Horticulturalists use cuttings instead of seeds to propagate plants with desirable traits, select only male or female plants, speed up the time to maturation, or because plants grown from seed are either weaker or different than the parent plant.
Cuttings allow both commercial and private growers to have greater control over the genetic make-up of the new plant. Seeds from apples for instance may have been pollinated by non-edible strains (i.e., crabapples) and produce bitter fruit.
Advantages of Cuttings
Cuttings enable propagating plants with desired traits that are free from disease or disease resistant and mature faster than plants grown from seeds. Some plants, such as olive trees, reproduce more successfully vegetatively (from buds or cuttings), and propagating deciduous species allows selection of the sex. Once a suitable mother plant has been selected, an endless supply of clones (from cuttings) can be produced.
Disadvantages of Growing Plants from Cuttings
Plants grown from cuttings are genetically identical to their parent. They possess both the strengths and weaknesses of the original plant. As such, if the parent is particularly susceptible to a disease or environmental condition, all of the clones will be also. If an entire forest or crop is planted in this way, this lack of genetic diversity may expose it to mass die-off or reduced productivity, if faced by these stressors.
How Cuttings Work
Cuttings are a form of asexual (without pollination) vegetative reproduction. A stem or branch of a mature tree is cut and then either planted directly in the soil or in a rooting mixture to promote root formation. Auxins are plant hormones often used to promote new root formation. Once new roots have formed, the plant is then transplanted into its final home.
Commercial applications of cuttings
Potatoes, apples, olives and other commercial tree species are all propagated by cuttings. Potato leaf bud cutting obtains clonal cultivars quickly for seed certification and breeding programs. Apple trees bred for sweetness and appearance are also cloned to maintain desirable traits. As apple growers often pollinate their trees with non-edible strains (i.e., crabapples), growing apples from seeds is laborious and unproductive.Trees used in forestry can take 15 to 20 years between generations, making the economic value of cloning desirable trees very compelling.
Using Cuttings in the Garden
Cuttings are a fast and easy way for the home gardener to propagate desirable plants. Many herbs (mint, oregano) are more flavourful when grown from cuttings, and flowers can often be rooted in a jar of water with or without one or two drops of growth hormone. You can also propagate favourite tomato plants by cutting or layering, where a stem is lain horizontally in the soil to encourage new root formation.