The weather today was overcast, cool, and damp--prefect weather for grafting. So, once the early morning showers moved off to the northeast, I spent the day grafting trees. I used two of the grafting methods I have described in the past; the
3-flap graft and the
bark graft (follow the links for details). In this post I'll be showing these grafting methods again but this time I wanted to point out a few of the tricks of the trade.
I don't try to start grafting until the leaves of the stock tree begin emerging. I also don't graft a tree until it has demonstrated a vigorous growth rate the previous growing season. The tree pictured at right put on almost 2 feet of new top growth in 2018 and is a perfect candidate to accept a 3-flap graft.
In the past, several growers has asked about the proper height for making a graft. On small trees I always try to place the graft at a comfortable height for me complete a graft while sitting on my scionwood cooler. If you can't make the proper grafting cuts comfortably, your grafting success rate will suffer. I always choose the site for grafting first, frequently cutting the stock tree back drastically. I then rummage through my scionwood supply to find the perfect scion. In this case, a 3-flap graft, the scion should be about the same diameter as the stock (photo at left).
In preparing the stock for the 3-flap, the technique calls for making 3 vertical slits in the bark. When I make these cuts, I keep my knife in the center of the stem and slice downwards making sure to follow any curvature in the stem. In the photo at right, you can see that my slit curves to the left about two inches down to follow the bend in the stem. By keeping your slits right in the center of the stem on all three sides you will end up with three straight flaps.
I always make the three shallow cuts on the scion before I try peel back the flaps on the stock (photo at left). I make sure that the cuts on the scion are deep enough to expose wood on three sides. When I see white wood, I know I've got cambium exposed.
Once my scion is prepared, I peel back the three flaps, making sure that I only handle them of the very top edge. I use my clippers to hold down the flaps so I can remove the inner wood (photo at right). Once again, I try to keep my figures from touching the inside of the bark flaps.
Before inserting the scion, I always start wrapping up the graft union (photo at left). A couple of wraps around the base of the flaps helps to create a bark "tube" that can accept the scion. I hold the tape tight while I force the scion in place.
By holding on to the tape, the scion will sit inside the bark flap tube all by itself (photo at right). At this point, I check the alignment of the flaps of the stock and cut surfaces of the scion. Sometimes, I'll pull the scion back out, then rotate it to see it I can get a better fit. Once I'm satisfied, I'll wrap up the entire graft union.
When wrapping a 3-falp graft, I pull the tape as tight as I can without snapping the tape (photo at left). My goal is to make sure that I press each bark flap up firmly against the scion and drive out all air gaps.
Once the graft is firmly in place, I cover the graft with aluminum foil and a plastic bag (as I do with all my field grafts). Before leaving this tree, I attach a bamboo training stick to the tree below the graft union (photo at right). In a few weeks time, I'll have a growing scion that will need support and training to a central leader. I also cage all my new grafts to prevent deer from browsing on new scion shoots.
Since the 3-flap is an almost fool-proof grafting method, some folks become temped to place multiple 3-flap grafts on a tree such as the one pictured at left. However, I don't recommend that practice because it gives the tree to many opportunities to grow around the grafts and you'll get week scion growth.
Instead, I sit on my cooler and cut back the tree to around two feet and prepare to make a bark graft. I find that cutting a small tree back like this helps to force the tree accept my scion. Then, when the scion starts to grow, the new shoot grows so vigorously that training to a central leader is easy.
Once I complete the bark graft, I make sure to attach a training stick (photo at left). Fast growing bark grafts will needing tying to a training stick as soon as possible to prevent possible wind throw. I'll also cage this tree before moving on to my next tree to graft.
