. Hardiness is Zone 7a-9a, at least.
Nierembergia ‘Starry Eyes’ is looking particularly dazzling in the rock garden at JLBG. Starting to flower for us in late April, this incredible gem is from our 2002 botanical expedition to Argentina. I distinctly remember walking by as our friends from Yucca Do Nursery extracted a small piece of this nierembergia with only a single flower attached. I remember thinking to myself how poorly nierembergias, in particular Nierembergia repens perform in our climate and how I wouldn’t have wasted my time on such a plant. Two decades later, boy was I wrong!
In our climate, Nierembergia gracillis ‘Starry Eyes’ blooms continually through the summer months. It thrives in full sun and a well drained, gravelly soil. Thank you Yucca Do, for all the great introductions!
The crevice garden has “woke” for spring, with early flowering plants in full gear. Here’s a shot of one small section, featuring Delospema dyeri and Iberis simplex (taurica). We hope you can visit in person for the second weekend of our spring open house, May 6 – 8, 2022.
Spring is unquestionable peak cactus flowering season at JLBG. Although many of you are familiar with our large opuntia (prickly pear) collection, we thought we’d focus on the more diminutive barrel cactus, which you will see if you visit during our spring open house. Keep in mind that most close at night, not reopening until 10am-noon the following day. The photos below are just a tiny sample of the cacti that will be in flower.
I fell in love with puccoons several decades ago, when I first saw them growing on the Michigan dunes as I hiked around the shoreline. I was immediately smitten with this native member of the Borage (pulmonaria) family. There are 21 different species of Lithospermum (puccoon) in the US, where some go by the common name, stoneseeds.
It would take me five transplant attempts over the next three decades before we were able to successfully get one established in the garden. The photo below is our collection of Lithospermum caroliniense (hairy puccoon) from East Texas, flowering now in it’s new home adjacent to our crevice garden. This species is partial to acidic, sandy soils, so our next task is to figure out what other conditions it will tolerate and then to get it propagated, so we can share.
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.
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!
Mukdenia is an odd monotypic genus in the widespread Saxifrage family, along with cousins heuchera, tiarella, and the namesake saxifraga. The odd genus name honors the former city of Mukden in Manchuria, which is now known as Shenyang. Mukden was the site of the largest modern day battle, prior to WWI. In case you missed it, the final score was Japan 1, Russia 0.
Several on-line sites, including that purveyor of accuracy, Wikipedia, proclaims there to be two species of Mukdenia, which is sadly incorrect. Although I’m sure Mukdenia rossii would like a sibling, one simply does not exist. I think of Mukdenia like Smucker’s…with a name like that, it has to be good…and it is.
Mukdenia naturally resides in China and Korea, where it can be found in some rather inhospitable places. I had to laugh when I read countless on-line articles that repeat the myth that mukdenia needs water during summer drought. It certainly doesn’t mind summer water, and will probably look better as a garden specimen with some irrigation. My first encounter with mukdenia in the wild was in fall 1997 on South Korea’s Mt. Sorak, where it thrived, growing in the rock cracks of a nearly vertical cliff (below)
When we built our concrete crevice garden, mukdenia was one of the first plants I wanted to plant to see if it would mimic what I had seen in the wild. Below is our 2017 planting of Mukdenia rossii ‘Karasuba’ in late March/early April 2022, as it emerges in flower. The foliage continues to expand around the flowers. Our plants get 3-4 hours of sun each morning, then shade the remainder of the day. Winter hardiness is Zone 4a-7b.
The South African (Eastern Cape) Bergeranthus vespertinus has been absolutely fabulous this late winter/spring season. Here it is growing in one of our rock gardens, where it is mostly protected from winter moisture. (Hardiness Zone 7b and warmer…at least)
Not only did we have 100% survival on our living stones (Lithops aucampiae ssp. koelemanii) in the garden, despite low temperatures of 15-16 degrees F, but they are now in the process of splitting, which is sort of like giving live birth. Splitting happens after flowering, and followed by a subsequent dormancy. The plant divides and the new plants absorb the of the old foliage…sort of like The Blob movie. We were fortunate to catch the process visually for the first time this week.
My visit to Crete in 2010 was eye-opening when I observed that most native daphnes of the region grew in full sun among rock, in the driest conditions imaginable. That prompted us to re-try many of the daphnes that we’d killed years earlier…obviously, with too much kindness. Now, all of our daphnes are planted in baking sun in our crevice garden, or similar rock garden conditions. Here are a few photos at JLBG from early April.
The first is the Mediterranean native, Daphne collina, which most authorities now subsume under Daphne sericea. All daphne pictured below should be hardy from Zone 6a – 8b.
Daphne ‘Rosy Wave’ is a Daphne collina hybrid with Daphne burkwoodii
Daphne x napolitana ‘Bramdream’ is a hybrid of Daphne collina and Daphne cneorum.
Flowering now in the rock garden is the European native, Anthyllis coccinea…aka: red kidney vetch. This small rock garden legume (Fabaceae) is still in its first full year in the ground, having been planted last June…so far, so good.
Antennaria solitaria, the solitary pussytoes is looking great in the garden this week. This amazing native groundcover hails from Ohio south to Alabama, where it can be found in open shade or part sun, but always in dry soils. Despite being native in acidic soils, our plants below are thriving in our alkaline crevice garden.
In our cold frames, some plants will occasionally flower out of season, and that’s the case this week when one of our Orostachys ‘Crazy Eddie’ plants decided to flower out of season…fall is it’s normal time. The offseason timing won’t adversely affect the plant, and it did give us an unexpected photo moment. Because of the form of the flower, orostachys gained the common name, dunce caps, named after the pointed caps that poorly performing students were forced to wear. Of course, you’re probably showing your age if you knew what dunce caps were.
Most hardy cactus have the good sense to wait until spring to flower, but not Notocactus haselbergii. This gem, which hails from Southern Brazil, started to bloom the first of March, and will continue on and off most of the summer. It has thrived for several years in our crevice garden.