You may be having a pollination issue. Do you have an adequate pollinator? Are your trees self fertile? My plum trees took about 3 or 4 years to produce fruit.

There is a possibility that you may still have fruit develop if the blossoms turned brown after they bloomed but the base of the buds didn't fall off. Santa Rosa should be self-pollenizing. Plums are kind of touchy about setting fruit by nature. You may not get fruit every year, especially on certain varieties. Santa Rosa is typically pretty reliable.

Did you have rain during bloom? That could affect fruit set. Any other signs that the browned blossoms may be due to a disease like brown rot?

Carolyn, Santa Rosa is not reliable at all for me, it depends a lot on the climate. It is also not reliably self-fertile.

Probably the most likely thing is the tree is not old enough. For me Santa Rosa took 4-5 years before it set - it was a slow starter in my climate. Shiro was much quicker to set and set more reliably.

Scott

Interesting how climate affects pollination (for pears, too, I guess). Santa Rosa is the classic self-fertile pollenizer here and often produces when other varieties do not. I have two trees and have had years when one sets much better than the other, however. Even commercial growers here in one of the most favorable climates for Japanese plums must take into account the fickleness of plum pollination.

I have found that the rootstock can also affect how young plums and Pluots produce. Those on Citation tend to produce younger.

I purchase my trees from Lowes and I use well water to water my plants and trees every other day, because of the heat. On one of my trees all the flowers have drop off and not fruit, and the Santa Rosa is still flowering with no fruit set.

I am still waiting to see if the flower will leave fruit and not fall off. So far nothing!

I have a Bruce and Burbank, same age planted closely.
Both produced flowers at the same time, yet the Bruce's turned brown and nothing. The Burbank on the other hand has lots of itty bitty fruit YAY. Still need to find a Santa Rosa for my Satsuma.