In a backyard in Westwood, this avocado clearly has been grafted. The main trunk and upper structure on the left is one avocado variety while off to the right, the lighter bark is evidence of a different variety. This graft, probably made more than forty years ago, created a tree with two varieties that fruit in different times of the year for a longer harvest. The variety on the right, at one time, was just a short piece of wood, a scion, which was grafted to the tree. This avocado is a graphic example of how lasting a good graft, a union of science and art, can be.
From the West Los Angeles California Rare Fruit Growers Chapter newsletter about the upcoming scion wood exchange on February 14th:
Scion Wood Preparation
Prepare a solution of one part bleach to nine parts water. Immerse your scion wood cuttings in this solution for about ten seconds before placing them in the plastic bag. This will insure the prevention of the spread of most diseases from one garden to another. One infected twig can kill the whole tree onto which is grafted, and possibly surrounding trees too. A newly infected tree from your garden may not be showing visual signs yet, but without proper processing of cuttings you could unintentionally be responsible for killing trees in the gardens of many of your fellow members.
Select straight wood from last year’s growth and cut as near to our scion wood exchange date as possible.
Wood should be ¼” to 3/8” diameter (pencil size) and contain several buds.
Cut to lengths that fit easily into a Ziplock-type bag. Cut with a slanting cut on the top (distal) and a flat cut on the end that would have been nearest the trunk (medial).
Bundle by variety in a moist paper towel(s) and place in a Ziploc-type bag, leaving a slight opening in the bag for the wood to breathe. Put only one variety in each bag. Make sure that the towel(s) stay damp for as long as the wood is stored..
Label the outside of the bag with the fruit type and variety as well as any additional information you feel is pertinent (i.e. minimum chilling hours; needs pollinator; vigor; area where successfully grown, etc). It's nice to add your name so that those collecting your wood know where the wood came from and can ask you questions about the parent tree.
Keep the scion wood bag in the vegetable bin of your refrigerator until the morning of the exchange. Be careful not to let the scion wood freeze!
At the exchange, please wait to make your selections until directed by the Chair. Please limit your selections to two of any one variety until everyone has had an opportunity to collect wood. Then feel free to go back. Please do not collect wood you do not plan to use.
What to do with your collected scion wood after the scion exchange:
If you don't plant to graft as soon as you get home, remember to add moist paper toweling to the bag and refrigerate until you have time to graft. Do not freeze! Be careful with the label. An all too frequent mistake is to put the label in the bag with the wood. When you add moist paper toweling, the label becomes unreadable.
N. B. All meetings and activities of the West Los Angeles CRFG are open to the public. You do not need to be a member to attend. However, membership is only $8 a year and puts you on our mailing list. Membership also helps pay for our meeting sites, supplies, and mailings. Please note, paid members who bring wood choose first! You can click to WLA Chapter's site or to the California Rare Fruit Growers site.
If students want to participate in the scion wood exchange, I will make a few of TLG's trees available to them for wood collection.
This is our first field trip. The wood collected will be used in subsequent classes.