   New Plants from Stem Cuttings - April 9, 2008 Jeff Schalau, Associate Agent, Agriculture & Natural Resources, Arizona Cooperative Extension, Yavapai County Most gardeners have been given a plant shoot by a friend and rooted it to produce a new plant. The scientific term for this process is "asexual propagation". Asexual propagation includes growing plants using cuttings, layering, plant division, budding, grafting, and tissue culture. Each plant derived as a result of asexual means is genetically identical (a clone) to its mother plant. It should have the same leaf shape, flower color, fruit characteristics, growth form, vigor, and so on, as the parent plant from which it was grown. Most indoor plants are easily rooted in plain water and cacti and succulents in well-drained mineral soil. Woody plants can be more difficult to propagate. Depending on the species, you may have to research the timing and concentration of rooting compound to increase your chances of success. The four main types of stem cuttings are herbaceous, softwood, semi-hardwood, and hardwood. Leaf and root cuttings can also be used. These terms reflect the growth stage of the stock plant, which is one of the most important factors influencing whether or not cuttings will root. For practical purposes, let’s review some of the practices that will increase your success in rooting cuttings. Always take cuttings with a sharp blade to reduce injury to the parent plant. Dip the cutting tool in rubbing alcohol to prevent transmitting diseases from infected plant parts to healthy ones. Remove flowers and flower buds from cuttings to allow the cutting to use its energy and stored carbohydrates for root and shoot formation rather than fruit and seed production. To obtain more uniform rooting, you should consider using a rooting compound containing indole butyric acid (IBA) or naphthalene acetic acid (NAA). Prevent possible contamination of the entire supply of rooting hormone by putting some in a separate container for dipping cuttings. A small of rooting compound container lasts a long time. The brand makes little difference and instructions for use are included on the container. Select cuttings from vigorous, healthy wood, preferably from the upper part of the plant. Avoid excessively vigorous shoots as well as weak, spindly growth. Once cuttings are made, they must be placed into a growth medium such as coarse sand, vermiculite, soil, water, or a mixture of peat and perlite. It is important to choose the correct rooting medium to get optimum rooting in the shortest time. In general, the rooting medium should be sterile, have little or no nitrogen fertilizer, drain well enough to provide oxygen, and retain enough moisture to prevent water stress. Moisten the medium before inserting cuttings, and keep it evenly moist while cuttings are rooting and forming new shoots. Some plants root better in warm soil. Commercial operations often do this by heating the propagation beds.Tip cuttings are also commonly used in production nurseries. Here, a 2 to 6-inch piece of stem, including the terminal bud is cut off the mother plant just below a node. Remove lower leaves that would touch or be below the rooting medium. Dip the stem in rooting hormone. Gently tap the end of the cutting to remove excess hormone. Insert the cutting deeply enough into the media to support itself. At least one node must be below the surface. Commercial producers propagate cuttings in greenhouses, but you can simply put a thin plastic bag over the top of the pot to increase the humidity and place it in a bright location indoors. Once rooted, plant the cutting in a clean pot preferably filled with sterile potting soil. Grow rooted outdoor plants outdoors and indoor plants in a bright spot inside your house. Start with easy-to-root plants such as figs or grapes, then advance to more difficult species. There are many excellent resources available on this topic. Libraries usually have several books on plant propagation and the Internet is also a good source of information. Below are some links to useful plant propagation web sites. Have fun and share your plants with friends. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at cottonwoodmg@yahoo.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. More Information on Propagation from Cuttings Propagation of Woody Ornamentals by Cuttings (University of Florida) http://edis.ifas.ufl.edu/EP030 Propagating Deciduous and Evergreen Shrubs, Trees, and Vines with Stem Cuttings (Washington State University) http://cru.cahe.wsu.edu/CEPublications/pnw0152/pnw0152.html Plant Propagation by Stem Cuttings: Instructions for the Home Gardener (North Carolina State University) http://www.ces.ncsu.edu/depts/hort/hil/hil-8702.html |