gregb

While juniper is considered evergreen, the foliage is replaced by the tree occasionally. Your tree may just be sloughing some old needles since we are starting to head into winter. Keep an eye on it, it may be spider mites.

I would be more concerned about the way you are watering the tree. Watering by immersion is an emergency procedure used to revive trees that have been neglected and are dying of lack of water. It can be used occasionally during the hottest part of the growing season when daily watering just isn't quite cutting it. You chould be watering from overhead from a hose with a fine rose attached for a shower effect that pulls air behind it as the water exits the drain holes of the pot. This does not happen when watering by immersion--the water displaces all the air in the pot then only drains incompletely. A "perched layer" of water constantly remains near the drainage layer of your pot setting up an anaerobic environment that fungus and bacteria of the bad variety may thrive. The lack of soil air in that layer can also kill roots.