I have a small sequoia tree which I got from the San Francisco airport as a seedling. I planted it in January 2012 and it has been growing (slowly) and seemed healthy - it is about a foot tall and is planted in normal soil. I notice recently that the needles are browning starting from the base all the way up until about an inch from the top.
Any idea why this would be happening or what I can do to fix this (assuming it needs to be fixed)?