Couldn't attach the photos for some reason. Here they are:

Sounds like the balls themselves have not been kept moist. I'd trickle some water there for a spell. A wetting agent if you really want to go nuts, but probably not needed.

be nice to know where you are ....

how about you take a hand trowel .. and dig some holes around those.. AND FIND OUT WHAT THE SOILS LIKE ... and now that its oct.. maybe dig the end one out and FIND OUT ...

is that an engineered drip ;line.. or the common old recycled rubber product ... the latter is known for not hold pressure along a long run ... and not providing water at the far end.. as it might closer.. and it is not engineered for anything but level ground ...

you need some real info.. so we can answer the issue.. rather than us all guessing

ken

Thanks, both of you. Ken, you're right, I do need some real info. I guess the problem is I don't know enough to know what I don't know.

Like I said, I'm in Zone 7 (southern TN). The soaker hose is a nylon hose, not a rubber one - a landscaper told me they were better, and I'm hoping he was right. I've checked multiple times while it's running and water has been coming out (what appears to be) evenly along the length of the run.

I'm fine with digging up some soil, but I really don't know what I'd be looking for. Like I said, the soil around the root ball is damp, but the root ball itself appears to be dry. I'm guessing I'll find the same once I dig in, but I don't know. Perhaps more importantly, I don't know if what I'll find now is any reflection of the conditions that actually caused this problem.

Tom, I'll try giving the root balls some water directly and see if that does anything. Any idea as to how long it should take to see some results from that? I'd hate to do that every few days for a couple weeks, only to find I was indeed actually drowning them.

Usually when i see leaves turning golden then turns brown then gray on my arborvitaes, it means sun burn. im in NJ zone 7a & we had lots of 90 degree days with very little rain this past summer, that i have to not only heavily water them, but also give them a shower from top to bottom every single day manually. i have 40 emerald arborvitaes which are not prone to burning & 44 american pillar arborvitaes, which still burn a little under a heatwave even with the watering & shower that i did.

I guess maybe a better question is this: I've gotten the feeling that these things are indeed getting too much water. Is the type of browning seen in the photos consistent with that? I really have no idea what that looks like, but I know it's possible.

Any thoughts (at all) are definitely still welcome, though. High temps are finally supposed to be below 90 again this weekend, so hopefully they won't be in need of quite as much water now.

ive had my arborvitaes for 3 years now & i only see yellowing in the summer months, when theres a heatwave & i dont water much. i got rid of the soaker hose & water them manually, bec i want to see how much water gets to them. its a lot of work, so not recommended, but this year, its a relief, verylittle burning compared to last year.

really don't know what I'd be looking for.

==>>> you will be analyzing the soil ... its either too wet.. or too dry ...

if its neither.. then water is not the issue ...

can we presume that the middle one.. is not involved with a dog???

ken

Too dry - foliage damage is sun burn. Check original root-balls for dryness.

Would have done better if mulched after planting.

Thanks, all. Especially Tom - exact info I was looking for (even if I did a poor job of explaining it). Soaking the root balls is definitely something I can do. I had been running the soaker hose ~12-18" behind (slightly uphill from) the bushes, in order to encourage some root growth outside of the root ball, in the (possibly mistaken) belief that the water would also flow/soak into the rootball. Looks like that wasn't happening.

I guess the healthier ones (not pictured) were in good enough shape to grow roots outside of their root ball, while these were just trying to survive, and weren't strong enough to extend their roots.

I've got some good root stimulator - should I use it, or do I risk causing damage? Any other fertilizer/products I should try? I've got some superthrive that I used in early summer, as well.

Ken, no, no dog on that middle one. It was the roughest of all of them from day 1, and lost some lower foliage last winter. Still hasn't really recovered.

While I've got the experts here, I guess I could ask one other question. The other 20 that I have are in great shape - full, green, growing steadily. A few are, in fact, too full - they have 2 leaders. I've read that arborvitaes with 2 leaders almost always end up splitting, and should (/can safely) be pruned to only have 1. Is this true? Is it necessary/encouraged/safe/whatever? I assume this should be done in the spring, not the fall?

Thanks again for all the info. I'm going to give the rough ones more water right now.

Have not read postings but I've always found it frustrating that half the people say too much while the other half say too little moisture. That is why the only way to know is by sticking your finger into soil around base of plant. If OK then you can go on w/other possibilities. Looks dry to me but I didn't stick my finger in there.

i agree bossy... dig some holes and find out .. ken

Bobert18, about your multi leader question, i dont think you can prune an emerald arborvitae to become a single leader, bec its really a multi leader tree. This is assuming that what you have are emerald arbs. Thats my regret buying so many of this tree before learning about the problem, bec its a lot of work during a snowstorm, specially if its a wet snow, its impossible to brush off. you just hope they go back in one shape after the ice melts.

let me add that, my quest for a 1 leader evergreen led me to this new arborvitae called American pillar arb. i transplanted all 40 emerald arbs after 1 year in 2014 & replaced all with the pillars. i clipped, cut, pruned & dig out all suckers & competing leaders after 1 year & now i end up with what looks to me like young bamboo stalks, very thin, narrow & very tall single leader arborvitaes. i posted this pict in gardenweb, but here it is again, 2 years growing in NJ. three 7 feet emeralds are still at the top.