The dogwood, Cornus 'Venus', has good resistance to diseases. This first year the roots are establishing and leaves are likely to show stress. Especially now as our temperatures suddenly swing from 60s into the 80s+. It is essentially water stress, as the roots are growing, not because the soil is too dry.
This is the time, though, to check on how the tree was planted, as there’s time to correct problems. Perhaps it will be easiest for you to communicate directly with the Metro Master Gardener Volunteers, as it could feel like a game of 20-questions via this online forum.
To stick with me, though, provide photos of the whole tree, and the surrounding area, also specifically the trunk at soil level. We try to judge if the tree is planted too deep, which is a common error. (ISA planting a tree)
Then describe the planting process: was burlap removed, was root ball loosened and any circular roots pruned, any amendments added to the planting hole? What was in this location before? What is the sun exposure? How big a circle of vegetation-free mulch is over the roots? Is the winter drainage in this area fairly good, or does water pool?
Our soil is naturally acidic so don’t worry about adding coffee grounds. And the clover won’t give the tree nitrogen, but you don’t want to fertilize a stressed tree anyhow. I don’t have the same tree to look at, but I think the “residue” on the leaf undersides is normal. Does almost every leaf have it?

Thanks,  I'll stick with you.  I have attached 3 more images. Planting process:  burlap was removed and root ball loosened.  Did not see any circular roots.  Soil was amended with G&B Organics "Harvest supreme premium soil amendment with 15% chicken manure" in the hole and around the planting.    In this location before was an elderly azalea which did not make it through last summers heat.  The tree is planted about a foot and a half in front of where the main stem and root of the azalea was, which is just behind the oregon grape in the picture.  The sun exposure is part sun to full sun (somewhat seasonal) .  You can see the mulch circle in the picture, now I am thinking maybe we should mulch more.? We have been using chip drop mulch but happy to get something else to help my dogwood baby.  Winter drainage is good.  The azaleas on either side are looking really good.

Thanks again.  Barbara Walden   <personal data hidden>

The photos didn’t come through yet.
My neighbor rigged her lightweight patio umbrella to the west of her baby dogwood last summer for the hottest days. If you’re in a wind-free area that might be good for these first few 90 degree days. Stay back far enough for good airflow though. No creating an oven by getting any shade cover close to it. 
Your tree is going to spend the first two years growing roots and you’ll see it in the foliage and growth rate.
Soil amendment is not recommended, as you want the roots to move beyond the planting hole into the landscape. How much amendment did you use (just a guess at % or amount)?
Arborist wood chips are a great mulch on top of the soil. The varied sizes allow water and air movement better then some other mulch materials.
I suspect the advice will be patience, but I’ll wait to see those pictures. 

hi..  I am resending pictures.  Did not use much soil amendment, but seems like this might be part of the issue.  The tree is so far not actually dropping leaves so this is encouraging.

Watering:  I was going to water the dogwood the same way I have been told to water our new Douglas fir and new Willamette Ponderosa--  3-   5 gallon buckets once a week.  Will be starting this regimen this week.  Shall I do it the same way for the dogwood?  

Carefully remove soil along the trunk and find the “root flare”. This slide show from Clemson U. Has great photos of what I’m talking about.
You might need to replant the tree higher, depending on what you find. I hope not.
I don’t think the amendments sound like a reason alone to replant it.
You do want to get a bigger area of no weeds or grass around the tree. Use good deep mulch, not bark. I see some bare soil there right now. The only real way to know if tree is getting enough water is to check the root area. Pull back mulch and use your finger, for instance.
What can happen is that people water the soil around the roots, but water doesn’t move into that nursery-soil around the roots. Other times the nursery root ball gets totally waterlogged and owners just keep watering because they are checking soil outside of the root ball.
Water doesn’t move well between soil that is different textures, and roots generally follow the water. So that interface between nursery roots and native soil is important.
Oh, another thing to check and report to me is how it holds up with a gentle “wiggle test”. Take the tree at chest high and gently try to rock it. If roots are grabbing, it shouldn’t move much at the soil line. I had one person report they touched the tree and it just came up. But in that instance, the burlap was still on it!