How to Grow the Best Greenhouse Tomatoes?

Many people are passionate about growing greenhouse tomatoes. Here are some Tips for Success in growing the Best Greenhouse Tomatoes.

  • Start seed mid to late March on a heat pad
  • Move the plants 6 inches below grow lights after they sprout. Typically, this will be in less than a week.
  • Transplant the plants when they start to get their first true leaves.
  • Start fertilizing as soon as the tomatoes are transplanted.
  • When the greenhouse temperature is fairly consistently above 10 C (50 F) during both day and night, move the plants into the greenhouse. 
    • Helpful Tip: If you have a greenhouse heater, you can use it to move this timeline up a little bit to maintain the temperature yourself rather than relying on Mother Nature.
  • If the plants are leggy, too tall or floppy, remove the bottom leaves and plant them deeper into greenhouse pots or soil beds.
  • Similar to how some people take multivitamins to add to their daily nutrients, Tomatoes like a number of nutrients in their fertilizer. I personally like fertilizer with kelp and micro-nutrients. I mix it at half strength and water it once a week.
  • Ideally, plants will be short and stocky. If they are thin, they are either too hot, too overwater or under-fertilized. They may also need air movement so add a fan if all other ideas are considered and dismissed.
  • Gradually remove leaves below the fruit trusses. By the end of October, the plant should be almost leafless but with trusses of tomatoes at the top of the plant.