Cuttings: New Plants From Old
Cuttings are an ever-so slightly magical part of gardening. What could be more wondrous than cutting off a small piece of a plant as big as a tree, propping it in some compost and watching a whole new plant develop? There is, of course, no magic, just a simple scientific process, but that never stops it feeling special.
Taking cuttings belongs to a group of techniques known as vegetative propagation, along with division and more advanced techniques such as budding, grafting and micro-propagation. A cutting is genetically identical to its parent plant and this allows a desirable trait to be multiplied again and again.
The most famous example of vegetatively propagated plants is surely the Hass Avocado a cultivar grown from seed. Grown now across the globe, and is essentially just one seedling grown by Rudolph Hass in 1962 which is now grown by grafting, so that any new plants are just copies from the ideal mother tree. Owing to its taste, size, shelf-life, high growing yield and in some areas, year-round harvesting, the Hass cultivar is the most commercially popular avocado worldwide.
While this creates a wonderfully uniform product that tastes the same wherever you go and is easy to pack, what happens if a new avocado disease appears that solely targets the Hass Avocado. Which plants will be different enough to develop some resistance?
Compare the technique of taking cutting with that of raising a new plant from seed. Here, the plant's DNA is allowed to express itself and genetic variety creeps in, so that a plant raised from seed has every chance of being distinctly different to its parent, also known as plant diversity or seedling variation.
So why does the humble gardener take cuttings? To provide an insurance policy against winter cold killing tender, experimental plants, speed up fruiting, to regenerate old trees and shrubs that are no longer growing successfully and to multiply desirable plants for free.