Are they both on the same rootstock. Are they in ground/container. It would be normal for the thined tree to grow larger.

Satsumas typically take 3-5 years before the fruit quality gets good, even then there can be variation from tree to tree and year to year. I have 3 mature 15+ year old unkown varieties of Satsuma trees (2 appear to be the same, 1 has a different skin texture). It seems each year a different one produces the best fruit which I attribute to differing weather conditions, etc.

I have two Satsumas planted in-ground side-by-side and each has been fruiting now for a number of years. This year neither tree made many fruit...maybe 12-20 fruit apiece. One tree is in a considerably drier root zone as it's slight;y higher elevation and it's closer to a pine tree it may compete with for moisture. The drier tree's fruit were small to normal size and very tasty. The wetter tree made HUGE fruit that were quite bland. I personally think Satsumas taste better before they are dead ripe since they still have a little tartness left.

John, I had very low yield on 2 of my 3 mature Satsuma, around a couple of dozen on one, and only a handful on the other low yield tree, the 3rd tree has hundreds, though the flavor is bland on that one this year. I am about 100 miles inland on the Louisiana gulf coast, and have heard many people in the area had poor crops this year.

I would fruit poorly if I had been hit with 180 mile per hour winds while being drenched. with 53 inches of rain.

They are both in 16 gallon container since I can’t plant them on the ground because of gopher problem. They both have the same rootstock, I don’t know what kind though. Last year’s crop were of the same size & are both good. I didn’t thin them last year.

As far as my 2nd question do mandarins continue to sweeten even after changing color(wintertime=less heat) or do they just decrease in tartness due to cold?