Tomato plants are the most popular plant for a spring garden, and there is a market for healthy tomato transplants in the spring. To make money selling tomato transplants commercially, a high-quality product is required and must be available at the right time of the year. If the plants are ready for market too early, customers won't buy them because they don't want to give them protection from a late freeze. If the plants are available for market too late, you'll miss the spring gardening rush and the ability to make a tidy profit.
Purchase tomato seed that is the correct variety for your potential customers. An ounce of tomato seeds is about 10,000 seeds. Also, purchase a sterile potting mix that does not contain soil. There are many types available. A potting medium that contains soil and is not sterile can contain fungi that kill seedlings. Purchase planting trays. A 72-count planting tray holds 72 small plants and is an easy and economical way to start the tomato transplants.
Start seeding trays about six weeks before they are to be brought to market. Add potting mix to the 72-count seed trays, and plant seeds one-quarter inch deep. Place in a heated greenhouse with temperatures between 75 and 85 degrees F. After seeds have one set of true leaves, they need to be moved into larger planting containers. Choose the best-looking plants and move to 4-inch pots for growing out. Be sure the pots are located where there is plenty of natural sunlight so the plants don't become leggy. The best plants are stocky 5- to 7-inch plants with a good root system. The best conditions are daytime temperatures of 70-80 degrees F during the day and 60-65 degrees F at night.
Harden off transplants before bringing to market by setting in full sun for a few minutes each day, gradually increasing the amount of time in the sun until they can stay for at least one hour in the sun without wilting. That process takes about seven to 10 days.