We’ll start with grafting a pear tree. We decided that after many years it wasn’t very productive for all the years and inputs we put in to it, so graft it over to another variety. This tree is on the big side of what I’d recommend doing, but it can be done on bigger trees, but it’s more effective on smaller diameter trees. The main problem with doing big trees, is that with that much wood exposed, it has a higher probability of rotting until the grafts grow enough enough to cover the wound. On a smaller tree that might only take a season or two, depending on how well the graft does, vigor of the under stock, aftercare etc. But hopefully this will get the point across so it can be applied to varying diameters of trees.
As I’ve said before, grafting is a fairly simple and straight forward process, but it can be dangerous. The knives need to be very sharp and you have to cut through the wood with a fair amount of force, and restraint, and NOT cut yourself. It’s not hard for me to imagine seriously cutting or dismembering a digit, So: SAFTY FIRST!! Always cut away from yourself and know where the knife you are in relation to each other. The following pic is how I learned and has proved safe for me and many other grafters for years.
Recommended Method of Holding Scion Wood When Cutting a Graft
Notice that I’m holding the scion with my left hand held firmly held to my chest to stabilize it, while with my right hand holds the knife and pulls to my right to make the cut, away from me into space. Having the wood stabilized makes it much easier to make a good cut(s). Always cut away from yourself, whatever cutting you may be doing (kitchen knives, chisels, saws etc.), a rule to live by! I recommend gathering a pile of prunings (scion wood) and taking some time to practice making the cuts, over and over until you can make a fairly smooth flat cut and feel comfortable with it, like anything it does take practice. It’s too easy to make a faceted, not flat cut, which won’t work as well if at all, then a nice flat, smooth cut. Best if you can make the finish cut in one smooth motion. (It may take a few swipes to achieve the final cut)
On to the grafting: First you need to make the saw cuts and clean up the prunings, I recommend a fresh saw cut before proceeding . If you’re doing big tree, you can cut it down well before you graft, but leave the intended limb long and cut to the desired spot just before beginning to graft. Look for as smooth and straight a section to facilitate the process.
1. Cutting the Under Stock, Notice the Bark Slipping From the Wood
This graft is called a Bark Graft, you need to wait until the bark is ‘slipping’, this is when the bark easily peels away from the wood, usually late March to early April here (North Central Washington State, USA). Make two vertical cuts through the bark about the width of the scion wood you are using, if the bark is slipping it’ll peel right off the wood. With bark this thick and somewhat crusty it takes a bit of force to get through it. This cut is made with the bark knife, made from a Old Hickory type kitchen knife that has all but about 2 to 2 1/2″ cut off of it (check out the image in my previous post). I put scions about 3″ apart around the circumference of the tree, this helps to bring the callous around to begin the closing up of the wound.
First Cut on the Scion Wood, This Goes Against the Tree
Back Cut , This Side Goes Against the Bark
Side View of the Scion, Wedge Shaped
The above photos show how the scion looks after it’s cut, ready to be inserted into the cuts on the tree, or under-stock. As I mentioned earlier, you want a nice smooth, flat cut to achieve as much contact between the scion and tree as possible.
The Scion Inserted Under the Bark
Scions all Inserted
The above pics show the scions inserted and ready to wrap and paint. Notice the small ‘half moon’ portion of the scion cuts sticking just above the surface of the wood.
The Graft Wrapped…
To finish, the grafts need to be wrapped to secure them and hold them tight to the tree. Make sure there are no gaps in the taping and that it goes a bit below where the cuts start, to insure it won’t dry out. Then the paint, apply liberally around the scions and across the top of the tree, on a bigger tree we usually leave a unpainted spot in the middle in case it gets hot early and sap begins to flow, it gives it a place to escape. Push the paint down into the cuts and goop it a bit around scions. This paint works best in warm weather, it dries fast and smooth and elastic. In colder temps it can get a bit chalky. When ever you put it on, I recommend coming back in a day and re-apply to cover any cracks which may and likely will develop. Also, cap the scions with a dab of paint, but don’t cover the scions with paint, they’ll won’t breath and it ends up rotting them.
In a Couple of Weeks the Buds Will Begin to Push
They will begin to show some action in a couple of weeks. Depending on how fast they grow, in late spring to early summer aftercare is important, to secure the the new, tender growth so the wind doesn’t blow them out. I’ll post more on that later.