Answer: It is very difficult to grow these trees in containers long term under home conditions. The soil must be kept evenly moist yet not saturated or sopping wet. Small containers dry out very quickly and do not insulate the roots from heat or cold, so it is better to go larger. You would need to use a container proportionate to its top growth when you start, as the roots will be in proportion to that. As it grows, you would need to rootprune and refresh the soil periodically to keep it in scale with the container.
It certainly would not survive outside in the winter. You would need to bring it into a sheltered but cold location in late fall, possibly an unheated garage where it would be cooler than 40 degrees but not freeze. Keep the soil slightly damp -- just not bone dry -- until spring when you would take it back outside again to wake up with the season.
Feed lightly with a slow release fertilizer for acid loving plants in spring. Keep the soil evenly moist during the growing season. Protect it from winds and harsh sun, an eastern exposure with sun all morning seems to work best. Rotate the plant so it does not grow lop sided. Keep an eye out for pests such as mites.
Unfortunately I should tell you that it is unusual for home gardeners to be able to keep these trees in containers for very long. If they do survive the first winter they tend to become stressed and succomb to pest or disease the second summer. I'm sorry I can't be more encouraging.
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