Shumard Red Oak stressed
We have a Shumard Red Oak that is almost 3 years old. We purchased it then, that is. It was not a huge tree but it was healthy. Enter the DROUGHT, now going into it's 4th season.
This Spring while it grew new leaves they are very light green but the veins are a deeper green. The ends of the leaves are now looking burned. We have a few places where the trunk has split open (stress or growth?). I have put tree paint on the openings b/c I don't want bugs to attack it. I have checked for moisture with my houseplant water meter and it is indicating it to be moist. The stem portion of the meter is 7.5" long and I am able to insert it all the way in. I use a soaker hose and water for about an hour at a time 3-4 days/week in the hot months and back that off to 1-2 days/week in the cooler months. We have recently had some rain up to 1" so that helps in the watering department. I already know one thing I need to remedy. My husband put the mulch all the way up to the trunk instead of leaving it mulch free. All our other plants and trees are fine. I even see other Shumards in the neighborhood that look nice and green. Granted they are more mature but still. The trunk and branches are green and pliable.
We have very alkaline soil. In fact we have a huge table of limestone running across our yard. It has been suggested it may need iron. Thoughts?
We don't use pesticides in the yard so I know we haven't poisoned it. Our yard is in a natural state. We don't water it mostly b/c of the high cost of watering a 1/3 acre lot ($300+/mo) so we just water beds and trees.
I have included a photo (I have more but seem to only be able to upload one( so hopefully I can get some good feedback on what to do for my tree. Any and all help is appreciated. Thanks.