This isn't a topiary question, but a juniper disease question. You need to check with the tree forum. I don't really know what happened but when plant is stressed, it is important not to feed it with any fertilizers.

I did some searches on google (wonderful search tool) and came across this site.

http://hgic.clemson.edu/factsheets/HGIC2056.htm

Is it possible that your plant was wrongly located and now became diseased by some form of fungus?

Ianna

its 11ft tall and 8 yrs old. i have never had a problem with any of my evergreens until now. i feed it with jobes spikes every fall,and the last few weeks it started turning brown from the bottom to the top. the top still has nice green growth,it has not turned brown yet..... if anyone has any ideas please let me know... p.s i have a qt. of Superthrive should i try it??? thanks tom