others will have more authoritative answers, but here's a start:

yes, everyone can get scions. those that are providing scions will be cutting them now in the dormancy, and then refrigerating them. one normally waits until the cambium is slipping to graft, so mid-March or even later is perfectly fine. as long as the scion is dormant, the rest of the tree's blooms don't matter.

it's perfectly possible to graft new varieties on, but i wouldn't try to "cut out" the existing graft union. just add a new graft, either a rind graft in the main stem, or a tongue and groove on a branch where it's small enough (or both).

good luck!

.b

I'm not 100% sure, but I think the March event isn't so much an "exchange" as a "distribution" event.  i.e. don't bring anything but your admission money, wish list, sharpie, masking tape, and a plastic bag or two. I also bring a small backpack to carry things so I can have my hands free to use my sharpie. 

The main point of the event is to pick up exactly one of each of the varieties on your wish list (which you are likely, but not guaranteed, to find).

There are of course exceptions, such as the scions that I bring from my relatively new seedling apple "Miss Jessamine".  But I expect those to start showing up from the regular sources before too long.

I have also been known to do trades in the parking lot, coordinated via this forum :-).  E.g. larger quantities, bare root plants, etc.

Yes, the HOS "scion exchange" is really more of a "distribution" of scions, although the implicit premise is that active members with accurately identified fruit trees will be willing to donate scion wood to the event for others to acquire.  Scions of dubious identity shouldn't be contributed because the correct identity of the clonal material is vitally important.  

That being said, if you have scion-wood material from an apple or other fruit tree that you believe is worth cultivating but for which you don't know the original name (--if any--), you could still contribute scions with the appropriate information about the parent tree, along with descriptive information and clear indication of its origin.  If you have a particular name that you have given to the unique tree, then include that with the caveat that it is a name that you gave to it, and that it isn't a generally recognized name.  A description of the fruit and its qualities should be included in the information.  There is certainly more than one example of a hedgerow tree, or volunteer seedling in a pasture, that subsequently became a widely cultivated tree of merit.  

By all means try your hand at grafting fruit trees.  Early-on it might be a bit intimidating, but it's such a wonderful ability to have.  My first (--and, I believe only--) exposure to grafting was in my Grandpa's garden in southern California where one summer I saw my green-thumbed Grandpa Chet grafting an apricot scion to one of his established apricot trees.  He told me that it was a different variety that he had acquired.  ...Wow!  What a fascinating ability to have!  ...It was several years after when I made my own first graft, but with the first success and an understanding of the underlying requirements in the process, I was pleased to add a unique talent that surpasses so many others.

Grafting is the kind of talent and "artwork" that needs to be passed-on to future generations of kids....

Reinettes (Tim).

Reinettes said

By all means try your hand at grafting fruit trees.  Early-on it might be a bit intimidating, but it's such a wonderful ability to have.  My first (--and, I believe only--) exposure to grafting was in my Grandpa's garden in southern California where one summer I saw my green-thumbed Grandpa Chet grafting an apricot scion to one of his established apricot trees.  He told me that it was a different variety that he had acquired.  ...Wow!  What a fascinating ability to have!  ...It was several years after when I made my own first graft, but with the first success and an understanding of the underlying requirements in the process, I was pleased to add a unique talent that surpasses so many others.

Grafting is the kind of talent and "artwork" that needs to be passed-on to future generations of kids....

Reinettes (Tim).  

Let me plug the grafting class for the locals. HOS in combination with CCC Clackamas Community College, host/teach a beginning and intermediate bench grafting class Saturday 2/29. Registration is through CCC. Location is on the CCC campus in Oregon City. Details are on the events page on the header above. You get guided practice, a choice of scions and a rootstock for the price of admission, so you come away with a tree that you have put together, (or 2 if you take both classes).

I'm hoping there will be some Firecracker Crab scions and Sargent "Tina" crabapple scions. As well as a few others.  Gotta get my wish list written up.

And the math tests are killing me.  I'm old!  I've forgotten my math.  Hoping it doesn't get into algerba, or worse, trig.

Pugs said
....Past events (I've read) have had a person there would would sharpen your shears for a small fee, someone selling grafting tools....
...But what else?
...Cuttings for grapes?  What about blueberries? Raspberries? Elderberries? Rhubarb? Asparagus? ....

Pugs,

In a given year there are usually many varieties of apples and pears available as scionwood, as well as a lesser number of plums and cherries, and a diversity of odd-ball things.  Usually a surprising number of grapes available as dormant cuttings (--all the grapes that I have were started as HOS cuttings--).  

There are vendors for various potted fruits and so forth.

Two or three years ago I finally remembered to bring my pruning shears to have them professionally sharpened, but it coincided with the first year (apparently) that the guy wasn't there.  However, there is someone there who sells replacement parts for some pruners (--like my Felco 8 hand-pruners, for which I got a replacement blade last year).  Don't know what else he has, but he had a lot of stuff.  One of the other members may have more information regarding fruits and accessories. I'm probably blinded by my own priorities.  (--Oh yes, and there are a nice diversity of books for purchase.)

Once you get a handle on grafting techniques, and begin to master the process, you'll find that the diversity of material available at the HOS "scion exchange" is nearly priceless.  Step 1:  Understand the process of grafting, i.e., as to what's required to make the graft successful.  Step 2:  Sample a broad diversity of fruits so that you know what you really like.  Step 3:  decide which ones you really want, and that do well in you local environment and soil, and that you have room for in your yard or on your property.  Step 4:  continue educating yourself on what your plants need in order to make them thrive and be productive.  

Gardening, orcharding, agriculture, all require that the caretaker know the needs of the individual plants and strives to give them all the care and nutrients that they need individually.  Know thy plants.  Your care and concern go a long way toward success and, ultimately, a pleasant harvest best savoured by the caretaker.

Reinettes.

Pugs said
I'm hoping there will be some Firecracker Crab scions and Sargent "Tina" crabapple scions. As well as a few others.  Gotta get my wish list written up.

If they have an ornamental crabapple section then I will put a few scions there of 'sargent tina'. If not then see me at the volunteer grafting area.

My order is going in the mail today.  I hope it isn't too confussing. 

I included enough for everything I put down, including the alternatives.  If they are out of something I'd like, well HOS can keep the money for those as a donation.

Just noticed I had a few missing from my scorecard above: