How to Start Tomato Seeds in a Greenhouse
- 1). Choose tomato varieties based on yield, growing requirements, pest-resistance and eating preference. Contact a local agricultural extension office to find tomato varieties suitable for growing in your area.
- 2). Plant seeds twice a year, in spring and fall, for maximum yield. Start spring crops in mid-November for a harvest in late March or early April, and start fall crops in July for harvest in November.
- 3). Start seeds for transplants approximately six weeks before the average frost-free date, to ensure that they are read for outdoor planting at the appropriate time.
- 4). Choose a growing media, such as soil, peat or bark-based growing material, that is well drained and rich in organic material. Allow .5 to 1 cubic foot of media per plant.
- 5). Plant seeds approximately 1/4 inch deep, in moist soil.
- 6). Maintain a greenhouse temperature of 75 to 90 F while seeds germinate. Plants will begin to sprout in three to five days.
- 7). Maintain a greenhouse temperature of 60 to 70 F while plants are developing, to prevent them from getting leggy.
- 8). Apply a small amount of water-soluble fertilizer, rich in potassium, magnesium, calcium and phosphorus and moderate in nitrogen, at each watering.
- 9). Water regularly and do not allow soil to get completely dry. Drip irrigation systems with timers are effective in maintaining plant moisture levels.
- 10
When plants reach 10 inches in height, attach them to a strong stake or a string suspended from the ceiling to support the plants. Attach plants to the support using clips, and re-attach every six to 10 days.
