Self pollinating? How can you tell?

Is there a way to tell if a plum tree is self pollinating? Are all plum trees of a type the same or is it tree specific?

this doesn’t really answer your question, but even with ‘self pollinating’ you usually get better fruit set with another pollinator present. maybe graft something else on there to be sure? i rarely trust the ‘self pollinating’ moniker.

If the seller wants to make a sale, then he or she should tell you if said plant is self pollinating or not.
"The Green Gage is a very popular old fashioned English plum that grows well over a wide range of climates. It is a greenish-yellow, very sweet and juicy plum. The self-fertile Green Gage plum produces heavy crops that ripen in July. Due to very limited supply of Greengage Plum trees, you'll need to order from Willis Orchards now to get yours! (300-400 Chill Hours)"

"Gardening skill: Experienced
Picking season: Late Early September
Self-fertility: Not self-fertile
Pollination group: 3
List of other varieties that will pollinate Old Green Gage"

I would never plant just one fruit tree, the only way to use one trunk is to plant a tree that has four plum varieties grafted on it, these limbs will pollinate each other.
It is a fact of life that even the best self -fertility tree will do better with another tree of the same or at least blooming at the same time.
I was taught never buy a horse, car or tree from someone who does not know it history. It was the best advise, I have ever been given & with the internet one can learn many things at home.

Note: this is true for all fruiting plant.

Sonja Draven wrote:Is there a way to tell if a plum tree is self pollinating? Are all plum trees of a type the same or is it tree specific?

No, all plum trees are not the same, in my first example the green gage is self-fertile at Willis Orchards.

The next example is from a different nursery, who also said:
"Old Greengage is generally considered partially self-fertile but having another pollination partner nearby will definitely help to improve cropping. Old Greengage can be pollinated by most other plum and gage varieties."
www.orangepippin.com

If you buy or are gifted a tree or grew one from a seed, then you need to do the research to find out if you tree is  self-fertile.
If you know the name, then half the battle is won, if not date when it blooms & call you local extension agent, to see what varieties are blooming in your area. If they are close, with in 800 yards then you may get a good crop. Bees can travel miles to get nectar & pollen.

Thanks, all!  Lots of great info!

I have a huge, beautiful yellow plum tree that produces abundantly every year. Nearby is a smaller purple kind that flowers like crazy but never delivers more than a couple plums. (Last year I got one perfect plum from it.)

Sounds like the smaller tree is still worth the real estate. :)

Sonja, have you observed if the two plum trees are in bloom at the same time?

Stacie, They don't fully but there is definite overlap. I have a couple pear trees blooming then too but I assume that doesn't matter...

probably not. if you need the space for something else, you could always graft a couple sticks of your mostly-flowers plum onto the other one.

Here's my guess at what may be the issue.

The bigger yellow one may be a Shiro plum, a popular self fertile Japanese plum, that is known for producing tons of tasty fruit, even by itself.

The smaller purple one could be a European plum (usually smaller than the Japanese plums).

These types of plums have different numbers of chromosomes and don't readily cross pollinate.

The Shiro is readily self fertile though, so even without another Japanese plum, it sets tons of fruit. The Shiro is also generally known as a good pollinator to other Japanese plums, so that's why I tend to think the purple one is a European plum. The European plum may be setting a small amount of fruit due to a combination of both maybe some tiny self pollination with itself or some uncommon crossing with the Shiro, to produce a small amount of fruit.

I bet either getting another European plum or grafting one onto the existing purple plum will significantly increase its fruiting.

Hope you get a lot of purple plums in the future Sonja!

Steve