Help: Bonsai Tree

[Sylv]

Last April, I got a bonsai tree (Chinese Elm) for my birthday, fully grown and healthy. I've been attentive to it, giving it plenty of sun light and tepid water every day as instructed by many a 'Bonsai tree care' websites, books etc.
However I moved into a new flat last summer and I've come to believe my tree is 'unhappy' or sick. This is my own fault, I didn't water it everyday and I left the tree on my kitchen window ledge, watering it maybe three times a week.
Over the bitter winter that we had (the flat wasn't heated very well) the leaves have slowly started to discolour, about 60% of the leaves are a healthy green, but the remaining 40% are turning yellow with remaining streaks of green where they were healthy previously, others turning brown and dying. White mildew started to grow on the top soil, I guess it had been suffocating the tree, this being due to the heat and poor ventilation when cooking.
I've recently re-potted it, put it in my lounge, in an area that receives plenty of sunlight and watering it regularly again, the leaves still remain as they were. New shoots are growing, but very slowly and I trim those back anyway.
To those who have a bonsai tree and have a good deal of experience with them, is there anything else I can do to make it healthy again?

 

[Sylv]

Tried for the first port of calls of urinating over it, then the second of course, vomit.
And it's an inside tree. I'll check out the link, cheers.

 

[Sylv]

THERE IS NO SUCH THING AS AN INSIDE TREE!

Also they hate draughty conditions, the fact you are constantly letting the temperature near it fluctuate so much (Cold sill at night, presumably warms up during the day/ evening when there is some heating) does not help.

If you must keep it inside, just keep the temperature as steady as you can and in a bright spot. Also use a gravel tray to try and keep the moisture levels around it a bit higher.

How do you water it?

I was under the impression the conditions outside, especially this time of year, top temperatures of about 6 degrees celsius is far too cold for it to survive. In any case I don't have a garden, so it'll have to stay inside. Moving it into the lounge should keep the temperature variations to a minimum. I water it using half a pint of tepid water to keep the soil moist, through a funnel to disperse the water evenly.

 

[Sylv]

Chinese Elms are very hardy and can survive cold temperatures. In China it does get very cold in some parts at certain times of the year! They do need to be hardened before being left out all winter though, and the roots can still freeze, killing the tree. Typically, the kind of cover you might use to cover up hanging baskets in freezing conditions will keep it safe though.

Mine is in my mum's greenhouse at the moment and is doing just fine. (It's over 20 years old now). In fact, leaving them in the cold is good for them, as it allows them to 'hibernate' during the cold weather and prevents them becoming exhausted.

Also you should not be using water straight from the tap. If you can, leave it to stand overnight or for a couple of days. Water it by simulating rain (i.e. a watering can in the bath if you keep it indoors). Under-water rather than over-water, as Bonsai hate being left sat in lots of wet soil for long periods, and get the poor thing a gravel tray and fill it with damp 'gravel!' (you can buy special stuff from garden centres)

Exactly what I wanted to know. Thank you!