Following. Mine exhibited the same both this summer and the last. 3 years in ground, properly planted, other stone fruit close by are fine.

How far from the center of the tree are you getting the deep watering out to? Sometimes the roots grow far out when there's water available.

Flood irrigation, so the entire yard gets 8" of water every two weeks for the warm 7-8 months out of the year. So in my yard this is scores of feet out from the tree.

I put the hose at the dripline.

I wonder if it's just a summer/heat thing since both of you are getting it at the same time. My 2yr old anna apple tree looks pretty bad from the latest string of heat waves but is coming out of it with some new foliage. My Beverly Hills apple tree handled it like a champ and is greener than ever.

I'm looking at some plum trees for my next tree purchase so I'm wondering if they grow better with some shade in the afternoon.

My thought as well Landyaz, the only thing that gives me pause is that of the 12 stone fruit, 8 apple and 6 pear trees in my yard, the Santa Rosa is the only one exhibiting this sort of burn. They all have the same habitat, feeding and watering schedules. But I definitely think it's heat related, as it happened last summer at the same time, and came out the other side fine. So I'm only a little concerned.

Hmmm. "They" should not sell themas appropriate for Phoenix then! Phoo

Not only the heat stress, but this spring's winds took the baby fruit off of all of my fruit trees. Very little left. I'd say not worth watering for, but then the trees would die.

"They" should not sell themas appropriate for Phoenix then!

Silly Girl ernie! ;-) If "they" only sell what will grow here, they'd go bankrupt.

In my New Western Garden Book, from Sunset (where I am in zone 13), the only zone 13 plums are Damson [Pollination: self fetile (same as Santa Rosa); Fruit: is small, purple or blue black, green fleshed, very tart; Remarks: makes fine jam and jelly; Strains of this vaiety sold as "French Damson", "Shropshire"]

and Inca [Pollination: 'Beauty', 'Wickson', Kelsey', 'Santa Rosa', 'Satsuma'; Fruit: Medium-sized, yellow-skinned, yellow fleshed fruit. Firm fleshed. Late. Remarks: Good home variety. Fruit holds well. Discarded commercially. Very low chilling requirement.]

It's odd to me that Inca, ok for zone 13, needs a zone 14-23 tree to pollinate it. There are no zone 14's in Arizona. Some zone 12's, Florence, Wickenburg, maybe Morristown, Wittman, hard to tell on their map. All the pollinator varieties are okay in zone 12. Maybe you can get an Inca to help the Santa Rosa. Good luck y'all.

Next year I will resume the light shading I did before.

I think you mentioned an 8" depth. I think you need to put the soaker hose on it and be sure to get to a depth of 2 feet. Also in my Master gardener notes I read to place them where they are not exposed to the afternoon harsh sun as the will suffer from sunburn. Hope this helps!