Are they turning in isolated spots or diffusely all over? I ask because nearly overnight, one of my two well-established ones (both also subject to the same conditions), had a change in leaf color, in one particular section, to a dullish brown that, at a distance, looked a little fuzzy. I also noticed last weekend at a highly-regarded nursery that some of theirs are turning red in sections, which seems a little early in the season.

not sure, i'll have to look again tommorrow. too dark now. i think it was all over though. not every leaf, just every area.

check the root zone for proper water at a proper depth ...

i presume that since you planted 6 .. they are well spaced out... across distance.. soils can differ widely ... perhaps you THINK they are all getting the same water... and maybe they are at the surface ... but maybe these two are not getting it at the root zone ... insert hand trowel or your finger at 3 to 6 inches to see if its hot or dry down near the roots.. if so .. water them more ...

good luck

ken

thanks, i will try that although they are right in a row so they will become a privacy hedge. it seems to be the end leaves and the top leaves. i'm wondering if they could be getting scorched from the sun. they do get full sun all day. also, it seems to be starting on a third bush. any chance this is some kind of disease?

the only disease is lack of water ....

you are responsible for all water this year.. and browning tissue means they arent getting enough water.. deep enough into the root zone ....

drag out the hose... put it on a trickle.. and leave it at the base of each tree for 6 to 8 hours ....

take a hand trowel .. and on one of the worst looking plants.. dig a small hole 6 to 12 inches deep and see if it is cool and moist in there.. if not.. lack of water is your only problem .... do not let them dry for the rest of this season .. and in drought next year ...

BB are a full sun plant.. they do not brown in full sun, but for lack of water ...

a healthy well watered plant deflects disease ... there are many snake oil salesmen who will gladly sell you chemicals to put on an under watered plant ... a healthy plant can take care of itself ...

ken

water - and these are prone to early leaf drop at times. I think it's water and regardless if I or Ken are 100% right, you should keep them more wet.

Dax

The browning does not really match up, but have you looked for spider-mites??? Take a white piece of paper, hold it under a branch and slap the branch several times. You hopefully will have several types of insects, but VERY small ones moving slowly (rule of thumb...good bugs move quickly:-) ) could indicate spider mites. If you smear them on the paper, they will often leave a redish color.
Not many diseases on this plant that I am aware of, just mites and nutritional problems.

Mites leave stippling marks (little pin-sized yellow dots).

Dax

True, but I have seen a mild bronzing/browning when population is low, but under high heat conditions (and that could have been coincidence).
So is the brown "dead tissue" or could it be heat stress??????