Shiro - super reliable, way oversets, birds less of a problem due to color, disease resistant, average on fruit rot, taste good, better if left on to deep yellow color.

Superior - reliable, disease-resistant, taste very good, can be inconsistent in flavor/texture (can be too sour and not sweet, or too mushy).

Those are the only ones I have grown on your list. They are very good plums, definitely recommend. My favorite Japanese plum is Satsuma, and Santa Rosa is also excellent now that the tree is ten years old and sets a good quantity finally.

Scott

Good to hear Scott since I planted a Shiro, Superior, Satsuma, and Pipestone plum this year!

I've got Superior, and although the plums are small, they are extremely good tasting. Picking at proper ripeness is important.

Bruce,

Stark Bubblegum is the same as Toka plum. Medium size, sweet, very fragrant, and juicy. Very good use for pollination other plums.

Tony

Shiro has a very good tree shape...open.
Starking Delicious is tasty if fully ripe, but the tree is very growthy and subject to black canker badly.

Here in the Northeast (southeastern NY), Shiro is the most popular commercial J. plum. Stanley the most popular Euro. I would grow Castleton over Stanley as C bears as reliably but can get more sugar. Shiro is worth having for reliability, but I agree that Satsuma is superior but is probably not as cold hardy. Certainly Santa Rosa isn't. Too bad no one sells Earli Majic which ripens before Shiro, almost with Methely but is a higer quality plum than either IMO. It is reputedly more cold hardy than SR and in my experience that seems the case.

I have Satsuma and my neighbor has Santa Rosa. They both have gotten through a couple of tough winters here. Her Santa Rosa is loaded this year and wow are they good. My Satsuma is not ripe yet, and this is the first year it is bearing. Of course it is on seedling rootstock 'cause I bought it before I knew anything. Here in Colorado the issue with Japanese plums seems to be their early bloom, but they seem to be hardy enough.

I also have Toka, which does taste like bubble gum. I have eaten quite a few Stanley in my day and it is the least favorite of any plum I have had. I would never intentionally plant one; the flesh is dry and not very sweet.

I can only commment on two from your list. I like Stanley.
However, I am very partial to European prune plums.

I do not like the terribly upright growth on a stanley plum
but have learned to live with it. As long as it produces the fruit, I am ok.

Superior? I friend of mine grows numerous jap-american hybrid plums for fresh market and commercial jelly making.
He claims Superior makes the best plum jam for flavor out
of all the Jap/american plums he grows.

Personally I hate the flavor of Superior. It reminds me of
bubblegum. I have always enjoyed Underwood although the
skin is tough. The flavor is sublime! Oh to sit under an
Underwood tree and gorge myself upon the lucious ripe fruit! Usually I eat too many of them as I cannot stop.

When I was a child we grew an unknown yellow plum that I have never seen anywhere else until I saw the picture of St. Catherine plum in the Raintree catalog. Just like what I had in my youth! The skin would wrinkle when ripe.

Spartan-

I really like Superior. Have you tried Alderman?

Superior tastes like bubblegum? That's certainly not true of my tree.

Thanks for the imput.

I agree about Superior and jam, I have yet to beat the Superior jam I made over ten years ago. I have about ten pounds of Satsuma sauce in the fridge now that I need to boil down this weekend, its going to be good but probably not up to the Superior.

Scott