I'll let someone with closer gardening conditions to yours opine on the sun/rain/soil but verticillium usually presents by infecting one part of the tree at a time. I've lost a few Cercis to vert. and in each case the first thing that I notice is about 20% of the tree (one large branch/section) has wilted and the rest looks fine. I cut that off, knowing that I am fighting a rearguard battle, and it proceeds through the rest of the tree. This looks more like too much sun to me but I'm in a very different climate so I will defer to others. The tree does look to be planted to deep, as you note.

the first pic does not show the root flare.. expose it ...

how did you amend the soil ... i never heard of silty clay ...

have you ever done a perk test ... how long does it take your soil to drain ...

when you do water.. how do you water ????

i would nto replant at this time of year.. but i would remove enough soil to the root flare ... if its really deep ... i would replant in fall at color leaf change ...

i think its a planting issue.. not a disease issue ... and i dont know why you treated for spider mites.. based on seeing webs ...

i have no clue what a bio pack is.. but presume its snake oil ...

see link for proper watering .. and planting for next fall

BTW .. i would not call that a young tree.. i would call it a very large transplant.. how did it come.. potted or burlap ... and did you do any root surgery ... was it leafed out at planting ... did you remove all the burlap ... etc ...

ken

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

I would also be reluctant to assess that as verticillium, although it could be early symptoms of a root rot. And if you suspect or know a plant has VW, the last thing you want to do is move it.......all that will do is spread the pathogen to other areas of your garden. And since it is nearly always fatal and a huge range of plants are susceptible, that is definitely NOT something you want to do!!

I would also agree it is planted too deeply and that plus excess sun may be causing the malformed, wilted leaves. Very few plants with very pale, yellow or gold foliage can tolerate full sun without scorching or other issues.

If it were growing here in my climate, I would not hesitate to move it now to a better draining and shadier spot (and at the proper depth!!) but I just can't speak to how much of an issue that could present doing so in your climate and location.

That is a tough one. I will say that my Rising Sun is also in full sun and has not had any problems. In fact I broke the rules and planted it during a hot July drought and it thrived . Watered it just the first year and have not touched it the last three years. Has gone through wet and dry periods without issue.

At this point, I think you just need to cross your fingers. You can't replant it until fall, considering that it is under serious stress and you don't want to encourage more leaf loss. I would not hold my breath. It is possible that something was wrong with the tree from the nursery. You can move away the mulch from the base of the tree to see if it was planted to deeply, but this is a pretty fast decline (within one year) for that.

I have not read much about specific varieties/cultivars redbud, but in general, redbuds are considered understory trees and should be planted in part sun or shade, regardless of what the tag says. I see a lot of dogwoods and redbuds planted in full sun down here and they always seem shriveled and stunted.

Like Ken suggested, can you remove soil down to the first set of roots, maybe an inch out from the trunk, to see if the roots are too deep?

Also, yes on the transplant, but do not do it until fall. You can sever 25% of its roots now by sending a shovel around a quarter of the tree at about 18-20 inches away from the trunk, to encourage feeder root growth interior to the 18 inches between now and fall (allows for a stronger root ball and better chance at survival for transplant.)

"I have not read much about specific varieties/cultivars redbud, but in
general, redbuds are considered understory trees and should be planted
in part sun or shade, regardless of what the tag says."

I have a Rising Sun in full sun, one in full (yet bright) shade, and two in part sun/part shade. The one in full sun has the better color by far although it does need more water. With Rising Sun it is a balancing act to give the tree enough sun to show it's full color but not so much that it wilts in the afternoon.

I have other varieties of Cercis as well as natives on my property and find that while they all benefit from some afternoon shade, the Rising Sun particularly needs a bit more sun to perform optimally.

OP- please dig down around the base of that tree and tell us what you find.

Please follow-up! It's educational for all of us.

Can't speak for a yellow leafed cultivar, but here redbuds are native and grow anywhere they want; full sun often.

And verticillium in present in the soil just about everywhere...

I am on my second Rising Sun Redbud. I planted one in late 2015, it flowered in 2016, then all the leaves wilted and went black. I decided to try again, this time I planted it in a mound, rather than in the wet clay. It is doing really well now. I think that cultivar is a bit finicky.

This is a picture of our rising sun redbud tree we just planted it last summer. Alus

Necessary

Hi - My RSRB looks much like yours in the picture at the moment - did you ever figure out how to help it?

Hi. Mine is also doing the same!

I am in Seattle, It’s probably been in the ground a year now. Sandy soil, root ball not buried, trying some fertilizer and more water. Cutting off the dead bits. thought it was a strong but late start to its bloom this spring but then never turned green.

Hi Tracy, I am also in Seattle and just bought my first Red Bud. So sad to see it looking wilted and sad even before I get it in the ground. Have you had any luck?

I've noticed that if there is a late freeze after they have budded out the leaves will just stop growing and stay whatever size they were when the cold hit. It took a good month of warmer temperatures for mine to start adding size to the leaves again. This happened to my largest, most exposed tree while the more protected ones didn't skip a beat. It was a little strange and did give me pause, but it's since recovered and has nice larger leaves now.

Redbuds are susceptible to canker.