I have a santa rosa plum tree that is about 16 ft high and in very good shape. It’s at least 6 years old or more.
A couple of years ago it had tons of fruit formed but due to the black knot I’ve cut a lot of branches down. Then the tree grew up even bigger and stronger and it looks like I got rid of the black knot (used some medicine for it too).
Now the past two years the tree makes lots of flowers but almost none of them turn into fruit.
Last year it made one plum (that the squirrels ate it). I blamed it last year on a late frost.
This year the flowers just dropped and I do not see many (if any) fruit forming. The weather has been warmer then usual in north east NJ and no frost. We even had temps in the 90s in April.
It’s also right next to another plum tree (forgot the type) that was supposed to use the santa rosa for polarization.
Usually I graft end of march to the first part of april dependent on the weather. I created several franken trees from freeloaders, so it’s a lot of varieties. I reduced the amount of stone fruit trees I had in favor of franken trees because of the amount of spraying they need on the east coast.
My Santa Rosa is 10 yrs old. I keep it pruned to 10 ft. Some years it fruits heavy and requires thinning. One year it only produced about 10 fruit. Weather is sometimes cool with less active pollinators during flowering and that can reduce number of fruit. This winter was warms and suddenly cold and that damaged apricot flower buds. Plum flowering is almost completed and I don’t know yet how much fruit there will be.
Yes, Santa Rosa can be a very poor setter in many east coast climates. I top worked mine to Weeping Santa Rosa which sets fine. Other great plums for me are Satsuma, Lavina, Laroda (a late Santa Rosa type), Purple Heart, Shiro, etc.
My Santa Rosa had plums year 3. Year 4 & 5 nothing. Need to graft over to something else. My chickasaw plums right next to it are doing great and produce every yes if I can keep the curcullio off them. BTW anyone know if I can graft the Chicksaw(Guthrie) onto the Santa Rosa?
My Japanese plums are blooming now. Daytime highs around 50, lows around 40. Rain every day, damp out there. That’s not unusual around here, although things are a couple of weeks later this year.
Santa Rosa probably doesn’t like that. This is very different weather than California.
Nadia cherry plum, and Shiro seem entirely unfazed, and are probably my most reliable stone fruit here. Splash pluot does well too.
Flavor Supreme and Emerald Drop have still yet to fruit after many years, even when others on the same tree do.
I have a Santa Rosa that produces only a few plums most years but occasionally has a decent crop. What seems to be happening in a good year is that the weather has to warm up faster than usual for our climate at and following bloom time. This only happens when we have a cool early spring (delaying flowering) that changes to warmer (and dryer) weather right after flowering. I have Beauty and Shiro plums on the same tree, and they produce usually excessive crops practically every year. I don’t know if similar conditions have the same effect in eastern North America.
I have a weeping Santa Rosa. It’s 3 years in the ground so it’s in its 5th or 6th leaf.
Last year was the first year it held fruit, but only about 2 dozen.
Poor flowering (warm winter) and a March freeze removed any chance for fruit this year.
Strangely it didn’t put on any new branch growth this year. It’s in a 36" fire ring so it could be root bound, though it’s open to the ground. Soil is about 12 inches above grade.
Anyway I got it for it’s shape and it’s mentioned in so, so many Japanese plums descriptions as pollinator.
I did plant a standard SR whip as part of an espalier so hopefully it too helped with pollinating other trees.
Lots of spot this year. It rubs off but it’s a butt ugly.
I wonder is it better to plant the weeping Santa Rosa in container first. My Santa Rosa has fruit but it’s a graft and the Shiro is growing much bigger. But Shiro had nothing this year.
Plums are problem free here, at least rats, mice, squirrels don’t touch them unlike figs.
I am not grafting to my weeping SR since whatever I graft won’t be weeping. It will mess up the form of the tree…which is the main reason I bought the tree…
So after commenting on getting no new beach growth last year from my Weeping Santa Rosa, I’m happy to say I’m getting many new weeping branches this year.
It may be hard to see, but the lighter colored leaves are the new growth. Some reaching 3 feet now.
Fertilized late winter may have done the trick.
Still a very light producer as I maay have 15-20 fruit set.
Might try spaying it with Monopotassium phosphate “MKP” the active ingredient in Gatorade. Also withhold N, but not Potassium.
The dope growers are big advocates. I suspect that Santa Rosa not producing good fruit loads Back East has something to do with the greater fertility of eastern soils. An MkP spray every 3-4 weeks during the summer might help.
It’s hot stuff though. A quarter teaspoon or less per half-gallon is fine.
