This is a two part question, from someone who has wanted to get into bonsai since childhood and is finally being proactive. One question regarding the state of the tree I just bought, and another regarding the viability of my indoor grow setup.

I purchased a Chinese Elm from a popular website and received it today. It has white residue on many of the leaves, which looks like it could be mildew based on what I've read. It also has some webs on it, which could be spider mites, although I haven't found any mites after testing all of the branches by shaking them while holding a piece of paper under. Can someone with more experience confirm my hunches before I take action?

I live in a major city in the northeast US and have a backyard that only gets about 2-3 hours of sunlight a day. I built this cabinet hoping to be able to grow, shape, and care for bonsai indoors. It has glass doors, two fans (one inflow and one outflow), and four full spectrum strip grow lights at the top. Is this viable to care for bonsai for someone in my situation? Is there a way I can improve it?

I understand this is a common beginner post but I haven't been able to find information completely specific to my situation. I am hoping to learn and start this journey killing as few trees as possible

Chinese elm is a temperate decidious tree. It cannot grow indoors without natural seasonal flucturations. 2-3 hours of direct sun outdoors may not be the best conditions, but it is far better than your indoor setup.

Tu put it frankly. Your tree will die in that setup and there is no doubt about it.

Thanks for the reply. Is it safe to put the tree outside at this point in winter? It’s been averaging about 40 degrees Fahrenheit.

Also still concerned about the potential spider mites and mildew.

If it is safe to put it outdoors now depends on if it has experienced a proper authum. If not, it is not ready for frost. In that case it is best to keep it at 5c until spring and then put it outdoors.

Pest this time of the year is no issue If the tree is kept under the right conditions. Come spring you may be supriced to see nothing on it. Pests is very rare on healthy growing trees in the right environment.

you water with tap water because I noticed traces of limestone on the leaves !!! rain water would be better

Thanks for the reply

I just got the tree and haven’t watered it yet.

If I don’t have access to rain water, what would you suggest? Filtered? Bottled?

Just use the tap water there is nothing wrong with it

Tap water is not at all uniform. It depends largelly where you are and what quality your water are if it is good for your tree or not. Where I am tap water is good for the trees, but may not be where you are.

Just ask your water plant about tap water quality. If you have hard water in your tap, rain water maybe better.

Anyhow.....environment is always number one thing to focus on. Water quality is second, third or even maybe forth thing to focus on.