每日吃瓜

Live in a 5a zone, I've had this Juniper 每日吃瓜 for 5 months and just started the colder winter season. Noticed the weird bark colour and texture shown in the first two images late fall.

Is this normal for Junipers? Did I over water it at some point? And it this still a healthy bonsai?

As young branches age, they turn from green to light broun to the normal dark brouwn bark, if that is what you mean. The needles at this time first turn yellow, then light brown to eventually over years fall off. (In bonsai normally people remove the needles when they turn brown by hand)