I am in zone 5-5B . What time of year for field grafting . I know they need more heat to callous . Thinking early June to get enough heat . I realize now I have been grafting too early .
That’s exactly, correct. We were going to do a walnut grafting demonstration Jerry at Red Fern Farm on walnuts and had our date for the last week of May. It was cancelled, ultimately. So, late-late May and until mid-June is the sweet spot.
Since you’re in IL and right near me, you couldn’t get better information than this.
NW IL zone 5b
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Thank you . I saw a video on bench grafting walnut and they put theirs in totes with damp sawdust and held them at 28-30 C for three weeks while they callus .
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I don’t have advice but using the hot callus system on the Guides section of the group with black walnut rootstock being dormant and grafting dormant scions, they bled. I talked to Cliff England about it and he said they bleed when dormant on pipes. He uses barely moist compost to contain his bareroot walnut trees on a hot pipe (he said something like “dry compost”) and said that helps.
Now the same callus pipe I use a guy over in Europe grafts Juglans regia on regia and didn’t have any bleeding issues. Different species, different result.
I just don’t graft them. I did them once and they all bled (75-80 trees) and I got (2) survivors.
You can’t sell them anywhere.
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I just discovered this interesting procedure for bench grafting walnut, basically using a root graft:
Black walnut bench-grafting procedure reduces stock suckering.pdf (1.9 MB)
Anyone try anything like this?
Some takeaways:
- Reduces need for post-graft removal of rootstock shoots
- Apparently a cleft graft works fine in this situation
- Milk carton makes a good impromptu pot then turns into wind shield at planting
- “Discarded” stem portion of rootstock will re-root (I’m assuming this is because some of the stem is from below the root collar)
The one thing I’m not understanding is why a mist system would be required for this method. Is that just to slow down scion growth until the graft has time to heal?
Misting grafts is almost always to prevent the scion desiccating. Usually the roots can take up enough water to contribute callus. The scion does not have water unless it is misted on the stem.
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That’s what I thought. What confuses me is that the author specifies a wax dip (I would probably use parafilm) but also says misting is necessary. I know this is an older publication, but is this a “belt and suspenders” situation, or are black walnut extra prone to drying out?
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The cut off tip is being dipped/painted with wax but not the scion and then the union are covered in wax but not the roots.
It is odd to me also, Jay. If the roots and the union are inside the milk cartons with perlite/other that is kept moist for the callousing and for the roots, then I wouldn’t understand why the wax is there…
Another system commonly used is a wooden frame on the ground with heat lines running across the bottom and sand fills it. The sand is kept moist and the grafts are tucked into it and the box/large frame is covered with poly. The poly is opened periodically to keep it from becoming to moist inside.
I’ve seen this inside hoophouses where during winter they’re grafting at picnic tables inside and tucking the grafts away to callous - this way. Unions are always buried, also.
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This person is making it really difficult. A plastic cover over their milk cartons would achieve the same thing as a mist system. Or, waxing the whole thing minus the roots.
The whole thing is a bit suspenders heavy!
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Up date my grafts failed again. Bud grafting now. Hoping for some takes.
Inlay side grafting requires a rootstock about 2 inches diameter. Select a scion and cut a slant on the base about 2.5 inches long. Hold the scion with the cut side against the bark of the rootstock and cut on both sides so the cut out bark area will exactly hold the scion. Cut at a downward slant across the top of the bark flap and lift it up so the bark separates from the stem about an inch. now cut a slant across the bottom of the scion on the opposite side of the flat cut at the base so that it forms a sharp wedge. This cut should be about an inch long. All dead or off colored wood should be removed from the scion so that only living tissue remains. Now insert the scion pushing downward into the slot under the bark flap until the cut area of the scion is entirely behind the bark flap. Cut the bark flap off so that it still covers the cut surface area of the scion. Use 2 small nails to tack with one through the bark flap and scion and the other through the scion near the top of the removed bark on the rootstock so the scion is firmly attached to the rootstock. If everything looks good, cover it with grafting wax. Leave it entirely alone for exactly 10 days, then cut the top of the rootstock off 2 feet above the graft. As the scion grows, attach it to the stem of the rootstock for support.
When to graft: When temps consistently reach 70F and soil moisture is relatively high, in your area, about the 1st of June.
Advantages: no bleeding from the rootstock is the primary advantage of inlay side grafting. It takes advantage of the callusing potential of the rootstock which has an actively growing top.
You can also use greenwood budding with reasonably good success in late July and early August. Do you need info on greenwood budding?
I’m curious, what varieties are you attempting to graft?
Doing greenwood budding of Kenworthy butternut onto black walnut seedlings. Any tips? I have another variety that I have not grafted. Grafted trees from Grimo 2 years ago.
What I have used is a coin purse bud with leaf still attached. The stem portion of the bud should be at least 1.5 inches long. Cover the bud with a wrap of fairly heavy plastic. I’ve used 1 gallon freezer ziploc bags with success. Other than that, be sure to cut only large healthy vegetative buds. Small buds almost always fail.