Plant of the Month

POM March

Drypoteris – Far From Marginal

Deservedly, the various species and cultivars of Sedum have been a main staple within the gardening community for centuries.  Like many of the better known plants within the gardening community, it was a plant that garnered my infatuation early in my career and only grew as my understanding of the genus expanded.   With over 600 species native to temperate and warm arid regions throughout the northern hemisphere, this is indeed a genus that commands recognition!
Sedum is a member of the Crassulaceae or Jade Plant family – a family known for very tough plants! The etymology of Sedum stems from the Greek Sedere, which means to sit, referencing its ability to perch or sit atop rocks and buildings.  Carl Linnaeus (1707-1778) officially penned the name in 1753, but he cited Lucius Junius Moderatus Columella (4-70 AD), who mentioned Sedum in his 12 volume treatise on Roman Agriculture named Rus Rustica. However, it is uncertain as to what plant Columella was actually describing, since he also wrote of Aizoon, meaning eternal creature, which was a Roman reference to both Sedum and another European native, Sempervivum.  Evidently, they were both thought to ‘live eternal’ since they reproduced easily from leaves and were frequently found growing on buildings.  Columella wrote how these low growing plants were best used to cover roofs in an effort to reduce lightning strikes to homes.  The tradition of creating verdant roofs continued through time and one of the common middle-English names for such plants that was Howleke, now Houseleek; leek means plant so these roof dwellers are literally House Plants!  And here we thought that green roofs were a recent invention!  Today, Houseleek typically refers to the genus Sempervivum while Stonecrop refers to Sedum.
Naturally, with over 600 species available and habitats that range from the heat of Mexico and Honduras, (Sedum morganianum, the Burro's Tail Stonecrop) to the cold of the Russian Kamchatka Peninsula (Sedum kamtschaticum, the Russian Stonecrop), how can a gardener pick out a few favorites?  As a novice gardener, I was first drawn to the various cultivars of Sedum spurium, the Two Row Stonecrop.  Native to the cold Caucasus region of Europe, this plant only reaches 3-4” tall and can slowly spread to 24” wide.  The fleshy green leaves typically have a red margin and are oppositely arranged on the stems, with each proceeding pair of leaves set at 90º to the previous, giving the illusion that it has two rows of leaves and hence, the common name.  The leaves near the tips of the stems typically turn red with the first frosts of fall and persist throughout winter, while the lower leaves are deciduous.  During the summer, 20 or more 5-petaled star-shaped flowers appear atop 4-6” tall stems in flat-topped pedicels.  As is typical of most plants within this genus, plants need a sunny, dry location to flourish, whether it is a flower bed, a container or even as a houseplant.  The only maintenance issue is the patience needed to tease out weedy blades of grass or small weeds from between the procumbent stems!  Numerous cultivars have been introduced, including ‘Red Carpet’, which turns a luscious red come winter while ‘Dragons Blood’ and ‘Fulda Glow’, which retains red foliage throughout the year.

Sedum Sedum

Since my initial attraction to Sedum spurium, I have used a variety of different species over the years, but the two Stonecrops that truly refocused my interest on this genus was the aforementioned Sedum morganianum and a relative newcomer, Sedum rupestre ‘Angelina’.  Sedum morganianum is not hardy in NJ, but I was so captivated by the 24” long dangling stems, clothed with silver-green, jellybean shaped leaves that I could not resist making it a new garden staple.  The plant makes a superb container or houseplant and it should be placed where it is not frequently touched, as the plump leaves are easily dislodged from the stem.  Like other members of the Crassulaceae, once these dislodged leaves remain on the ground for a few days, they sprout roots, ultimately developing into a new plant!  It was initially discovered by Eric Walther, a botanist for the Golden Gate Park in San Francisco, during his travel to Veracruz Mexico in 1935.  He was in search of new species of Echeivera, but he found this plant in a small nursery and much like myself, was infatuated by the long dangling stems.  However, he did not determine the identity of the plant until it finally yielded red blossoms 3 years later at the home of Dr. Meredith Morgan in Richmond California.  Morgan was renowned for being a superb gardener and it finally became clear that this plant was indeed a Sedum!  In 1938 Eric Walther officially authored the plant and honored Morgan with the species epithet!  Interestingly, the plant was not found in the wild until February, 2008, growing on vertical cliffs near Veracruz! 
Sedum rupestre is a European native and the species epithet means ‘among rocks’.  The species sports 3” tall stems, clothed with blue, 3/8” long needle-like foliage that remain evergreen and resemble miniature spruce trees.  Angelina was found by Christian Dress of Sarastro Nursery in Austria who, while vacationing in Croatia, discovered this selection at a private garden.  In tribute, Dress honored his hostess by giving this selection her first name – Angelina!  Angelina not only has far fuller foliage than the species, it is also colored a wonderful chartreuse yellow during the warmer seasons, with tints of gold and bronze throughout the winter, as seen on the right.  Nine years ago we planted Angelina in a small pocket atop a stone wall in Rutgers Gardens.  Growing in full sun, it is never irrigated, and most of the soil has since washed away, leaving the plant simply growing ‘among rocks’ (picture above).  It is thriving!  Of course, it also makes a great groundcover or container plant as well, illustrating again that Sedums have ‘life eternal’ in a garden!