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.
A couple of weeks ago, we mentioned our landscaping project on the north side of Mt. Michelle to create more intricate planting pockets, while raising the planting heights significantly via the use of rock assisted berms.
Phase 2 of the project was to create a cut through on northwest side through a previously inaccessible bed. Phase 2 is now complete, and visitors can now traverse the new path, exiting into the northwest side of the Mt. Michelle waterfall. This path takes you under the large speckled-leaf loquat, Magnolia macclurei, and several large conifers, so be sure to look up as well as down.
Last week, Jeremy and his staff tackled phase 3 of the project, which was the two 50 degree slopes on the west side of Mt. Michelle. Despite being planted for some time, we had lost some soil due to runoff, and the plants were screaming for more compost, and we were screaming for more rock pockets.
In less than a week, Jeremy’s team stacked these new retaining planting walls, which provide hundreds of new planting pockets for small woodland treasures. Each is now filled with our garden compost mix as well as an array of small, little-known plants. Just remember, if you garden on flat ground and think you are out of planting space, the key is to learn to think like a Pythagorean…a² + b² = c²…go vertical.
You’ll be able to see these newly planted areas during our winter open house, although it will take a while for the plants to mature.
One of our winter garden favorites is looking so good right now, that we had to share. Oxalis palmifrons is an amazing, but slow-growing rock garden gem, that hails from the South African karoo. We offered this through Plant Delights almost a decade ago, and it will be some time before we have enough to offer again.
If you’ve visited JLBG, you know how much we love working with rocks, so we continue to find new areas to plant more. We’ve recently tackled two long overdue projects near the Mt. Michelle waterfall.
The first was re-working the Mt. Michelle watercourse we know as Mystic Creek (named after one of our late cats). When this was installed in 2003, we used concrete to form the water channel. Well, after 18 years, tree roots had their way with the concrete, which lost both the battle and the war.
After a fair amount of root excavation work, Jeremy and Nick installed a new rubber liner, with rocks along the edge. We’ll probably wait until spring to finish the replanting in order to avoid planting on top of something that was winter dormant. Below is the new rocked watercourse.
Phase 2 of the project was re-working an adjacent bed, where light levels had changed dramatically since it was installed in 1998. Originally a full sun bed, the shrubs on the west side have grown substantially, leaving us with a bed that only gets 3-4 hours of sun on one end, and a full shade area underneath the canopy.
Here, we raised the center of the bed, with more of Jeremy and Nick’s rock work, which was then filled with our on-site created compost. This created a visual barrier to much of the winding path that visitors use to get closer to the small plants, which are now tucked in the crevices.
One the back (west) side, Jeremy and Nick installed another small rock seating area, of which there are never enough.
There are a few more days of rock work to complete Phase 2, then we’ll start on Phase 3, which will rework the west face of Mt. Michelle, with more boulders to create additional planting pockets. We hope you’ll check out the progress at our upcoming winter open house.
We have long loved small crevice-sized succulents, but have also killed far more than our share, due mostly to our wet, cold winters. The newest star in our trials is the South African, Rabiea albipuncta, a first cousin to the better known, Delosperma. We should mention, that new DNA research has actually suggested a name change to Nananthus vittatus would be more correct, so we’ll be re-tagging shortly.
This gift from Denver Botanic Garden plantsman extraordinaire, Panayoti Kelaidis, has thrived in the gardens since 2018. We actually tried this back in 2004, but our site simply didn’t drain well enough in winter. This image was taken here at JLBG on February 2 this year, which shows how insanely tolerant the flowers are of cold weather. We hope to make this available next year through Plant Delights Nursery. This gem forms a substantial caudex, and as such is highly prized by bonsai enthusiasts.
Here is the reportedly tender Massonia depressa from South Africa in full flower in our crevice garden. I should add that this photo was taken 2 nights after we recorded 16 degrees F. I guess when the source of all worthwhile information, Wikipedia, says “When cultivated in a temperate environment, M. depressa does not tolerate freezing temperatures, so must be grown under glass in a cold greenhouse or similar.” we should take that as fake gardening news. Hmmm.
Massonia is a genus of bulbs in the Asparagus family, related to the more familiar genus scilla. Winter hardiness of this species is….well, still to be determined, but we’re good to at least Zone 8b so far.
Unless you’re a serious plant nerd, you’ve probably never heard of the plant genus, Urophysa. This small genus of only two species in the clematis family (Ranunculaceae) is only found growing in Karst cliff crevices in a few limited provinces of South Central China. In other words, they are quite rare. Urophysa henryi was originally named Isopyrum henryi, when it was thought to be a brother of our native Isopyrum biternatum. Urophysa is now considered most closely related to the famed half-columbine, Semiaquilegia adoxoides.
