A great question came in this week about propagating blueberries! First, what is propagation? The North Carolina Extension Gardener Handbook defines propagation as the process of producing a new plant from an existing plant. Propagation can be broken down into two general types; sexual and asexual propagation. Sexual propagation is pretty simple, being reproduction through seeds. Two parents combine through pollination and fertilization to create offspring that is different from the parents. Asexual propagation, sometimes called vegetative propagation, uses plant parts from the parent plant to clone that plant. This can be accomplished by using stems, roots, and/or leaves to create new plants.
In the case of blueberries, and generally all fruit, we want to use asexual or vegetative propagation. The reason for this is that we want to clone the parent plant so that the new plant is “true to type”. This means that we are certain the offspring is the same as the parent plant.
When my youngest daughter was about four years old, she loved to eat apples (she still does). She always saved the seeds and wanted to plant them so she could grow apples in our backyard. While this is a great idea, it is not a very practical one. If we were to propagate those seeds, it would take 15 to 20 years for us to have apples! This is because the wood has to mature before it can produce fruit. The other problem is that we would have to wait that long to see what kind of apples we would be producing. You see, the fruit is determined by the cultivar but the seed is determined by both parents. Let’s say for example that we had a Granny Smith apple tree that was pollinated by a crab apple tree. The fruit would look and taste like a Granny Smith. But, what do you suppose the seed would make? I would like to think we could call that a Crabby Granny! All joking aside, we would have no idea how the fruit would look or taste because that would be determined by the cross of the parents.
The same can be said for blueberries. So how would we propagate them? Vegetative propagation of blueberries can happen in three different ways, semi-hardwood cuttings, hardwood cuttings, or through division. Semi-hardwood cuttings are the most used to propagate blueberries. Cuttings are taken from semi-hard new growth and then stuck in a growing media consisting of aged pine bark fines and sand. Semi-hardwood is the stage of new growth that is soft enough to bend without breaking. If the wood is too mature, it will break and if the wood is too succulent, it will break. So, like Goldilocks, we want it right in the middle. This type of cutting is usually taken somewhere around August 1st in our area of Eastern North Carolina.
