Thursday, February 8, 2007

PECAN TREE GRAFTING

Improve Quality & Quantity
of Your Pecans


This photo shows some nice native pecans (on the left) and some from one of my grafted trees (on the right) Photo taken in fall of 2006.




Big pecans do not come from improved or modified trees or seeds. The early settlers found lots of small pecans and also found some were larger than the others. Someone got the bright idea of cutting a limb off one of the trees that was producing large nuts and grafting the limb onto a tree that had been producing small pecans. Thus, pecan grafting was born. It takes a lot of care, patience, practice and luck to get the donor tree's limb (scions) to grow on the tree you are trying to improve. I am sure that moisture in the ground for both the donor tree and the host tree has a lot to do with whether the scion survives. Some years, I have had a 50% survival rate, some years it was only 10 or 15%. I have found that I can increase my survival rate dramatically by putting three scions on a tree instead of just one scion. By doing so, I have found that I can get at least one scion to grow 90% of the time. Sometimes, all three survive, leading me to believe that the ground moisture, weather conditions, or something was just right for that tree to accept the graft.

The time to cut and store scions to graft onto pecan trees is
after Feb 1st. This is done to improve the pecans produced by a tree. A pecan that is planted has no relation to the pecan it will produce 30 years later. You may plant a large pecan, wait 20 to 30 years and find it produces pecans the size of marbles.

This photo shows some pecan meats from my grafted trees (on the top) and some from a native tree (on the bottom).

Also notice: The native meats are broken. That is the best I could do. The grafted meat comes out with both halves as one piece, unbroken. It sure makes it easy to shell enough for a pie!



The only sure way to predict what it will produce is to graft it. Trees 2 feet tall that have the diameter of a pencil are ideal to graft. Trees 30 feet tall can also be improved by grafting but the best way to do it is to just cut them off at about 6 feet in height., leaving some limbs to support the root system (to be cut off in a year or two). They recover their original height very quickly, growing 10 to 12 feet per year. Growing is not a problem, growing too much and breaking off is a problem. The new growth has to be braced up and supported with a 2x4 or something sturdy screwed to the tree trunk below the graft and the new shoots tied to the it. These new limbs get very heavy and are very susceptible to breaking off in a 40 or 50 mile per hour windstorm. I suggest bracing the new limb and also pruning off some of the new growth so the wind will not break it off.

Another choice is buying a grafted tree from a nursery. The only problem with that is: A pecan tree has a long straight tap root that is at least as long below the ground, as the tree's height above ground. Typically, when a pecan comes up in the flower bed, where a squirrel has planted it, it may be 2 inches above and 4 inches below ground. If you wait any longer than that, it is almost impossible to move them. So, if your nursery or home improvement center is selling a pecan tree that is 6 feet tall, they need to have it in a bucket that is at least 6 feet tall! In a five gallon bucket, they are root bound and will never recover. Dry rooted trees have had their tap root cut off. That's like cutting off the legs of a dog you just purchased to get him in the car! Money wasted. Planting nuts is the best way to get a pecan or walnut tree. There is no money in it, so no one tells you.
The best alternative is (1) to loosen the soil, plant about 6 good fresh pecans in the fall that were grown that year or (2) Hold over the pecans in the freezer and plant them in the spring. Plant them at a depth of ½ inch, just like the squirrels do. Mark the spot where you planted with 2 stakes, one on east and one on west side. (or you'll forget where they are) The size of the pecan does not matter when planting. Small, big, round, pointed, it makes no difference. It is going to be grafted with another variety. This graft does not know it has been taken off one tree and placed on another. It thinks it is 30 years old so it will probably produce pecans the next year. Just as I mentioned elsewhere, this can be a problem with weight breaking the limb off so they must be supported. Also, at this point it is better to pick off the pecans in favor of better stronger limbs. That little 4 inch, pencil sized graft is going to grow to be 50 foot tall and 4 feet in diameter and produce 100 pound sacks of pecans for you and your grandchildren! It could even add thousands to your property's equity, should you decide to sell someday.













