Growing peppers from seed in a greenhouse involves creating a warm, controlled environment to encourage germination and early growth. Here's a step-by-step guide:
1. Timing is Key:
- Start 6-8 weeks before the last expected frost. This allows seedlings ample time to develop before transplanting outdoors (if desired) or moving to larger containers within the greenhouse.
2. Seed Starting Supplies:
- Pepper Seeds: Choose varieties suited to your growing conditions and preferences.
- Seed Starting Mix: Use a sterile, well-draining mix specifically formulated for seed starting. Avoid garden soil, as it can harbor diseases and doesn't drain well.
- Seed Trays or Pots: Use seed trays with individual cells or small pots to start the seeds.
- Humidity Dome (Optional): Helps maintain consistent moisture levels during germination.
- Heat Mat (Recommended): Provides consistent bottom heat, crucial for pepper seed germination.
- Grow Lights (Recommended): Supplement natural light, especially during early growth stages.
- Spray Bottle: For gentle watering.
3. Sowing the Seeds:
- Moisten the Seed Starting Mix: Thoroughly moisten the mix before filling the seed trays or pots. It should be damp, not soggy.
- Sow Seeds: Sow 2-3 seeds per cell or pot, about ¼ inch deep.
- Cover Seeds: Lightly cover the seeds with the seed starting mix.
- Water Gently: Use a spray bottle to gently water the surface. Avoid overwatering.
4. Germination:
- Maintain Warmth: Pepper seeds need warmth to germinate. A soil temperature of 80-90°F (27-32°C) is ideal. Use a heat mat to achieve this.
- Provide Humidity: Cover the seed trays with a humidity dome or plastic wrap to maintain moisture.
- Monitor Moisture: Check the moisture level daily and mist with water as needed to keep the mix consistently damp.
- Ventilate: Once seeds start to germinate, gradually reduce humidity by removing the dome or plastic wrap for increasing periods each day. This helps prevent fungal diseases.
5. Seedling Care:
- Light: Once seedlings emerge, provide adequate light. If using grow lights, position them a few inches above the seedlings. Adjust as the plants grow. Aim for 14-16 hours of light per day.
- Watering: Water when the top inch of soil feels dry. Water thoroughly, but avoid overwatering.
- Air Circulation: Ensure good air circulation to prevent fungal diseases. A small fan can help.
- Thinning: Once seedlings have their first true leaves (the second set of leaves that appear after the initial seed leaves), thin to one seedling per cell or pot by snipping off the weaker seedlings at the soil line.
- Fertilizing: Begin feeding seedlings with a diluted liquid fertilizer (half strength) once they have their second set of true leaves. Repeat every 1-2 weeks.
6. Transplanting:
- Transplant to larger containers when the seedlings have developed a strong root system and are several inches tall. Use a good quality potting mix.
- Harden Off (if transplanting outdoors): Gradually acclimate seedlings to outdoor conditions by exposing them to increasing amounts of sunlight and wind over a period of 7-10 days before transplanting into the garden.
- Greenhouse Growing: If remaining in the greenhouse, transplant into larger pots or raised beds within the greenhouse.
7. Ongoing Greenhouse Care:
- Maintain Optimal Temperature: Peppers thrive in warm temperatures, ideally between 70-85°F (21-29°C) during the day and 60-70°F (16-21°C) at night.
- Watering: Water regularly, allowing the soil to dry slightly between waterings. Avoid overhead watering, which can encourage fungal diseases.
- Fertilizing: Continue fertilizing regularly with a fertilizer formulated for peppers.
- Pollination: Peppers are self-pollinating, but gently shaking the plants or using a small fan can help with pollination in a greenhouse setting.
- Pest and Disease Control: Monitor plants regularly for pests and diseases and take appropriate action as needed. Good air circulation and preventative measures are key.
