The variety of umbrella pine that you have is a slow growing, more narrow form, and it should do well in a container. In my garden, our umbrella pine grew slowly in a pot but then zoomed into a six foot tree as soon as we planted it into the ground. For this reason I suggest if you want to keep your umbrella pine on the small side, don't give those roots much room. Keep it in the 2-gallon pot for several years and then move it up to the next size pot once you see roots trying to escape from the drainage holes or when the pot is full of roots. Do the transplanting on a cloudy day in early spring and make sure the new pot has good drainage. You will need to fertilize this tree every spring if it lives in a container, but use a slow release plant food like Osmocote at half the recommended rate. Your goal should be to keep the Joe Kosey tree happy but not growing too fast. In winter move the pot close to the house to keep the soil from freezing and in summer keep it out of the hot afternoon sun to keep the needles from burning or turning yellow. You should not need to water in winter or spring and in summer don't let the soil dry out but make sure it is dry to the touch before you water. Restricting the water is another way of keeping this tree small and happy in a container. Don't worry too much—this is one tough but beautiful tree. Keep growing, Marianne Binetti