The grafting procedure is very simple:
Either find a tree that has good, big pecans and cut off a pencil sized limb that was grown last year, or order scions from a dealer.

If you cut your own, on or about Feb. 1st, cut off small pencil sized limbs of last year's growth, with nice fat buds. Dip the ends into Elmer's glue. This seals to prevent them from drying out.

Put the scions in a zip lock bag, along with a damp paper towel and store in the veg. crisper in the refrigerator until June 1st.

Oklahoma State University has some good fact sheets on grafting available
at:

http://pods.dasnr.okstate.edu/docushare/dsweb/View/Collection-176

The grafts I recommend and use are:
F-6204 Bark Graft ...................
Use this on trees or limbs larger than a pencil
F-6230 Four Flap Graft............Use this on small trees or branches.
Another site is New Mexico State University at:
http://www.cahe.nmsu.edu/pubs/_h/h-634.html

You need to either cut your scions or get in touch with a supplier and order before June. You should also consider they need to be kept cool and the mail truck gets hot in May, so order early and refrigerate.



Neither of these pecans is ripe yet. I picked the one on left off an ungrafted tree, AKA: "Native PecanTree", although all pecan trees are "Native" (not improved in any way except for grafting one onto another). The one on right is from a grafted tree, 50 feet away. Which would you rather have?






This is a little tree I grafted in June of this year. Look carefully and you can see the brown scion and the black tape holding it onto the original tree. The green is the new growth sprouting out. It's hard to believe, but it will someday be as big as the one pictured below.






















I grafted this tree 5 years ago.



FOUR FLAP GRAFT:


Graft to a tree the size of a pencil


If you can, cut above a spot that has
smooth bark. Most pruners have one side
that cuts and one side that is flat. Put the
cutting side of pruners on the bottom so
you don't damage the tree. 




Make 4 cuts with sharp knife on the bottom
of the scion. Do not touch the green cambium
(under the bark and above the wood). That is
the part you are grafting; not the wood or bark.


I marked the 2nd one with ink, making it easier to see the cuts.  



Make an X with knife on top of the tree.


Peel back the bark and cambium with thumbnail
or knife edge.




Cut out a piece of wood from the tree 
a little longer than the cuts made on the scion.


Insert the scion into the tree and align the
cuts with the flaps. Shade from the sun with
your body and block from wind. Work swiftly.



Wrap with a small piece of masking tape 
to hold the tree flaps and the scion together.  





Wrap with a good quality 1 inch wide electrical tape. 
Put 2 wraps around the flaps, and then start pulling 
and stretching the tape.  Pull and stretch the tape, 
make another wrap, pull and stretch again, 
repeat making the wraps as tight as possible 
without breaking tape.

This is to make the joint stronger, make better
contact between the cambium of tree and scion,
and to make it airtight.  

Remember, DO NOT touch the cambium.




It should look like this, You can wrap 
over this if you are not satisfied.



The problem with black tape is it heats up
from sunlight. Cover with aluminum foil or
masking tape to keep it as cool as possible.
Tape or tie a limb or piece of wood onto
the tree and scion for the birds to sit on
and protect from wind damage.




If the scion survives,  year after making the graft, 
make a cut from top to bottom through the tape 
to relieve girthing (choking) the graft.  After it 
is cut, the tape will fall off in a few months. 

Don't be afraid to snip off a few leaves as
the summer progresses to make the wind
load lighter. The buds on the scions can
grow terribly fast. I have had an 1/8 inch bud
grow to 12 feet long in one season. On a big tree,
if you cut off most of the limbs, the roots
send up so much sap, it makes for lots of growth. 


The new limb is very tender and fragile and will
break off in a 25 MPH wind. For this reason,
you must tie on a brace for a year or two. Use a 2x2inch board or the equivalent.  I use old limbs I have cut off of other trees;  elm, cottonwood, oak, etc, it doesn't matter.  Just tie it securely to avoid wind damage.


Good luck.