Grafted tree care
Many ornamental cherry trees and most fruit trees sold at garden centers are grafted, and in fact, grafting is essential in many orchards to ensure high-yielding disease-resistant trees. But what does that mean?
Grafting is where the tissue of one plant is joined to another to make a single plant.
The rootstock is chosen for vigor, disease resistance, and adaptability to certain soils. A stem from the desired fruit tree called a scion is then cut and joined to the rootstock ensuring the vascular tissues align. Over time the cambium layers grow together to make a graft union.
Many fruit trees have the golden queen peach tree as rootstock and many pears have a quince as the rootstock. For ornamental trees like the cherry tree, the grafting may take place higher up in the trunk of the rootstock for aesthetic purposes. A weeping cherry is often grafted higher on the trunk to achieve the desired umbrella shape and the gardener can mow under it with ease.
The important things to watch out for in any grafted tree are reversion and suckers.
You can usually see the graft union inside the main mass of branches. It will look like a big, roundish, knobby growth. If you see straight stems growing anywhere below that knob, this is due to reversion.
Reverted stems are usually really obvious because the leaves will also look different from the rest of the tree, as will the blossoms. These branches might even bloom at a different time from the rest. The growth is usually much more vigorous than the weeping parts too because it is the rootstock.
If you catch them early, you can just cut off the reverted stems and go about your day. Cut them as close to the growth point as possible taking take to not tear the branch.
Suckers are shoots directly off the rootstock and these should be removed. A tree that is sending out a lot of suckers may have some stressors like pests, diseases, or drought as the tree prepares for the main trunk to potentially die. Do a good visual assessment if there is a lot of sucker growth to try and identify any issues.
Grafting is a fantastic way of getting the best of both worlds, with strong vigorous rootstock and the fruit we want on our trees in Auckland.