Not all great plants make their way to garden centers for a variety of reasons. One significant reason that prevents some beautiful specimens from entering the mainstream is difficulty in propagating and producing them in enough numbers.
There are many evergreen magnolias from Asia that have proven very difficult to produce in any way other than seed. Seed production for trees can be impractical in most cases for many nurseries for a variety of reasons. At the JC Raulston Arboretum, we’ve been growing one species which we think is quite outstanding – Magnolia yuyuanensis or Chinese wood-lotus. It bears pure white cupped flowers with deep red stamens in spring followed by pinkish-red seed pods and all backed by narrow, glossy, evergreen foliage. Our plants have survived temperatures as low as -19C (-3F) for short periods and have had no issues with temperatures in the low teens.
The propagator at Atlanta Botanical Garden, Ethan Guthrie, has been using very high rates of rooting hormone (50,000ppm KIBA or potassium salt of indolebutyric acid). Typical commercial concentrates of KIBA top out at 10,000ppm KIBA so Ethan’s rates are through the roof but you can’t argue with his success.
An NC State Horticultural Science graduate student, Dominic Gillooly, is now working with Dr. Tom Ranney to get a handle on propagating M. yuyuanensis and other evergreen species. He’ll be trying rooting hormone rates of between 10,000ppm to 50,000ppm with a control of 0ppm on these magnolias to try to develop a commercially feasible propagation regime for these outstanding plants.
Graduate student Dominic Gillooly collecting a couple hundred cuttings of Magnolia yuyuanensis for a research project.
Knowing how difficult producing this plant from cuttings has proven to be we planted a hedge of them years ago with plans to coppice or cut them back regularly to produce good cutting wood for research on the best propagation methods. We love it when our plans and our faculty and student’s needs coincide. If Dominic and Tom can produce some good results, we’ll be sure to get these great magnolias and the knowledge of how to produce them into the hands of NC nurserymen fulfilling J.C.’s exhortation to “Plan – and Plant for a Better World.”
Follow me at @jcramark because life is too short for boring plants.
Check out all the happenings, see more images, and learn more at the JC Raulston Arboretum where we are Planting a Better World.
JC Raulston Arboretum 