Is he dying? Please help!

[bookworm]

Hi,
I bought what I think is a juniper bonsai tree from a craft show a couple months ago and the seller told me to keep it in the pot in the plastic tray and then keep the water filled to the brim of the tray, but to never water the soil directly. I've done that and kept it near a sunny window for the entire time but today I noticed that there is white mold growing all around the soil and there is a white spot (not mold) on one of the branches. I guess I've overwatered it? But I don't know...I'm completely new to bonsai trees (and basically caring for any plants in general) so please, PLEASE help!

[TomM]

Two very basic things are wrong here. The seller is giving bad advice. His (or her) job is to sell.

Number #1 - Juniper
If juniper grows in the ground where you live it is not an indoor plant/tree. I don't care how hot or how cold it gets juniper belongs outdoors.

Number #2 - Watering
Juniper is not a water plant and should never sit in a tray filled to the brim with water. The roots will rot, needles turn brown, plant will die. Yours may already be dead.

BONSAI is all about keeping a tree in a small pot and giving it the proper care and environment so that it will grow and thrive while artistically styling it as it develops over time. But first and foremost - they are not simply 'houseplants'. We need to know what they are and what they need in order to do well in a container.

[froggy]

Yeah, either it was sitting in water, or trying to survive on air humidity alone. Is the soil bone dry? Then give it a good soaking. If it's wet, get it out of that tray and let it dry a bit. It may already be too late either way...
Images would help.