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.
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.
The gigantic, winter hardy, North American native, cow tongue cactus, Opuntia lindheimeri ‘Linguiformis’ is looking wonderful in the fall garden. We planted our original plant back in 2000, but when reworking a bed, needed to move it about 4 years ago. We took a couple of pad cuttings which languished, laying bare root on a bench for nearly 2 years. Despite this abuse, this is the result two years after those cuttings finally went in the ground. We find this to be the largest of the Zone 7 winter hardy prickly pear cactus, maturing around 7′ tall x 12′ wide. Winter hardiness is at least Zone 7b-10b, and perhaps colder.
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 like the rock group of the same name, these fascinating living stones also look quite old and wrinkled. The genus Lithops are tiny succulent plants native to the deserts of South Africa. Despite virtually all references on-line, they make great garden plants…as long as you have a crevice garden, and grow them when they will not receive any rain in the winter months. These are 4 1/2 years old from seed.
Our plants of Lithops aucampiae have just started their flowering season last week, having sailed through winter temperatures of 16 F last winter, and seemingly enjoyed our hot, humid summers. We’re hoping for single digits F this winter, so we can really put them to the hardiness test. In the meantime, we’ll enjoy the fall flowering season.
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.
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.
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.
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.
We’ve got a thing for hardy cactus in the garden, but haven’t propagated many to offer yet. One of our many favorites is Notocactus apricus. Above is our 17 year old clump in the garden, which is 4″ tall x 15″ wide. We’ve grown a few from seed, but are curious how many folks might consider purchasing one? We’ve only been to 7F since 2000, so we don’t know if it will take colder temperatures or not.
Visitors to our spring Open Nursery and Garden this year got to see the amazing Trichocereus ‘Irridescent Watermelon’ (bred by local cacti specialist, Mike Papay) in full flower (hardy so far to 7 degrees F). Offsets are almost non-existent, so we decided to grow some from seed. Each plant will be different, but all should be quite nice. So, if we offered these as a seed strain, would you purchase some, knowing each will be slightly different?
One of our favorite spring ice plants is flowering now in our rock garden, Delosperma ‘Kelaidis‘. Growing only a few inches tall, it likes hot, baking sun and good drainage. Selected in Colorado, its hardiness is Zone 4-8a.
The amazing Balkan native Genista saxitalis is in full flower today. This amazing groundcover has been brightening our rock garden for a couple of weeks. Genista is easy to grow with plenty of sun…hardiness is Zone 4a-8b.
For those who didn’t get to our Open Nursery and Garden last week, here are some of the hardy cactus you missed in the new Souto Garden section. We’re passionate about hardy cactus, and have been so since we were hooked by a jumping cholla about 45 years ago. I hope you enjoy the photos of this amazing group of plants.
Echinocereus reichenbachii var. caespitosus
Echinocereus triglochiditis v. mojavensis
Gymnocalycium ‘Bridal Showers’ – a Mike Papay hybrid
Gymnocalycium ‘Panama Pink’ – a Mike Papay hybrid
Opuntia basilaris v. aurea ‘Golden Carpet’
Opuntia ‘Claude Arno’
Opuntia polycantha ‘Crystal Tide’
Opuntia polycantha var. hystracina
Opuntia ‘Little Monk’
Opuntia sp. nov. pink flowers
Trichocereus ‘Big Time’ (a Mike Papay hybrid of T. bruchii)
Trichocereus ‘Irridescent Watermelon’ – a Mike Papay hybridTrichocereus bruchii
While gardeners in colder zones take growing hens and chicks for granted, those of us in hot, humid climates are thrilled when we find a variety that lives for us. Here is a photo from the garden today of one of the best in our climate….Sempervivum ‘Oh My‘.