While the Chinese people mostly use Urophysa henryi as a medicinal treatment for bruises, etc., we prefer it as a winter-flowering gem in the rock garden. Here are our plants, which began flowering in our rock garden, just as we turned the page on the new year, 2022.
One of our favorite winter hardy (Zone 7b) century plants is the non-spiny Agave bracteosa ‘Stingray’. Here is one of our garden specimens this week, which has been thriving in the ground since 2016. Unlike most agaves, which prefer full sun, Agave bracteosa is better in part sun (full sun for only a few hours during the day). Agave bracteosa ‘Stingray’ is also a fairly slow grower that only produces a few offsets. A mature rosette will top out around 15-18″ tall x 2′ wide. We love the unique texture, which differs from all other agaves.
The dwarf groundcover Sedum tetractinum ‘Little China’ is superb throughout the growing season, but we particularly love when cold weather arrives and the olive green foliage turns to bright red in the sun…what a superb winter show. Hardiness is Zone 4a-8b.
One of the last plant exploration trips the late plantsman Alan Galloway made, was to Majorca, Spain. Alan was so excited to return home with some special selections of the fall-flowering Arum pictum, which typically has solid green foliage…except on Majorca. This beautiful form is known by collectors as Arum pictum var. sagittitifolium, although the name isn’t considered valid due to the natural variability in leaf patterns. This is Alan’s favorite form from his trip, to which we added the cutlivar name, A. pictum ‘King James’. It seems that back when Majorca had kings (thirteenth and fourteenth century), before its merger with Spain, they had a propensity for naming most of them, James.
One of many great attributes of mangaves, compared to one of their parents, agaves, is that they don’t die after flowering. Agaves are mostly monocarpic, which mean that they behave like bromeliads, where each rosette grows to maturity, then dies after flowering. Those species of agave which offset, live on after flowering, by means of un-flowered offsets. Those agave species which don’t offset are a one and done after they flower and reproduce by reseeding.
By incorporating manfreda genes to create xMangaves, the monocarpic trait disappears. After a mangave flowers, it dies to the ground, but like a good zombie, it soon pops back from the dead. Here is a current photo from the garden of two clumps of xMangave ‘Blue Mammoth’. The first, larger clump has not flowered, but should do so next year. The second clump with all the offsets, flowered in 2020, and re-grew to this point in 2021. Next year, the rosettes will continue to re-grow in size.
Most plants have Latin name epithets (the 2nd word) that describes/commemorates either a place, person, or plant characteristic. In this case, the foliage of this Greek wooly mullein (Verbascum undulatum) is ridiculously wavy. Here it is looking great in our rock garden during the early winter. This will be our first full winter with it in the ground, so fingers crossed that it survives.
Starring in the rock garden in early December is the amazing Allium virgunculae ‘Alba’. This delightful dwarf allium to 8″ tall is similar to the better known and slower offsetting Japanese Allium thunbergii. Allium virgunculae, which typically has lavender flowers, hails from Japan’s far south Kyushu Island.
It’s hard to imagine a plant more obscure that the Southeast coastal native Houstonia procumbens. You may recognize the name houstonia as belonging to one of the many more common bluets. Instead, this is a creeping white-et. We’ve had this in our alpine rock garden for a couple of decades, but barely notice it until November, when the flowering picks up as other plants around it are going dormant. In the wild, Houstonia procumbens can be found in moist pine savannahs as well as nearby disturbed habitats. We’re unsure if this is showy enough for anyone to actually purchase.
We’ve tried growing living stones (Lithops) a few times over the last decade in the garden, but could never get them to last longer than a couple of years. We weren’t loosing them to cold temperatures, but to moisture. So, when we built the crevice garden, lithops were one of the first plants we wanted to try again. We designed the crevices with overhangs to keep water completely off certain special plants, and that’s where we planted our seed-grown living stones.
For those who haven’t grown these irresistible gems, Lithops are South African succulents in the Azoiceae family, native to very dry and mostly tropical regions. They are prized for their odd appearance that consists of only two camouflouged succulent leaves.
We’ve never been able to coax a lithops to flower until last week. In their new crevice home, several finally decided to bloom this fall, with a sucession of flowers that still continues. We are currently growing only one species, Lithops aucampiae, but now that we’ve been successful, we’ve planted seed of more species to try. It takes us about 18 months from seed to get a plant large enough to go into the garden.
Despite everything written about lithops being tropical, we have not found this to be the case. Like so many plants, not enough people have been willing to experiment in colder climates in the right conditions. Of course, if you believe everything written on line, you’ll know for sure that they can’t take anything below 40 degrees F. Hint…ours have made it fine in the garden to 13F, so we expect them to tolerate even colder temperatures if kept dry. Wish us luck and be sure to check out the stones growing in the crevice during our next open house.
