The importance of the art of grafting fruit trees was first on the list of things that Will Lewis explained at his grafting workshop on Thursday March 21st. In one simple statement he summed it up: “Most fruits that you eat are from a grafted tree.” Johnny Appleseed himself, as legend has it, was well known for sowing the seeds of apples far and wide, but perhaps this was because he understood that out of the thousand seedlings he was planting ahead of the settlers maybe one hundred would result in apples that were pleasant to eat. When fruits come from a seed there is always a possibility of cross-pollination that results in a diverse genetic structure. With this diversity comes variability and inconsistency—leaving you with apples called “spitters” that are so bitter they make you want to “spit” them out and are good for cider, but not for eating. The well-known apples we are all used to eating, gala, honey crisp, granny smith, and so on are all originally from a randomly delicious fruiting tree that was named and grafted.
Luckily, we already have many delicious apples readily available, whether they are wild trees or cloned varieties, and can graft from existing trees. If we want to stand on the shoulders of Johnny Appleseed, the first step is to choose our scion wood and rootstock. Scion wood determines taste so that choice is easy: choose an apple you like to eat. Rootstock on the other hand, is what determines the size, height, disease resistance, density of fruit, years to fruit, and lifespan of your tree. Many are partial to dwarf rootstock for instance, because although the trees have a shorter lifespan and are less resilient, they fruit earlier so you get an earlier return on your investment and they require less work to cultivate and harvest. While scion wood can be easily harvested from a tree of your choice, the multiple factors involved in choosing root stock makes it worth getting from a reputable nursery supply so you can be sure of what characteristics you will be getting.
Once these choices have been made, it’s time to talk process. Although there are multiple methods of grafting, the workshop focused on the whip and tongue union. This method mechanically binds the scion woods to the rootstock, and the only tools you need are an exceedingly sharp knife (ideally flat on one side and beveled on the other), some wax (toilet bowl wax will do), some wet newspaper or peatmoss, and grafting tape (or flagging tape in a pinch). And of course a wealth of knowledge from a practiced horticulturalist and the company of other eager grafters-in-the-making helps.
The first step is to match your scion wood to a rootstock of a similar circumference. You then clip a section off the top of the rootstock right below a bud, exposing the cambium (a light green ring just beneath the bark that acts as the thoroughfare for nutrients and water). Using your knife, you cut that fresh end into a diagonal slice to increase the surface area of the cambium and increase the chances of your “union;” the more angled the slice, the greater the cambium contact between scion and rootstock. It’s important that the cut be one flat unified stroke to avoid gaps between the cambiums.
You then make a matching sloped cut at the tip of the scion wood, making sure that you have your buds facing upwards. The next cut you make is directly into your freshly cut ends, to create a little notch where you will fit the two together. With each piece prepped, you merge the two notches. If you have more than three buds above the graft you have one final cut to make: cut horizontally above the third bud, because an excess of buds requires too much in the way of water and nutrient support and will take energy away from a successful union.
Once you’ve achieved a satisfactory union, you wrap the point of contact with flagging tape to encourage the merger. You then coat the tape and the tip of the scion wood in wax as well. This step is particularly important because this seal is what keeps moisture in your scion wood, and if the scion dries out, you won’t get a callous to form joining your graft.
Having made your graft, it’s important to place your rootstock in a ball of wet newspaper or paper towel, or in a bag of peat moss for storage. A good storage place will keep your fresh graft at about fifty or sixty degrees as you wait for your callous to form (for peaches and apricots this increases to seventy five degrees). This process should only take about one week. If done well, this method has a success rate of 80 to 90 percent. The question of storage, of course, brings up the question of timing. You want to harvest your scion wood in February, your rootstock in February or March in West Virginia, and more generally in late winter/early spring depending on climate, weather, and location. If you find yourself ahead of schedule and with scion wood but no rootstock, your scion cutting can last a few months in the fridge.
After you have a formed callous and successful graft, and if your ground has thawed it’s time to plant! It’s important to start with a well-tilled bed and to water attentively as your tree could be in a nursery bed for up to a year. If you are feeling ambitious and planting multiple trees, plant them 16-24 inches apart in the nursery. If buds begin to grow while the plant is in the dark, it is worthwhile to harden off the plant in indirect sunlight before planting.
Speaking of ambitious grafting, now that you know of one way in the art of grafting, you can explore and get creative. Grafting two varieties on one tree for example, is a great way to address the issue of having a singular plum or cherry tree, as both require the cross pollination of a different variety of tree to bear fruit. Henry Lang in New Hampshire even grafted around 230 different varieties to one tree in an attempt to push the boundaries of how much diversity you can achieve with just one tree with grafting.
If this blog has peaked your interest and you want more information, for anything from how to manage your young trees after their first year, to other methods of grafting, these two books come highly recommended by our very own Will Lewis: The Holistic Orchard by Michael Phillips and The Apple Grower by Michael Phillips. Happy Grafting!