Thread: How to Top Work a Pecan Tree to Change It's Variety

I'm making a totally separate thread with this subject since it is heavily researched by Grafters.



I harvest my Pecan tree Scions in February. These were stored in a refrigerator set to 40 degrees (one I use for this purpose mostly). You want healthy first year's growth, pencil diameters seem to work best, straight sticks if possible, I like the larger buds on the Scion wood but the small ones grow into new limbs too, and add 1/2 a damp paper towel (very rung out) to the bag if it will be a while before you will use. I don't use added moisture but harvest my Scions the day after a rain. Seems they don't mold as easy.



Tools of the trade. This folding saw has been in service for I don't know how many years but it has top worked over 150 trees most much larger than the example today. 91% Alcohol for disinfecting all cutting implements. Various Grafting Knives, I'm left handed and most knives are for right handed people. Reason they are Left & Right handed is a grafting knife blade is only sharpened on one side. Videos online show the technique to properly prepare the scion using the proper grip and cutting technique. Linerless Self Vulcanizing Tape is my go to product for sealing my graft work today but I along with many others have enjoyed great success using Duct Tape too. Jumbo Rubber Bands really improve the success rate over Duct Tape when it comes to keeping compression on the graft till it heals. Aluminum foil is used to reflect the Sun's heat, and Grafting Wax is used to seal & waterproof your work.



Your pruners must be clean and disinfected. Here are mine after pruning all my fruit trees of broken limbs from the Tornado recently. All that sap on the blade needs to be removed. I use a red Scotch brite pad to keep my blades clean.



Now to the task. This Pecan tree was struck a glancing blow on it's side by a falling pine tree from the neighbor's property. The pine was not real big and the Pecan tree was 10-11 inches in diameter where it was struck. I didn't think much about it but the Pecan started dying on that side first. By winter it was dead over 1/2 way thru. I decided to cut it down but leave enough of the trunk sticking up that if it survived till spring sunlight shining on the stump bark remaining would make the roots sprout suckers. The bet paid off. I allowed all the suckers to develop around the stump keeping the stump alive all the way around but kept upwards growth regulated by way of topping all the sprouts but one. Eventually by last winter I had removed all the extra suckers as the remaining developed enough to ensure the stumps survival.



Not the greatest picture but you get the point. I topped the strongest shoot leaving 2 branches below my cut. The remaining branches will continue to draw nutrients from the stump keeping this sucker alive till the graft heals. Now after you saw off the top a bit of knife work here goes a long way. I shave the top of the cut all the way around with a very sharp knife. This makes the bark graft heal much better than a rough saw cut alone.



After choosing the first Scion a fresh cut is made at the bottom then a bevel cut is made on the opposite side on the lowest bud.



next on a flat part of the tree you made a vertical cut a little longer than you Scion bevel cut. Using the knife blade itself or the Bark Lifter (the bump on the top of the blade) you open the cut helping start the Scion to be inserted.



Over the years I have discovered a little extra Scion bark prep helps me maintain a almost 100% success rate top working Pecan trees. I square my blade to the Bark and lightly scrape the outer bark away revealing the Cambium underneath before inserting the Scion. This provides a superior amount of Cambium contact between the Tree & Scion.



When first inserting the Scion into the Bark leave quite a bit of the Bevel Cut showing on top of the Tree. This will be dealt with later.



To double my chances of success I add a second Scion. On much larger trees I have used as many as 6.



After both Scions are in position I use the Linerless Rubber Self Vulcanizing Tape to wrap the graft well. I make sure and put enough tape to waterproof the work but never rely on just that.



After the tape job is complete I cut the jumbo rubber band and wrap it tightly around the tape compressing all the work well. Once the rubber band is installed I tap the Scion wood down further till just a small part of the Bevel Cut is revealed improving Cambium contact even further. Then again I work to waterproof the work some more using the same tape.



To reflect the Sun's heat off the graft till it heals I use aluminum foil, here I'm cutting two slits opposing each other, I slide the remaining connected aluminum foil between the two Scions, and then wrap the aluminum foil very well around the entire worksite.




Time for the real waterproofing and insect control. I use a scented candle heater to heat my grafting wax before applying all over the top of the graft and the tips of the two Scions. Many instruct you to use plastic bags but I have found if any excessive rain or bleeding of the tree sap and the bags rot the graft joint. Since I switched to this method to execute a Bark Graft on any tree I'm sitting at 100% success. I hope you find this information useful, Grafting can be a very rewarding hobby.