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.
One of our favorite of the US native (Central Texas) desert ferns is Pellaea ovata. Here is our clump in the crevice garden looking quite nice this week. This is scheduled to return to the Plant Delights catalog in January. Hardiness should be at least Zone 7b and south.
Tis the season for prickly pear harvest. Many of our early ripening prickly pears are beginning to change from green to red, providing a lovely feature in the fall garden. Here is our clump of Opuntia pyrocarpa this week. We hope everyone’s prickly pear is growing well from our giant prickly pear pad giveaway at our annual Summer Open Nursery and Garden.
Try as we might, we have been epic failures trying to grow the showy southwest native Zauschneria (now epilobium) in our garden, due to the combination of high humidity and torrential summer rainfalls. No matter where we tried them in the rock garden, they quickly expired. That was in the years BC…before crevice. Here is our plant of Zauschneria canum var. arizonica ‘Sky Island Orange’, a David Salman selection, planted in early 2018 and still thriving in our urbanite crevice garden. Not bad for a plant that doesn’t grow here.
We admit to a long-standing case of buckwheat envy. Every visit to the worlds great rock gardens, such as the Denver Botanic Garden, leave us lusting to grow the rock garden genus, eriogonum. We’ve killed many members of the genus, since they truly hate our humid and wet summers. Even our crevice garden was no help in keeping these alive, even including our reportedly easy-to-grow Appalachian native, Eriogonum allenii. After almost giving up several times, we can finally declare success with the Texas native Eriogonum longifolium, from our East Texas botanizing expedition. Here’s our clump in full flower, and quite happy in one of the rock garden sections. Granted, it’s not as stunning as some of the species that thrive in Denver, but hey, we can now check that genus off the list.
We are fascinated with the wonderful genus zephyranthes (rain lilies). Zephyranthes are unobtrusive, summer-flowering bulbs that can fit in any garden, with a flower color ranging from yellow to white to pink. The great thing about zephyranthes is the lack of large foliage that often accompanies many other spring-flowering bulbs, so site them in the front of the border, or in a rock garden to be best appreciated.
Zephyranthes are one of our specialty collections at Juniper Level Botanic Garden, with 25 species and 257 unique clones. Here are a few of the zephyranthes blooming this morning in our alpine berm. You can view our entire zephyranthes photo gallery here.
Looking nice this week is this cool selection of the North American (Northern Mexico) native Manfreda undulata. All commercial forms of this are heavily spotted, but we really love this this amazingly rippled-leaf form that we picked up at Bob Brown’s wonderful UK nursery a few years ago on a UK plant roundup trip. We’ve named this seedling, Manfreda ‘Crested Surf’. Hardiness should be from Zone 7b south.
Looking good this week is Nierembergia ‘Starry Eyes’. We have special memories watching our friend Carl Schoenfeld collect cuttings of this on our 2002 botanizing trip to Argentina. While it’s only reliably winter hardy to Zone 8, it’s a flowering machine during the summer. Here it is growing in our new crevice planting near our Open House welcome tent.
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.
Our patch of Aloe cooperi has been beautiful in flower this summer, but every time I see it, my mind automatically associates it with rocker, Alice Cooper. I guess he made quite an impression on me as a child. Aloe cooperi is the hardiest of the aloes, first cousin to the better known Aloe vera. Aloe cooperi has been fine here in Zone 7b for decades, but we doubt it would be winter hardy much further north.
Most keen botanist are familiar with the late French botanist, Andre’ Michaux (1746-1802). Michaux was a pioneer in botanizing North America, but how many people have actually grown the plant genus named in his honor. Michauxia is a genus of seven species, sister to campanulas, that hail from the Mediterranean though much of the Middle-East. We are fortunate to have his namesake, Michauxia campanuloides in flower this week for the first time, where it is thriving in the crevice garden.
Here are a couple more cactus hybrids flowering in the gardens of JLBG, both created by our volunteer cactus/succulent curator, Vince Schneider. The first is a Trichocereus cross, the parents of which were created by a former volunteer, Mike Papay. Vince crossed two of Mike’s selections to come up with the gem. My camera had trouble since I don’t think this color is supposed to exist in nature.
The second is Vince’s cross of Echinocereus dasycanthus x ctenoides…an amazing blend of colors. We can’t imagine anyone with a dry sun garden that isn’t growing these amazing plants.
To identify plants that are new to us, we start with the time-tested step of determining how close plants look to relatives we already know. This comes first, before we dive into floral dissection, etc. In most cases, we can get pretty close to a correct id, since we’ve grown and seen such a large number of plants. Two plants that threw us completely off the trail when we first saw them, are flowering now in the crevice garden here at JLBG.
