Since the tree is not right on top of them the shade won't be the problem in this instance, they are drying out or getting root rot instead. Or you have pests like mites. As far as general soil conditions are concerned you are likely to be able to improve plant response markedly by applying and maintaining a substantial mulch. Or course, this won't correct any severe issues with wetness or dryness inside the root-balls, or bugs or blights on the foliage.

This cultivar is extra prone to root rot, problems with part of a hedge dying out are asked about on the web frequently. Otherwise much stock planted comes in field soil root-balls that may be allowed to dry out between the grower's field and the final planting site, fail to re-moisten after planting.

If you suspect there is a soil moisture issue poke around inside the original root-balls to see what the situation may be.

on this pic.. i dont see any dying... how about a better pic of the last 4 or so ...

but lets think outside your box ... the box being.. BTW.. your problem ...

why do you insist on straight down the fence line ... do you really use that corner for bocci of some such ...

if you measure out say.. ten feet from the corner ... and made a gentle curve .... you could now plant them out from right under the canopy of the tree ...mabe put a garden shed back there ... and then hide that with the arbs .... many of us.. would suggest.. that much less lawn to mow ... lol ...

as with bboy.. i think your problem is the tree.. outcompeting the transplants for water ... what might be good enough water for the rest.. just isnt doing it for the ones struggling ... so lets try to move out from the tree.. and perfect watering for these in particular.. like you did for the rest ....

you didnt mention where you are ... any drought this year ... or torrential rains.. etc ...

it is clearly a watering issue.. for if it was a stock issue.. it would NOT be the last 3 or 4 that would be problematic ...

and if watering is the issue.. then no replacement of a different sort.. is going to thrive either ...

BTW ... how id you plant them ... and if you threw fert in the hole... then you probably have increased tree root competition ....

and if you bought them at bigboxstore.. i hope you are returning them under warranty

more info.. better pix... and if you dig one up.. take a pic of the roots ... maybe that will tell us something ...

ken

I forgot to mention that we are in central Pennsylvania, about an hour directly north of Harrisburg. We have had what seems like a fairly average summer, possibly a little dryer than normal. When we have a dry spell I do go out and water the shrubs.

Here are few more pictures taken last night. The original that I posted was from right after the shrubs were planted.

Close up of the dying arb. - http://i.imgbox.com/2OyAmbIA.jpg

rear of the arbs., note the tree coverage. - http://i.imgbox.com/3TPLIqjB.jpg

Two more pictures showing the tree coverage and shrubs.

http://i.imgbox.com/tFiUHZgv.jpg
http://i.imgbox.com/iXUjxdB0.jpg

You will notice only one very browned arb, the two directly next to this one have been replaced in the last 4-6 weeks as they were in the same state. Lowes offered a 1 year warranty so I was credited for the purchased amount.

My thought about bugs is that it is unlikely as the three shrubs I have had the problem with are all right next to each other. I could be wrong in this assumption.

About applying a mulch, noted and I plan to take care of this immediately.

I am happy with the layout of my yard/fence line and I do not require a additional shed as we have a sizable shed/single horse barn already for storage.

I did not put fertilizer in the holes when planting.

The ground in that area is extremely hard and compacted (compared to just a few feet over). Would it be beneficial to till up all of the ground in the general area down to maybe 12" or so? Will this help with my problem at all?

When I replace the dying arb, should I break up the compacted soil (clay) that the root ball comes from the store in?

Thank you again for all of your help.

I think there is enough light there. It does not look like deep shade. You need to make sure they are kept well watered until ground freeze. Use slow watering system like drip or soaker hoses. Insert your index finger into the soil at the root zone of each tree. It should appear moist but not wet. Water as needed. The ones near the trees will probably need more frequent watering. Slight drying between watering is okay. Too wet and the roots will rot.

Would you suggest replacing the dead arb now or waiting until spring? It has been getting close to freezing at night here in Central PA. My gut tells me to wait but I just wanted to see what other people are thinking.

Thanks again for all of your help.

You should check you local code laws with your city. In my city you can cut back to the property line all foliage growing over your property line. You don't need your neighbors approval. It's the same as him parking his car in your yard but in this case it's his tree.

Too much shade under the trees for those 3-4 and they won't be competitive with those free of shade and grown in the sun.

Ken's idea of getting them out from under the canopy with a free flow design is the way to go.

Wait till Spring to replant. Nursery stock fresh then. Don't buy the old stock laying around all Summer for Fall planting.

Dave

Wait for a year...u just planted it 6 months ago...it could be transplant shock