Leaving burlap on and planting in amended backfill both mistakes. Next time plant in same soil that came out of hole, without modification. If you want to plant in different soil plant in layer of that placed over top of existing soil or excavate and replace existing soil over a large area. Small pockets of one soil surrounding by another may have problems with how water moves into and out of the smaller area.

Poke around in the original soil balls to see if these have dried out or are sodden. Yews must have good drainage and are prone to root rot where drainage is not good.

There is another unpleasant possibility--the black vine weevil, very common in many plants but its favorite is the yew, Taxus capitata. I once planted a hedge of yews and almost half of them started to turn brown, despite the best care. I was mystified. I called the nursery where I bought them and they told me to bring in some affected branches. It was the black vine weevil.

There is a spray for it, which I used, tho I almost never spray anything. Some of the plants were too far gone but I saved some others and also the ones not yet affected. Plants grown in huge wholesale nurseries seem to be particularly affected. Many ornamentals can get this tho I've never seen it before or since.

I'd be very suspicious that you might have black vine weevils, as they are newly planted shrubs. Google "black vine weevil" for good info about this pest and suggestions for control.

'Capitata' is a cultivar of Japanese yew, and not a species of yew "Taxus capitata". How did the chewing of the branches which was presumably the basis for deciding weevils (black vine weevil is not the only pest species in gardens) were present? Were numbers of grubs also found by uncovering roots, or was it merely assumed that the browning of the tops was due to larvae feeding on the roots?

I am well aware of the fact that T. capitata is horticultural shorthand--sorry if you were confused.

The nursery from which I bought the shrubs diagnosed the problem and replaced all the dead/dying plants, to the tune of hundreds of dollars. I doubt they would have done that without clear evidence of the black vine weevil, an insect I had never heard of before but with which the nursery business is all too familiar, as they explained to me.

Lastly, the Ortho spray I used cured the problem on the remaining shrubs, evidence that the weevil was indeed the problem. If it had not been the weevil, the spray would have had no effect.

hmm. THe nursery where I bought it from is the one who suggested leaving on the burlap and adding compost. And it is the largest most well known nursery in the area.
I'll try to dig a bit and see what the roots look like, but we got more rain yesterday so if it's due to too much water this isn't helping.

My long-established yew hedge has several plants with browning branches close to the ground. I see no evidence of spider mites (which we've had in the past). The branches seem to be dying from the tips, inward. Is this a fungus? I'm 30 miles north of Chicago near Lake Michigan and we've had a wet spring, followed by more rain.

ginny12 -- How do you diagnose black vine weevil? I don't see any insects.

Thanks, ginny12. I did Google and unfortunately discovered what I believe is the problem. There was info on yews being poisoned by old apple tree roots decaying in the soil. We removed non-scab-resistant crabapples from the area eight years ago.

I'm calling the Chicago Botanical Garden today, but if it is the roots...looks like we'll lose the hedge. RATS!