centaura

Last spring I planted a small lace-bark pine in the front yard, and this spring the last 1/4" of every needle has turned tan. The rest of the needle looks fine, but the ends are a light tan. This will only ever be a landscape tree - though there is a small branch that I might trim off to root and try for a bonsai. It grew fine last year and seemed to take the winter okay.

Anyone know what might be causing my little pine its distress?

-Centaura