These are classed as a hardy bonsai (I assume that's how you're growing it!) and can be left outside. However if we have a severe winter again it would be best to move it to a sheltered spot to stop the roots from freezing completely.

Thanks for your reply,
Derek Carey

I hope you dont mind another question . I am a bit confused about watering my trident maple ,With the amount of rain we get it is wet all the time .Is this right or should i keep it sheltered from the rain,
Again many thanks,
Derek Carey.

As long as the excess water can drain freely and the container is not left standing in water, it should be fine. One of the problems with bonsai is getting enough water for them as the containers are shallow. Yours sounds fine.