The plums from seed will not be true to the form of the parent. I don't know how close it will be having never grown plums from seed. In general most fruits do not come true from seed since the seed will be a cross of the parent and the pollinating plant.

If you want an identical tree you need to take some wood of the original tree and graft it to a rootstock. If you wanted to avoid buying anything you could grow out a few of the seeds and then in a few years graft the original tree to your seedling trees.

Scott

Way to go Scott always thinking long term.

"If you wanted to avoid buying anything you could grow out a few of the seeds and then in a few years graft the original tree to your seedling trees."

Grafting onto a rootstock of the same tree at first glance may not seem to make much sense. But the juvenile period of growth would actually in most cases be shortened, meaning the tree will bloom and bear earlier, as well as assuring you will get the fruit you want. Plum trees from my personal experience have been grafted onto rootstock for at least 75 years and I would buy a rootstock suited to your soil and climate to graft my old plum on. Al

Grafting is much easier than you might think. Read up on it this winter. And start grafting in the spring. I just started grafting this spring and had about 80% success rate. I only used grafting tape, electrical tape, and a sharp knife. If you want to get a jump start on your crop, buy a larger plum tree from a nursery, Home Depot, etc. then graft to it. I would still have a backup with the seedlings/graft mentioned above though too.

Since you're here in Portland, go to the Home Orchard Society's page to learn about their rootstock sales -- typically every March, and inexpensive, too.

If your goal is a good fruit tree of the same type you've been eating, just buy the rootstock appropriate for your area and graft onto it.

You'll get the best results that way.