posted on May 16, 2010 14:37
Rooting cold group (Sphaerocarpium) cuttings
Written by: Michael Graupe
Sticking cuttings: Any pot with sufficient drainage holes can be used. The substrate consists of well wetted New Zealand long fiber sphagnum moss and horticultural perlite.
Place a ½ inch thick layer of sphagnum moss at the bottom of the pot. Place the cuttings evenly distributed on top so that the cut just touches the surface.
I found that using a rooting hormone powder (Rootone) did not make much of a difference. Fill in the perlite, water well, and dress the top with another thin layer of sphagnum moss.
Rooting conditions: In winter I place the pot on a heat mat set to 60F under fluorescent light (13h/day) in my unheated greenhouse. Air temperature reaches upper 60s to mid 70s during the day and drops into the 40s (rarely upper 30s) during the night. In summer no heat mat or lights are needed with temperatures from the upper 70s during the day to mid 50s at night. I spray the cuttings with water once a day in the morning and make sure the substrate is moist enough. I also remove all leaves that drop off to prevent mold growth. Once roots emerge from the drainage holes (4-8 weeks), the cuttings can get potted up.
(Copyright: 2010 Michael Graupe)
Cuttings from the Sphaerocarpium group of Brugmansia (B. sanguinea, B. arborea, B. vulcanicola and their hybrids) are often notoriously difficult to root. After a few unsuccessful attempts, watching the cuttings turn into slimy mush within a short period of time, I finally found a method which I have now used successfully even in mid winter. I also applied it to other hard to root plants such as iochromas and passionflowers from the Tacsonia section with excellent results.
Cutting preparation: Cut 5-8 inch pieces of reasonably mature growth. Cut right below a node at a slight angle, remove all large leaves and cut ~2/3 off the remaining larger leaves to reduce water evaporation. Slice off some bark just above the cut as seen in the photo. This will produce a larger callus from which the roots grow.