I thought it would be a good idea to start the New Year by giving you a behind the scenes look at one of our local wholesale nurseries that produces many of the clematis that you buy at your garden centre – the idea being that you would gain an appreciation for the often unheralded work that goes into providing good quality plant stock.
Ken Staedtler began his wholesale perennial nursery in 1989 after being encouraged to get into business by his former employer, Noel Muldoon of Muldoon Greenhouses Ltd.
Armed with a biochemistry degree in science and an intuition that tissue culture was a technology for the future, Ken opened his own cloning facility 10 years later, in 1999.
His current lab technician, Luina Rivera, emigrated from Panama with her husband Jose in 2000, and got her start cleaning up around the lab.
At Ken’s request, she learned the cloning process through on the job experience and eventually worked her way into the position by “using my common sense and working hard”. This lab currently produces 15 cultivars of clematis, as well as specialty plants such as corydalis, gentiana, cordyline, phormium and lamprocapnos (dicentra) spectabilis ‘Gold Heart’.
Clematis is a complicated genus of over 200 species, including climbers and groundcovers. For the most part gardeners seem to prefer the large-flowered hybrids, some of which have been with us for over a century, including ‘Nelly Moser’ (1897) and ‘Star of India’ (1867).
There are three basic pruning groups: those that bloom on the previous season’s growth (Group A); varieties that flower on both the previous season’s growth and new wood (Group B); and those that bloom on the current year’s growth only (Group C). Clematis are long-lived plants and prefer rich (add compost or well-rotted manure) well-drained soils with shaded roots and part (around four hours) to full sun for the crown. Adequate support (trellis, obelisk) for the vines is also critical, as the stems are quite brittle and prone to breakage.
To produce these baby vines, work is performed in a sterile Laminar Flow Station and once indoors, the plants are kept at a constant 18 C temperature and given 18 hours of fluorescent light a day. There are five distinct steps required to create a Clematis clone.
Step 1: A healthy outdoor clematis specimen is chosen and 1.3 cm long node cuttings of new growth are taken – these are sterilized (with bleach and alcohol) and placed in test tubes with Agar for 1 month. Those with bacterial growth during that period are discarded.
Step 2: The clean cuttings or ‘mother plants’ are then transferred to sterile baby food jars for the multiplication stage. Cuttings are kept in Agar with tailored vitamins and micronutrients (each clematis cultivar has its own nutrient recipe) for two to six weeks, creating several new shoots (two to five) from the base.
Step 3: These shoots are separated and put into another sterile baby food jar for the rooting stage. Seven to ten plants per jar are left in agar (with root hormones and macronutrients) for six to seven weeks, during which time they root.
Step 4: The rooted plants are then rinsed with water and separated, after which they are planted in trays with a sterile soil media.
Step 5: Once they have gained some size, they are potted into nine centimetre containers, allowed to root-in and then sold as liners to other growers or plant brokers. Depending on the Clematis, the whole process can take up to a year.
Mike Lascelle is a local nursery manager and gardening author (email@example.com).