[nafex] article "Learning Grafting"
tanistanis at hotmail.com
Thu Jan 16 16:22:05 EST 2014
Somewhere I have a CD with photos. Not sure how to add them, though.
The graft union's mending begins with formation of callus, then this differentiates into the functional parts. These steps happen best in conditions of enough moisture and oxygen and proper temperature. Apples and pears manage this in a range of conditions, and pears have the widest window. So begin with pears if you can.
Collect good scionwood. Choose "one-year wood", that which was new green growth in the past growing season. I've succeeded with two-year wood, but this is more likely to have fruit buds, which don't grow much. The more vertical the shoot, the more in the sun, the closer to the top of the tree, the better the scionwood. Should be free of disease, and it should have hardened off properly, i.e., matured before autumn and has no dead leaves nor petioles attached. Collect before the first spring growth on ANY tree/shrub in the spring. Ideally, collect before any extreme winter weather, especially thaws. Most lessons recommend "pencil sized" scions. I prefer "thinner than a cheap ball-point pen, but thicker than the ink tube."
Clip off the tips of the scions, especially if these are much fuzzier than the rest-- didn't mature fully. If tips look OK, they can be used for grafting, but are a little awkward to handle and then want even more water for proper growth than do the lesser buds. Put scions into clean, labelled, plastic bags. Put these into another plastic bag which contains a wet paper-towel. Store in a refrig which (ideally, but may not be practical) isn't opened often, and contains no fruit and no veggies older than one week. Check the moisture of the paper-towel occasionally, adding water if drying out. Also check for bud growth. They shouldn't break dormancy if the refrig is cold, and collection was before much spring weather. Pears and crabapples and fruit buds tend to grow first. Some people store their scionwood in the freezer. I've never tried this, but it might be a way to store scionwood until budding season, or even the next spring's graft season.
"Bench grafting" refers to timing: it's done during the dormant season, on rootstocks which were dug in the autumn and stored. I prefer "nursery grafting" in May, which for me gives better success rates than bench grafting. But, bench grafts might be done on rootstocks which you've just bought, then you plant them in the nursery row in the spring; while nursery grafting takes more planning. Rootstocks grow in the nursery row for a year, then the grafting. Try to finish before Memorial Day. If you run late, the buds may not grow much (then they have another year in the nursery!) but if they grow any green leaves which last til autumn, they should grow well the next year.
Use "splice graft" method for the union. It's the safest and easiest, maybe also the fastest. Use any good knife with a straight edge and not much side-to-side play. Sharpen it, wash it, and use a separate tool for cutting the wraps. My preferred wrap is rubber electrician's splicing tape, also called self-fusing rubber tape. Parafilm is a better wrap for scrawny scions. Both tapes need a pre-stretch. Remember to knock off any buds-- on the rootstock and the scion-- which would end up under the wrap. A demonstration of all this is nice, but really it's just trying it, then practice, that matters. Many graft demonstrators forget to mention that the scionwood should end up with only one or 2 buds. I've forgotten to tell students that the rootstock's shoot, where you are grafting to, should be cut back so you are using the woody part instead of the new green part.
I'm in southern WI, where most Mays are humid, so I don't bother coating grafts and scions with wax. I don't shade them. No fuss except for extra water, a little fertilizer if needed. For storing scionwood, I don't dip the cut ends in wax. The ends dry out anyway, and you have to cut off anything with wax on it so it doesn't contaminate the graft union. I avoid shipped scionwood, unless I can go get it and haul it in a cooler with ice. I get 1/2 the rate of success from shipped scions. Maybe they get too warm for too long.
Eventually the biggest problem you will have with grafting is what to do with all the trees. Not joking. Have a plan to transplant and stay ahead of trees growing in the nursery row a year or 2 or 3 too long.
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