Tomatoes are a popular crop for greenhouse gardening, and with good reason. Growing tomatoes in a greenhouse allows for year-round production and protection from pests and harsh weather conditions. Here are some tips on how to seed and care for tomatoes in a greenhouse:

1. Choose the right time: Tomatoes should be seeded indoors in late winter to early spring, about 6-8 weeks before the last expected frost date. This will give the seedlings time to grow and develop before being transplanted into the greenhouse.
2. Soil preparation: Choose a well-draining soil mix that is rich in organic matter. Fill small containers or seed trays with the soil mix, and sow the seeds about ¼ inch deep.
3. Temperature: Tomato seeds need warmth to germinate. Keep the soil temperature between 70-80°F (21-27°C), using a heating pad or a warm location in the house.
4. Watering: Keep the soil evenly moist, but not waterlogged. Water the seedlings from the bottom to prevent damping off disease.
5. Light: Tomatoes need plenty of light to grow strong and healthy. Place the seedlings in a sunny location or use grow lights to provide 12-14 hours of light per day.
6. Transplanting: Once the seedlings have grown to about 6-8 inches tall and have developed their first true leaves, they are ready to be transplanted into the greenhouse. Dig a hole in the soil and plant the seedling up to its first set of leaves.
7. Fertilization: Tomatoes require regular fertilization throughout the growing season. Use a balanced fertilizer with a higher phosphorus content to promote fruit development.
8. Watering: Keep the soil evenly moist, but not waterlogged. Use a drip irrigation system or hand watering to avoid wetting the leaves.
9. Pest Control: Monitor the greenhouse for pests such as aphids and whiteflies. Use natural or chemical control methods to prevent infestations.
10. Pruning: Prune the tomato plants regularly to promote air circulation and prevent disease. Remove any suckers that develop between the main stem and the branches.

In conclusion, growing tomatoes in a greenhouse requires careful soil preparation, temperature and light control, regular fertilization and watering, pest control, and pruning. By following these tips, you can successfully grow delicious, juicy tomatoes year-round in your greenhouse.