Speaker Review – Excerpted from the Winter Issue AGCBC Bulletin. For more info see Alpine Garden Club of BC.
Howard Wills – AGCBC – December 9th, 2015
Report by Jo Turner, photos by Howard Wills
Attendees of the December meeting had the distinct pleasure of hearing UK plantsman Howard Wills talk on Semperivums and Related Plants. Mr. Wills is a long-time expert grower of Sempervivums and Jovibarba. Howard runs Fernwood Nursery, in Peters Marland, near Torrington, Dorset, UK. He holds the NCCPG collections of Sempervivum, Jovibarba and has also held the Phormium collection until not long ago.
The genus Jovibarba is closely related to Sempervivum, and, as Howard noted, some experts say they are too similar to warrant a separate genus designation. The main differences are displayed in the floral structures. While the flowers of Sempervivumsare open, Jovibarba flowers are cupped, and have fewer petals, joined at the base. Unlike Semperivum flowers, which are most commonly found in shades of red, pink or purple (some species are yellow or white as well), often with a dark stripe in the center, Jovibarba flowers are usually yellow, though they can range from almost white to a deeper yellow shade.
Howard has participated in many of Britain’s most prestigious garden shows, and won Gold medals at Chelsea in 2005, 2006 and 2010. Howard, with his wife, Sally, wrote a book, ‘An Introduction to Sempervivum and Jovibarba: Species and Cultivars’, which he had a few copies of for purchase. It is chock full of information about all aspects of growing and displaying these plants. I would highly recommend it.
Mr. Wills’ enthusiasm for the genus he has specialized in for many years is infectious. Throughout his talk, his passion for all aspects of this genus shined. Over the course of the evening he shared tips on their cultivation and propagation, a variety of cultivars, history, including medicinal uses, how they relate to Fibonacci series, and how to display them to best advantage, along with a mass of stellar photos illustrating his points.
Sempervivums (common name houseleeks), are members of the Crassulaceae family, and have been grown in the UK for centuries, although (strangely), there are no species native to Great Britain. Native to higher elevations, in Morocco and Central Europe, across the Balkans, Caucasus and Iran, they are found nowhere else in the world. Howard stressed that although Sempervivums have succulent leaves similar to many more similar genuses, they are much hardier than most. Subsequently they are not nearly as tender as Echiverias, Agaves, Aeoniums and other succulent plants. He noted that Sempervivums are actually very tough and relatively easy to grow, with their only essential requirements being sun and good drainage. Snow and cold seem to not present any lasting problems either. Regarding possible predators, Howard displayed his love of wildlife when he mentioned that should blackbirds occasionally dig up his plants (often looking for vine weevils), he will check the roots, remove any larvae he finds, replant and leave the larvae nearby for a tasty meal for the birds.
Sempervivums reproduce mainly by producing offsets, the proverbial ‘chicks’ when we see a clump of hens and chicks. He noted that to encourage even more offshoots you may remove the monocarpic flowers, which usually appear in the second or third year of a plant’s life. A cautionary tip he passed along is that, as Sempervivums do die after flowering (being monocots), one might not want to purchase one in flower, although, with the presence of offsets on many plants, only the actual flowering portion would be affected. Regarding the leafy offshoots, a new set of babies should appear each year, on the periphery of the original plant. He illustrated with a photo how you can easily distinguish each year’s new stolons, which are easily removed and potted up. If new plants are desired, late summer is the best time to make cuttings. Of course one can also just let the clumps get bigger and bigger, filling a pot or area in aplanting, which happens quite quickly. Howard stressed that growing from seed is also very easily done, although cultivars won’t come true, and so aren’t usually propagated that way.
Having entered Sempervivums in many garden shows over the years, Howard really knows how best to arrange a planting for maximum interest. He shared his enthusiasm for creating patterns with red/green rosettes, geometric arrangements, tighter/looser textures, and a variety of designs with us, in a series of stellar photos. He also told us about his fascination with the mathematical repetitions created by the spirals and rosettes of these genera, and made reference to their affinity with Fibonacci spirals. The Fibonacci spiral is described as the ‘Golden Mean’ and describes a pattern made when certain numbers are repeated in sequence. Here is a link showing some Fibonacci spirals in nature: http://www.goldennumber.net/spirals. The Fibonacci sequence is where each number is the sum of the previous two numbers.
The Fibonacci spiral: an approximation of the golden spiral created by drawing circular arcs connecting the opposite corners of squares in the Fibonacci tiling; this one uses squares of sizes 1, 1, 2, 3, 5, 8, 13, 21, and 34. All in all, a fascinating and highly informative presentation by a man whose enthusiasm for Sempervivums is definitely contagious…
‘An Introduction to Sempervivum and Jovibarba: Species and Cultivars’ by Howard and Sally Wills. Published 2004. IBBN 0-9547533-0-5.
The nursery and garden are open by appointment. Fernwood offers a full mail-order service.