I stopped in at the Sherman Gardens recently to check in on the succulent garden, which I visited a couple years ago and wrote about here. Although that garden looks the same as the day I visited, there was a stunning newcomer elsewhere on the grounds, in a couple pots on tall pillars.
Clianthus formosus aka Swainsona formosa, Sturt’s Desert Pea
The brilliant flowers were as noisy as parrots and pulled me in from 50 yards away. I was guessing some kind of erythrina. Up close I could see that the leaves were as subtly beautiful as the flowers were flamboyant. The foliage had the typical, finely cut stamp that all members of the pea family possess, such as lupins, but grey and fuzzy like Dorycnium hirsutum. Offhand, I can’t think of another plant that combines flowers in the colors of the tropics with leaves that would look at home in any mediterranean landscape. The flaming blooms ignite against those pewter leaves, and the red stems spread the flames horizontally. A staff member helped me with the identification but knew little more than a name. She said she noticed them on the truck during a recent plant delivery and grabbed four of them, two for pots, two to trial in the ground.
By this point I already had clianthus penciled in for summer 2014.
Not so fast. I found this description and alarming bit of advice from Chiltern’s, which carries seeds of this clianthus: “A magnificent, semi-procumbent, evergreen sub-shrub with silky-haired, pale grey-green foliage and large scarlet flowers with a bulbous, velvet-black eye. Although it can be grown on its own roots, it then has a habit of dying just before it flowers. However, it has been found that if grafted as a young seedling onto a similar seedling of Colutea arborescens, it grows and blossoms much more freely and lives longer. We therefore offer a packet of each of these together with full instructions to give your green fingers a real test of skill.”
I hate tests of skill.
That it’s tricky to grow explains why a beautiful plant first collected in 1699 is not more commonly seen.
“a creeping vine that runs along the ground … and the blossom like a bean blossom, but much larger and of a deep red colour looking very beautiful.”
— collected by British navigator William Dampier in 1699 on Rosemary Island.
Image found here
The Royal Botanic Gardens, Kew, has a lengthy online description of this striking Australian and doesn’t mention any special growing requirements. The Australian National Botanic Gardens gives both reassuring yet still challenging propagation advice for the floral emblem of South Australia:
“The hard seed coat of Sturt’s Desert Pea inhibits germination. This effect can be overcome by filing or nicking the seed coat away from the ‘eye’ of the seed; alternatively, the seed may be rubbed gently between sheets of sandpaper. Soaking the seed in warm water gives variable results, Boiling water should not be used as it destroys beneficial bacteria on the seed coat. Since the seedlings develop a long tap root and do not tolerate root disturbance, treated seeds should be planted directly into the chosen garden site or container, or alternatively into small pots for transplanting soon after germination.
“Full sun, perfect drainage and protection from snails are essential. Supplementary watering may not be necessary once the seedlings are established. Under ideal conditions flowering commences about four months after germination. Sturt’s Desert Pea is usually treated as an annual but vigorous flowering may result if root crowns survive from one season to the next. Alternatively, it may be grown in large drums, tubs and upright terracotta drainpipes which allow adequate root development.”
Clianthus formosus, Sturt’s Desert Pea, an Australian beauty for the brave and those craving a test of skill. I’ll take mine in a 4-inch pot, please.