Hmm, let's see. To grow a bigger Christmas cactus, you'll need to make sure it gets plenty of light, but not too much direct sunlight. You should also make sure it's getting enough water, but not too much. Be sure to fertilize it regularly and keep the soil moist but not soggy. It's also important to prune it regularly to encourage new growth. If you follow these steps, your Christmas cactus should thrive and grow to its full potential. Good luck!