By LMG Calla Victoria
At my last Louisiana Master Gardener General Meeting we viewed a fascinating PowerPoint presentation on propagation. The process of creating new plants from an existing plant is called propagation, and that is how the majority of the plants in the world today exist. There are two types of propagation processes, both of which come from a mother plant. Plants can be propagated by sexual and asexual propagation.
Sexual Propagation: Seed formation takes place only after pollination. Once fertilization has happened, seeds are formed. We can either harvest seeds from the blooms of plants or from seed sacks that develop on your existing plant material. Angels trumpets trees and jasmine plants develop seed sacks, once the seed sacks dry out you can gather the seeds and plant them. We can purchase seeds in stores, at plant sales and online. And in many cases birds carry and drop seeds that germinate and voila…you have new plant volunteers in your garden that you did not plant.
Asexual Propagation: This process is also called vegetative propagation. Stem cuttings, root cuttings, leaf cuttings, division, layering, stooling, grafting and budding are all vegetative methods of propagation.
Cloning plants from stem cuttings of an existing plant-We take cuttings of the tender new growth of plants, pull off the bottom leaves which is where auxins form, dip the ends in rooting hormone and plant in rich soil. Auxins are the hormones that stimulate root growth, so where ever you pull off a leaf, that is a place where roots will grow. When propagating from cuttings, always take several cuttings as all may not take, so plant several cuttings.
Propagating from leaf cuttings-In some cases like succulents you can just pluck off a leaf of the existing plant and pop it into some soil and it will germinate creating a new plant.
Stooling-This is a type of air layering and is one of the easiest ways to create new plant material; and the process works with most climbing plants. Basically you bend down a branch so that it makes contact with the soil, place a stone or brick on top of the branch so that it stays in contact with the soil and does not pop up. In six to eight weeks, once you remove the stone and try to lift the branch you will find that it has taken roots. After the roots are formed, the branch is cut off from the plant and the newly rooted branch then is replanted. In many cases climbing plants will do this on their own. One of my groundcover roses is always rooting itself, so I just clip off the rooted portion and plant it.
Propagating by Division-Many plant species produce offshoots after blooming. The offsets are sometimes called pups because they are little baby plants of the mother plant. Once the pup has grown to half the size of the mother plant, the offset can be removed and potted. As a rule, bromeliads set off as many pups as leaves on the mother plant, so if the mother plant has 15 leaves it will put out 15 pups. Crinum lilies (Crinum americanum L.), walking irises (Neomarica gracilis), and birds of paradise (Strelitzia reginae) also put out pups after they bloom.
Plant propagation is a very creative and lucrative field. Propagators are always looking to create more sturdy plants that are disease resistant, drought resistant, cold hardy, as well as trying to create new species of hybrid plant material. Now we have so many dwarf varieties of plants, and one of the biggest developments in recent years is the Encore azalea, which blooms several times per year and was invented by plant breeder Robert E. "Buddy" Lee of Independence, Louisiana. The evergreen Encore® Azaleas enjoy more sun than traditional azaleas and come in both regular and dwarf forms. The invention of these wonderful plants made old Buddy an instant millionaire. Knockout roses are another innovation in the plant world that has made millions. Knockout roses are disease resistant, and bloom year around. Hybridizers took all of the negatives of growing roses and got rid of them. Knockout roses never get black spot, they are upright bloomers, repeat bloomers, and take lots of abuse and neglect. New on the horticulture horizon are the “glow-in-the-dark” plants. This invention was achieved by crossing the plant material with the chemical reaction of the enzyme luciferase and a molecule call luciferin, which is what causes bioluminescent organisms like fireflies to glow. I wrote an article about the inventor of these plants about a year ago and that article can be viewed on this website.
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Remember, never get too busy to stop and enjoy the beautiful flowers!