From looking at the Google Images, this is a walnut tree. I think the black walnut tree has slightly smaller leaves than the regular walnut? But we do not have walnut tree at our property. At our property, we do have two or three large black walnut trees. Their seedlings do cause problems...

We don't have EAB here yet, but we do have what are called lilac/ash borers. We have Phaenops gentilis, Chrysophana placida and Agrilus cyanescens. Many non native trees do need help here, but you don't know specifically what to add without a soil test. Unfortunately, they are not free here, but the cost is nominal, maybe $25-30 depending on what you're testing for. I would take soil samples from areas where you haven't fertilized. I just don't see wasting money on additives until you know what's missing from your soil, or what nutrients you already have enough of. I would also be extremely careful with fertilizing right now as we are in severe drought status. If you feel like you need to fertilize before you have soil test results, maybe do half strength. Any problems you're seeing now are most likely drought related as we've had virtually no rain, horrific winds and weeks in the high 90 - 100+ degree temps. We have a 50% chance of rain this weekend, which would certainly help. We've had roughly 4.5" of precip. so far this year. Your soil ph is most likely in the 7 range, as mine is 7.9. I have a Patmore ash, fraxinus pennsylvanica 'Patmore' planted 4-5 years ago and I've not ever fertilized it. It's doing fine. Your ash looks good to me. The native tree choices here are limited which is why we bring in non-natives. FWIW I don't have 10 years experience, just 5, but have planted and killed enough trees that maybe I'm not a newbie anymore, lol. I'm still learning and will be for life. This is a tough place to learn the ropes, but you're doing great. I love your yard! Barb

Cork tree - Phellodendron amurense. It is pretty common in MN as a street tree and is actually becoming invasive in some areas.

Hi Goodplantz, was hoping to see a reply, as I would like to know the differences also. I am not very familiar with Ash trees in our area. I do know the Shamel has been hit with a bug in some areas of the valley. There are people on the Dave's Garden website, Southwestern Gardening Forum that have knowledge on ash trees.