How to start seeds indoors for beginners?
Written by
Olivia Mitchell
Reviewed by
Prof. Charles Hartman, Ph.D.Starting seeds indoors allows novice gardeners to take control of the early growth of plants; the grower can offer prime conditions for germination, and protecting the germinating seedlings from uncertain weather is beneficial. Follow the basic steps to prepare healthy plants for transplanting.
Container Preparation
- Sterile mix: Use disease-free seed-starting medium
- Drainage: Ensure containers have holes
- Depth: Fill within 1/2 inch (1.3 cm) of rim
- Pre-moisten: Dampen soil before planting
Optimal Environment
- Warm crops: Maintain 70-85°F (21-29°C)
- Cool crops: Keep 60-70°F (15-21°C)
- Light position: 2-4 inches (5-10 cm) above plants
- Duration: 14-16 hours daily
Moisture Management
- Gentle watering: Use spray bottles
- Consistency: Keep soil damp like wrung sponge
- Airflow: Run fan 2 hours daily
- Humidity domes: Remove after germination
Once germination occurs, position grow lights correctly. Then, adjust the height as the seedlings grow. A distance of 2-4 inches (5-10 cm) is ideal, as lights located too far away will cause leggy growth, and those located too close will heat up and risk damaging the seedlings. Always use timers for consistent daily light cycles.
Gently hydrate the plants at first with a spray bottle. Then switch to bottom-watering once the true leaves have emerged. Place the seedlings in shallow trays and add water to the trays. The soil will pull moisture up from the bottom, avoiding disturbance or displacement of the soil and preventing any fungal issues.
Hardening off should begin 7 to 10 days before planting outdoors. Start with one hour of shade per day, then progressively increase exposure. In the beginning stages, protect from the wind. Each day, increase the amount of time outside as well. This process helps toughen the cell structure, enabling better survival in various environmental conditions.
Monitor for damping-off disease. White fungal growth at the soil level signals trouble. Improve airflow immediately. Reduce watering frequency. Space seedlings further apart. Prevention beats treatment for healthy starts.
Read the full article: When to Start Seeds Indoors: Ultimate Guide
