Cherries belong to the genus Prunus, which also includes peaches, apricots, plums, and almonds; Prunus, in turn, is part of the very economically important family Rosaceae, which includes roses, blackberries, raspberries, strawberries, apples, pears, and other important horticultural crops (Wikipedia, 2015). The two most important species of cherries are Prunus cerasus, the sour cherry, and Prunus avium, the sweet cherry. Both types of cherry probably originated in Western Asia and spread throughout Europe prior to historical records; both species are now grown worldwide (Rieger, 2012).
Many sweet cherry varieties are self-incompatible, meaning that they cannot pollinate their own kind (Hartmann et al, 2011); this includes very popular sweet cherry varieties like Bing, Lambert, and Napoleon (Gaus and Larsen, 2009). In order to pollinate these varieties to allow fruit to set, growers must place “pollinizers” of a different variety at regular intervals within blocks of the self-unfruitful varieties. Sour cherry varieties are self-fruitful and will pollinate themselves without the intervention of different varieties (Rieger, 2012). Because of sweet cherries’ tendency toward self-unfruitfulness, which results in greater genetic variability, the seeds of sweet cherries, while important in professional breeding and rootstock operations (Hartmann et al, 2011), are not a good choice for home propagation. Other propagation methods will preserve the desirable characteristics of the trees.
Propagation from cuttings may be attempted with cherries and other fruit trees with some success, but the success rate is a bit low for most home gardeners; propagation of cherry trees from cuttings is most often used by nurseries for cloning of rootstock. Micropropagation techniques for cherry and other Prunus spp. have been developed and are used commercially, mostly in Europe (Hartmann et al, 2011). Regular visitors to this website will recall last week’s attempt to micropropagate orchids at home and realize that it is not for the casual home gardener. Micropropagation certainly has its benefits—viruses, for example, can be eliminated from clones through micropropagation techniques—but the requirements for sanitation and controlled conditions place it outside the comfort level of all but the most intrepid home gardeners.
Grafting is the most reliable and cost-effective way that you can propagate cherry trees at home, and it is the way that most commercial cherry trees in the United States are produced (Hartmann et al, 2011). There are several ways that you can graft cherry trees, but each involves the same basic principle: A portion of a cultivar that you want, called a scion, is attached to the lower part of another, usually young, plant, called the rootstock. The scion will become the upper part of the mature plant (the trunk, branches, leaves, etc.) and the rootstock will become the root system. This is often accomplished by physically joining the stems of the scion and rootstock; the junction is then wrapped up and, if the graft is successful, the two plants grow together.
The technique most often used with cherries, and the one we will talk about now, is a specialized type of grafting called budding, and specifically chip budding. Chip budding has become the predominant method of propagating fruit trees and many other trees and shrubs in temperate climates. Chip budding can be performed on both dormant and active rootstock, making it perhaps the most flexible form of grafting (Hartmann et al, 2011).
HOW TO DO A CHIP AND BUD GRAFT ON A CHERRY TREE
You will have the best chance of success if you use a young rootstock and scion—between one half and one inch in diameter is best (Hartmann, 2011). Also, your rootstock and scion should be about the same diameter, because the cambium, the thin green layer beneath the bark, of the two pieces need to make contact in order to have a successful graft (WikiHow, 2015).
Also, you will need a sharp knife (there are specially designed grafting knives, but any straight, sharp knife will do), some grafting rubbers (a.k.a. rubber bands), and some tape to wrap the graft (Parafilm is best but may be tough to acquire—you can use white medical tape, Scotch tape, duct tape, whatever it takes to seal the graft union).
OK, here we go:
Step 1. Get your scion and rootstock. Select a branch of the cultivar you want to graft; look for one with plenty of healthy looking, but not opening, buds. You can certainly get away with cutting a short piece of branch, but if you cut one a foot or two long, you will have more room to make mistakes. Make sure you remember which side of the branch was closer to the roots when it was on the tree, because it will be important later. Your rootstock should be a healthy, vigorous plant, since it will be providing all of the energy to keep the scion alive.
Step 2. Cut the grafting site on the rootstock. Choose a straight section of the rootstock not too close to any nodes. With your knife, carefully but deliberately cut down (toward the roots) into the stem at a 45 degree angle. Next, make a shallow cut from about an inch above the first one, angling down to meet the first cut. The notch you end up with should look like this:
Step 3. Cut the bud from the scion. You want to cut a piece from your scion that includes a bud and is the same size and shape as the piece you just cut from the rootstock. Start just below the bud and cut down (you do remember which way it went, right?) at 45 degrees, and then make your shallow cut about an inch higher, or however far you need to make this piece the same size as the grafting site you cut into the rootstock. You should now have a bud and a space to fit it, like so:
Step 4. Wrap that rascal. Use the grafting rubbers to bind the bud tightly onto the rootstock. After you have secured it, wrap the whole graft area with tape. You can wrap most of the area with multiple layers, but don’t put more than one layer of tape over the bud itself. Congratulations! You have performed a chip and bud graft.
Step 5. Remove the wrapping. After about a month, take the tape and rubber off and see how the bud looks. If it’s healthy looking, great, you succeeded. If not, you can always try again. If the graft has been successful, the next spring you can cut the tree above the graft area, and it will grow from the bud that you grafted (Hartmann et al, 2011; WikiHow, 2015). Nice work!
Gaus, A., and H. Larsen. “Pollination of Tree Fruits.” Colorado State University Extension (2009).
Hartmann, Hudson T., Dale E. Kester, Fred T. Davies, Jr., and Robert L. Geneve. Hartmann & Kester’s Plant Propagation: Principles and Practices (8th ed.). Upper Saddle River, NJ: Pearson Education, 2011.
Rieger, Mark. “Cherry – Prunus avium, Prunus cerasus.” Mark’s Fruit Crops (2012).
WikiHow contributors. “How to Graft a Tree.” WikiHow (2015).
Wikipedia contributors. “Rosaceae.” Wikipedia, the Free Encyclopedia (2015).