Tomatoes are aggressive, thriving plants that flourish in gardens around the world. They are equally successful in potted environments, though, and do well on porches and even grown indoors. According to Bonsai Gardener, bonsai growing actually means container, or pot, growing. When grown in pots, tomatoes maintain smaller sizes and less reach than when grown in gardens. To grow tomato plants as bonsai plants, then, grab some seeds, choose your pots and get started.
Start tomato seeds eight to 10 weeks before you plan to put the plants outdoors. Don't put tomato plants outside until after the last frost. Ideal starting time for tomato seeds is March to April.
Fill your small pots or a planting tray with a mixture of half quick-draining potting soil and half compost. Plant tomato seeds two to a pot, 1/8 inch to 1/4 inch deep in the soil. Sprinkle soil over the planted seeds.
Set the planting tray in a sunny window or under fluorescent lights and use a watering can to avoid displacing the seeds when you water. Give the plants 1/2 inch of water every other day to keep the soil consistently moist.
Monitor the tomato seeds and expect sprouting within weeks. When tomato plants are several inches tall, transplant them to individual pots with the same mixture of soil. Place the potted "bonsai" tomatoes on the porch or in window sills and maintain moisture.
Allow tomato plants to grow naturally, or prune them as decorative bonsai plants. Follow traditional bonsai pruning and shaping procedures for decorative plants.