Marble sized is a reasonable time for thinning apples or pears IMO.
Be careful with peaches, don't thin them too soon. Peach trees will do quite a bit of self-thinning and will choose which fruits to drop themselves. You can see this by noticing that some of the peaches are growing larger while others lag behind. The ones that aren't growing, or growing very slowly, are going to be dropped. So you want to wait until the tree shows you which ones it is going to keep. You can then thin out all the small ones, and then decide which of the keepers to thin out or mature. This would be about when they reach the size of a quarter (25-cent piece).

Thanks!

I'm new to all of this and I do remember my (couple of year old) peach trees droping friut on their own last year, but I didn't notice anything happening with the apples or pears (both are mature trees). Of course the deer could have just done the clean up work for me! (the peaches were caged).

Another thining question if possible: what is good time to thin apricots?

Thanks,

Katyajini

Katy:

The time to thin apricots is as soon as you can differentiate between the fat, fast-growing fruits and those that are growing slowly or not at all. I don't wait for the "natural" fruit drop, but remove all the smaller fruits well before this would occur. I know they are going to fall anyway, and see no reason to leave them on the trees. Of course, there is a certain saving of labor by waiting for the drop, but I don't want to leave apricots with no future when I am out there thinning anyway.

How many and how close you leave the larger, healthy fruits is a judgment call. I always remove twinned fruits opposite from one another, and of course, all truly "twinned" fruits growing from the same stem (this occurs more frequently on peaches). But whether you leave healthy fruits right next to one another, or try to space them at 2 inches or 4 inches apart will have a significant influence on their final size. If you are satisfied with smaller 'cots, leave them close, but if you want big, fat and sassy apricots, thin them to at least 2 inches apart.

Don Yellman, Great Falls, VA

Thank you jellyman!

The time is pretty much now.

Katyajini