Hello there, can someone please help me I think my bonsai is dying as leaves haven’t grown for months or when they do it’s one or two which just fall off. It’s not drinking water and there is a white powdery mould on trunk. Any advice or help will be greatly appreciated. Many thanks. Jamie  I think my bonsai is dying as leaves haven’t grown for months and there is a white powdery mould on trmy bonsai is dying as leaves haven’t grown for months and there is a white powdery mould on trunk, please help

The key to find out what is wrong lays in information about what species it is and what care and conditions you give it. So please share some more information.

I think it’s a Chinese elm but not entirely sure. I keep it on the window seal in the kitchen and water once roughly every 2 weeks

No surprise it is almost dead then watering is crucial to a plants' survival. Without it it will suffer and eventually die. You have it inside and are almost certainly not watering enough and it is on its' last legs.

So what should I do then, I’ve watered it loads and it doesn’t seem to be drinking anymore water. What’s all the white stuff around the trunk. If you had this bonsai in your hands what would you do right now?

The white stuff is probably calcium build up. You probably water just enough to keep the soil wet. Then the water dries up leaving hard water chemicals behind. 

Pour water over it until water pours out of the drainage holes. Take the tree outside and let wind and rain do their thing. It looks like a green bud trying to pop up so maybe fresh air and sunlight will give it what it needs. 

If you live in the nortern hemisphere this is a very bad situation.

If you keep it indoors in livingroom conditions it will die in winter.

If you put it outdoors now, late authum, it is not ready for winter and will die.

I would put it in a heated overwintering room at 5c and full sun. That is where there are biggest chanse of survival, Not everyone has that option.

Thank you for your messages, I took a risk and put the bonsai outside in the front of my house during the day and through the night, and so far it has been fine, even some small growth of the little green buds that was trying to break through. Fingers crossed it continues