Bonsais do the best in outdoor conditions. They are considered temperate-climate plants, and they must go through a cold dormancy period in order to grow appropriately. However, it's possible to grow bonsai indoors as long as they have received their period of dormancy.
Purchase bonsai seed at a garden store or online. Find an area in your yard that has plenty of sunlight and limited shade. Start your planting in spring If you can. Dig a half-inch hole in the soil, and place the seed into the hole. You will need to grow your bonsai outside until after winter.
Cover the seed, and then sprinkle a half cup of water over it. Continue watering throughout the summer, two to three times a day. You should see the bonsai come up in spring.
Transfer the growing plant to a medium-size pot. Dig an inch-deep hole in the potting soil and place the plant firmly inside. Pack the pot soil firmly around the roots.
Put your bonsai tree in an indoor area with good sunlight, such as a window sill. Make sure you can open the window to allow fresh air onto the plant. Water your plant two or three times a day, and make sure that the water properly drains through the bottom of the pot.
Turn your bonsai tree every day to make sure your tree grows straight. Fertilize your tree every six to twelve months, and prune the roots as your tree grows so that you keep your bonsai small.