We had another relatively mild day with temperatures well about freezing. Big John and Larry continued work on the continued take down of the Holiday Light Show (HLS). Marv B. later helped out with this process. Ron P. continued repairing lights and both Alan and Ron R. headed out to start cutting back some of our ornamental grasses. Alan also swept and helped with the HLS. The cooler season grasses may start actively growing in March if we get more warm weather which makes this cutting vital right now. We still have plenty of tidying to accomplish out in the gardens and I want everything looking nice for our March 19th Spring Symposium (Plantaholics Retreat). We still have plenty of room at this event which should be a blast. See information on the program and registration details at www.rotarybotanicalgardens.org. Vern, Dave and Jim continued on some carpentry projects and Dr. Gredler continues to be our main painter and had plenty of work today. Dick H. was working on some of our mowers and Kathy came in to help out with some office work. Gary continued making plant labels for some of our spring orders. Bill O. came in later to help wrap up cords from the HLS We also saw Rollie and many others today.
I think we’ve grown cardoon (Cynara cardunculus) every year at RBG as an annual (hardy to zone 7). In short, I love the rugged, silvery contribution out in the garden from this plant. The imposing architecture of this plant is impressive and silver can be excellent in the garden (see cardoon with “backlighting” above). Native to portions of the Mediterranean and Europe, this member of the sunflower family has a long history of cultivation as an ornamental plant and an edible. The celery-like stalks may be harvested, blanched, steamed or braised…then eaten. Blanching (excluding sunlight) tenderizes and improves stalk flavor. Introduced to North America in the mid 1800s, this plant will get 4′ tall and 4′ wide during our warm growing season (larger in warmer climates). This plant is considered invasive in California and has naturalized in other warmer climates. The close cousin to cardoon is the artichoke which has a similar look but is used in a different fashion. We plant cardoon in full sun in nice soils. Providing ample watering and continuing to remove the oldest leaves on the outside of the plant as they arch downwards makes for a happy plant. We have seen some mildew problems on occasion and unfortunately, aphids seem to enjoy them as well and can be found in profusion on the underside of the leaves. Slug damage is occasional too. Regardless, the strong architectural contribution of this silver plant is excellent in the garden and the “real estate” dedicated to cardoons brings back a strong “visual return”!
Cynara cardunculus at Olbrich Botanical Gardens (Madison, WI) above and below
nice use of Cynara cardunculus at Allen Centennial Gardens (UW-Madison) above
showy blooms of cardoon (above and below) – they necessarily bloom each year though…
light frost on cardoon (above)
cardoon and bronze fennel (above)
‘Porto Spineless’ cardoon (Cynara cardunculus) above and below
Mark Dwyer, Director of Horticulture, Rotary Botanical Gardens
I am the Director of Horticulture at Rotary Gardens (Janesville, WI). Along with a talented grounds staff and dedicated volunteers, I enjoy being involved with this wonderful botanical resource. My educational background is in landscape architecture and urban forestry but it didn't take long to become a plant enthusiast and find a lifelong career.