The best containers for an indoor lemon tree are those with lots of drainage holes, such as clay pots (preferably glazed ones), ceramic dishes, and concrete bowls. Also, look for containers that are large enough for your plant. Make sure there are at least four inches between the top of the soil and the rim of the container. When growing a citrus tree in a container, you will have to be careful about watering it because too much moisture around its roots may cause root rot - even if your container has drainage holes. You will also want to fertilize your tree more often than outside trees because it isn't able to soak up nutrients as well as a plant that's planted in the ground.