quit pulling it apart to look inside .. that is normal interior ...

is this one in more shade.. or get less water due to other trees???

give us a pic of all of them together.. so we can see the whole ...

you are lucky its on the end.. usually the problem child is in the middle.. lol .. think about that.. lol.. its the story of life...

ken

All are in full sun The questionable one is on the far left and it was only pulled apart to get a pic. From a distance, all looks well. I also included one more pic from the side where damage is more apparent

overall they look pretty good ...

looks like someone kicked a ball into it ... i would ignore it ... it will fill in ... in tree time ...

as i said.. interior yellowing.. and then browning is normal.. as the canopy extends.. and the inner stuff ends up in total shade ...

the lawn looks like it is moving toward drought.. so a little drink of water never hurt ... put the hose on trickle.. and water each tree for as long as it take.. in your soil .. to get water down into the root zone ...

personally i dont believe in feeding trees.. and both lawns look weed free.. so i suspect fert is also provided to the lawn.. and the trees will get everything they need.. and more.. if in fact.. they need any such ...

i just dont think there is anything to fix ... so dont create more problems trying to fix that which not need be fixed ...

its not hard.. to figure out what your goal was.. with that planting.. lol ..

ken