Starting seeds indoors is a rewarding way to get a jump start on the gardening season, giving you access to a wider variety of plants than you can find at a local nursery. With the right setup, you can produce strong, healthy seedlings ready for the garden.
1. Timing is Everything
The most critical step is timing. You need to count backwards from your area's average last frost date. Seed packets will tell you the ideal time to start, typically "6-8 weeks before last frost." Starting too early will result in leggy, overgrown seedlings that are difficult to transplant.
2. Gather Your Supplies
- Containers: You can use plastic cell packs, peat pots, or even recycled yogurt cups (be sure to poke drainage holes).
- Seed-Starting Mix: Use a sterile, soilless mix designed for starting seeds. Garden soil is too heavy and may contain disease pathogens.
- Light Source: A sunny windowsill is often not enough. A simple fluorescent shop light or LED grow light kept 2-3 inches above the seedlings is essential for strong, stocky growth.
- Heat Mat (Optional): