There are many ways to propagate plants, but the method I want to share is asexual propagation. With this method, which does not rely on seeds, you duplicate a plant by rooting a cutting from it. For some species, it is the best way to maintain them.
Have you ever grown a plant that produced a sport, a branch that was obviously different from the mother plant? Maybe you like the sport and want to propagate it. Seeds from the mother plant probably would not yield a plant like the sport, so you need to propagate the sport from cuttings.
Many plants are easy to reproduce this way, so mastering asexual propagation can save you money. I have many landscape plants that I propagated from cuttings.
You will maximize your propagation successes if you follow these recommended procedures. Even so, some cuttings won't take, so it's a good idea to propagate more than you need.
The planting medium is extremely important. I use equal parts pumice and sharp sand. These materials are quick draining yet hold air. They also have sharp edges that prompt the roots to divide. I have re-used some of my soil mixture for years, mixing pots together when the volume diminishes. You can also use a combination of perlite, vermiculite and sand. These are soil-free mixes. Coir, compost and leaf mold can also be part of the mix; however, these materials may contain pathogens that could kill your cuttings.
I use old pots, small ice-cream containers and take-out salad containers. They need to be deep enough to allow for root growth. Be sure the containers drain well as cuttings like moisture but not floods. When you have filled your containers with your chosen planting mix, add water and observe how well it drains. When the planting mix is uniformly moist, it's time to add the cuttings.
I have had success with cuttings at all times of year, but now is ideal as plants are starting to produce new growth. Consider propagating dogwood, bottlebrush, lavender,figs, boxwood, pomegranate, willow, cotoneaster, elms, maples or junipers. I have been successful with all these plants. Pines and other plants with very hard wood are harder to propagate asexually.
Snip a 6- to 8-inch piece for your cutting. Remove all the leaves on the bottom half of the cutting, then cut the bottom at an angle to expose more surface. Be sure you can recognize the root end of the cutting. You don't want to plant the cuttings upside down. Make a hole in the potting medium with a chopstick, insert the cutting and pat to seal. Keep watered and in a cool, shady area.
Despite having no roots, the cutting will continue to transport nutrients and water from the potting medium. In time, the physiological changes begin that prompt the cutting to put out new roots.
To make sure your cuttings stay moist, you can cover them with a plastic bag or invert a jar over them. In most cases, they do better when covered. Resist tugging on the cutting to see if it has roots yet. You might break off the tiny new rootlets.
Root development does not happen overnight. It can take several weeks or even months to have rooted cuttings. You will know a cutting has rooted when the tip starts growing. Dig it up carefully—I use an old soup spoon—and plant it in regular planting mix. Water well and keep in a shaded area, gradually exposing it to sunlight.
Workshop: U. C. Master Gardeners of Napa County will sponsor a workshop on “Home Composting” on Saturday, March 24, from 9 a.m. to 10 a.m.., at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Napa. Learn the basics of composting, including tools needed, techniques and bin types. Turn your yard trimmings and kitchen scraps into rich compost to use as a soil amendment or garden mulch. Register online: www.cityofnapa.org/compost
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.