Meet Urophysa

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.

Stingray in the Garden

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.

Red China

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.

The King’s Arum

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.

Mangave zombies

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.

Unduly Undulate

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.

Winter Onions

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.

In celebration of the obscure

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.

Been Watching the Stones

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.

Can you say Poo-yuh?

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