The first, below, is Digitalis obscura, the Spanish Foxglove. I’d have lost big had I wagered on its identity when I first saw this, since I would have bet the farm that it was a penstemon, since the flowers and foliage share such an amazing resemblance to that genus. It’s taken us years to find a spot well-drained enough for this to survive in our rainy, humid, climate, but the wait was worth it.
The second plant that doesn’t seem to fit its genus is also flowering now in the crevice garden…Penstemon ambiguous. This Southwest/Great Basin native, known as sand beardtongue, looks nothing like other members of the penstemon family, which are usually easily recognizable at first glance. Instead, it could easily be mistaken for a phlox. This is our third year for this gem, so perhaps this may appear in our nursery offerings one day.
Most people are in too much of a hurry when they visit gardens and subsequently miss so many of the tiny gems in the garden. Here our clump of the South African native Ledebouria inquinata that was in full flower in the crevice garden during our recent spring open house. I wonder how many people actually walked slow enough to notice this tiny gem and its massive floral show. How about a “slow gardening” movement?
Here are more delospermas (ice plants) looking great at JLBG this week. The first two are the most moisture tolerant, Delosperma cooperi (purple), and Delosperma ‘Kelaidis’ (peach). At the bottom is Delosperma sutherlandii, which is a species that we’ve never been able to keep alive in our wet summers prior to building the crevice garden.
We’ve tried for years to grow Helianthemum, the European native rock rose, which is highly prized by rock gardeners. Over the last 35 years, we’ve failed miserably…until we built our crevice garden. Here, it is currently, thriving in our soil mix of 50% Permatill (popped slate).
Allium ‘Ostara’ is a new bulbous ornamental onion from a cross of the lovely, but difficult to grow (in the southeast US) Allium karataviense and Allium atropurpureum. We’re growing this in our crevice garden, which is working well…so far. We’re hoping the genes from Allium atropurpureum will make this more growable.
Looking truly superb this spring is the South African ice plant, Delosperma dyeri in the crevice garden. We can’t grow this in typical soil due to our high rainfall, but in our crevice garden where gravel is the main planting media, it performs like a champ.
While daphnes have a reputation for being tough to grow, many are actually quite easy if given proper siting. My life with daphnes changed significantly after my 2010 botanical expedition to Crete. I was shocked to find daphnes growing in full baking sun in bone dry regions among large rocks. Before then, I had obviously taken far too good care of my daphnes. Once we constructed the crevice gardens at JLBG, we replaced all the daphnes we’d killed in “better” garden locations. Here’s the Cretan native Daphne sericea in full flower.
Yes, cactus flowering season has begun at JLBG with our two earliest specimens. Both Notocactus hasselbergii from Argentina and Pediocactus simpsonii from the Western US are the first two to bloom each season. We should have an incredible cactus flowering this year, which should still be in full swing for our spring Open Nursery and Garden days.
There are several tiny rock garden-sized phlox, bred in the EU, and sold by specialist nurseries as forms of the Western US native, Phlox douglasii. The only problem is that Phlox douglasii isn’t really growable much outside climates similar to its native haunts. Phlox expert Charles Oliver determined these are actually hybrids between Phlox douglasii and the East Coast native Phlox subulata. This week, one of those hybrids, Phlox ‘Ochsen Blut’ is ravishing, and thriving in our crevice garden. The name, which translates to Ox Blood, indicates that the breeder most likely doesn’t have any training in marketing.
Unless you’ve been hiding under a piece of concrete, you’ve no doubt heard of our crevice garden experiment, constructed with recycled concrete and plants planted in chipped slate (Permatill). It’s been just over three years since we started the project and just over a year since its completion. In all, the crevice garden spans 300′ linear feet and is built with 200 tons of recycled concrete. The garden has allowed us to grow a range of dryland (6-12″ of rain annually) plants that would otherwise be ungrowable in our climate which averages 45″ of rain annually.
One of many plants we’d killed several times ptc (prior to crevice) are the arilbred iris, known to iris folks as ab’s. These amazing hybrids are crosses between the dazzling middleastern desert species and bearded hybrids. Being ready to try again post crevice (pc), we sent in our order to a California iris breeder, who promptly emailed to tell us that he would not sell them to us because they were ungrowable here. It took some persuading before they agreed to send our order, but on arrival, they became some of the first plants to find a home in the new crevices. Although we’ve added more ab’s each year, the original plantings will be three years old in August. Here are a few flowers from this week.
Iris are just a few of the gems that can be found in our “cracks”, continuing below with dianthus. As we continually take note of our trial successes, more and more of those gems will find their way into our catalog and on-line offerings…as long as we can produce it in a container. Please let us know if any of these strikes your fancy.
If that’s not enough, here are some more shinning stars currently in bloom.