I'm member of a small Vancouver conservation group "Free the Fern" working to remove invasive plants like ivy, yellow-archangel, and Himalayan blackberry along the greenbelt walkways in Champlain Heights and return them to a more natural and healthy state. We have a plant order coming this fall, but financial resources for buying native plants are limited, so it would be great if we could augment our stock by doing some propagation on our own. From what I've read it sounds like we should still be able to take softwood cuttings in the next couple of weeks, and we are also wondering about trying ground layering for plants with low branches like Ocean Spray. Plants we are thinking of trying now from softwood cuttings are: Pacific Ninebark, Red-flowering Currant, Thimbleberry, Twinberry Honeysuckle, Orange Honeysuckle, and maybe Dull Oregon Grape. Without a greenhouse system for misting and watering we realize that our success may be limited, but we'd like to give it a try. Any advice to improve our chances would be appreciated. Some initial questions are: Rooting 3 or 4 cuttings in a single 1 gallon pot, seems more manageable than keeping a lot of small pots from drying out - does this make sense? Does they type of rooting stimulant matter? one has .1% IBA and "Mycoactive Technology", another has .05% IBA plus 0.025% NAA For soil medium should we use a sterile mix of peat/sand or vermiculite/sand or should we incorporate compost as well? Should the sand be 'concrete sand' or 'river sand' or ? I assume they should be kept in the shade until rooted. Should we put a plastic bag over the pot to keep the humidity up? Should we also try some hardwood cuttings later in the year, or are they too difficult for beginners? Are perennials like Sweet Ciceley and Large-leaved Avens worth trying from seed? Any other plants we should try?
Not my area of expertise, but the first thing I would do is pick up a copy of "Propagation of Pacific Northwest Native Plants" by Robin Rose et al., published by Oregon University Press. I'm fairly certain that rooting stimulants will be somewhat specific to species -- I know from our plant records that one can sometimes see the trials with different ones. Plastic bags over plants usually equals fungal issues...
Pacific ninebark is super easy to grow from cuttings. I've had 100% success doing so. You can put several stems in a pot, or just one. I cut them to around twelve inches, about the thickness of a metal coat hanger in winter when I prune mine back, stick them in the soil about six inches without any rooting hormone and they start growing in the spring, developing a large root system by the end of the first year. It's a great, fast growing plant once established and are visited by insects and birds.
