What plum variety do we have, and why no yield?

[kenc]

We planted what was supposedly a Santa Rosa plum maybe 6 or 7 years ago, Despite being "self fruitful", it yielded very little, never more than 11 plums, usually 5 or 6. The tree is beautiful, large and strong, couldn't be healthier.

One mistake which was made, was planting it with the graft below ground, we didn't know any different at the time. This has resulted in little sprigs popping up all over the place. I don't know if this is relevant? About 4 years ago, we dug the dirt away and exposed it, although I'm sure that's of no use.

We thought maybe another variety of plum planted close by would help, so we planted a Satsuma plum two years ago about 15 feet away. This year, the Satsuma has dozens and dozens of plums despite us culling maybe 90% of them to prevent the branches getting overloaded. Without this it would've had hundreds.

The "Santa Rosa". Two plums!

Looking at the plums, we don't think it is a Santa Rosa. I've included pics.

Does anyone know which variety of plum it actually is? And why we get no yield at all?
We are in the San Francisco south bay area.

Thanks (hopefully!)

[imafan26]

I don't grow plums because they are hard to do in my zone. However, I did look up your zone. The satsuma plum range is zone 6-10, Santa Rosa plum is zone 5-9 and requires a minimum 400 chilling hours. Unless you live in a micro climate that is cooler, San Francisco is zone 10a-10b. It may explain why the Satsuma does better than the Santa Rosa.

In my zone only low chill stone fruit can produce fruit. Even so, they still require minimum chilling hours so it is not unusual for those fruit to bear on alternate years because it depends on if it is an El Nino or La Nina year. This is the reality of living in a marginal zone. Stone fruit here has the best chance of fruiting at elevations over 1000 ft.

[kenc]

Thanks for the reply. Another issue that I had no idea about "chilling hours".
Who would have thought that it wasn't just a matter of throwing it in the ground and walking away....LOL.
Our mystery plum gets covered in flowers , but never much fruit, it also flowers about a month earlier than the satsuma if that helps any to identify it.
The only other similar tree nearby is our Plumcot which yields tons too.

[Vanisle_BC]

In my (local) experience there are plum years and almost-no-plum years. Whether this has to do with 'chilling' I don't know. This is a no-plum year. Even the roadside wild yellow ones have no fruit.

In good years our very old Santa Rosa has produced 50lb of fruit; in some 'between' years just about zilch. The tree is now almost dead, whole branches having progressively died off. Multiple vigorous wild suckers have subsequently come up from the root but, again, they have no fruit this year.

I love the flavor of Santa Rosa but to me the skin is bitter and I peel them. My wife likes tangy things. She eats them whole. Chopped (and skinned of course!) they make a mouth-watering flan - Or in a dish of home made ice cream, drizzled with your favorite liqueur - heaven.

[imafan26]

Besides chilling hours, the weather plays a large part of it. For us, this is a bad lychee year, not only because of the crazy hot and cold periods during the winter months, but also because of the December rains and cold weather during flowering. If it rains at the wrong time, it ruins the flowers, there is more fungal diseases and less fruit. Chilling is needed to induce flowering, but you don't want it cold after it flowers. The last three years have also been drought years so, the trees have been suffering from that stress for a long time as well.

https://www.davewilson.com/home-garden/ ... quirement/

[kenc]

Thanks for all of the information everyone.

It is strange though to me, that our Plumcot which has very little "cot" and a lot of "plum" yielded well, our Satsuma is yielding out of control, yet the mystery plum had two plums on it, and the damn squirrels got one of those. Perhaps it's just the timing of the flowering? Mystery plum did flower earlier than the Satsuma by a month, and by a week or so on the Plumcot.

Is there not enough evidence from the pictures of the outside and inside of the fruit to identify our plum? Is it really a Santa Rosa? It doesn't look like the SR plums I see online.

Do we need to do anything more to the base of this tree? I mentioned that we dug the graft out of the ground several years ago, but do we need to dig out more of the soil or is there enough "flare" (A new issue I learned today)?

[Vanisle_BC]

From memory because we don't have any, I'd say your plum's inside looks much like Santa Rosa, but the outer skin does not. It would be more 'plum colored' (like the inside) and less yellow/green.

I don't know what a plumcot is?

[kenc]

A plumcot is a plum apricot hybrid. Although, ours seems like a plum with very little apricot in it. I believe they're also called pluot, apriplum and a bunch of trade names.