As with other trees, cedars shed old foliage in fall. Sometime in September, part of the foliage- usually in the interior of the tree- will turn rusty brown and slowly fall off (figures 7 and 8). If you're not sure whether your tree is shedding or dying, pulling at the brown foliage is a reliable test, because the foliage about to be shed comes off easily, while the foliage about to die requires a lot of force to remove. From my own observation, I believe that this natural shedding can be reduced by timing one of the heavy pruning sessions to occur around the middle of August.

Fertilizing
Cedars like lots of fertilizer, and I feed mine weekly with a full strength 30-10-10 chemical fertilizer beginning about the end of May and ending the middle of August, with another couple of applications in late September and early October. I alternate between different products, including Miracid. Such fertilizing gives the trees dark green foliage and lots of growth, which, of course, is mostly pruned off, but does contribute to the denseness of the foliage pads. I start with the fertilizing regimen in the year following collecting.

Healthy white cedar foliage in early spring
Naturally occurring deadwood
on white cedar
Close view of white cedar deadwood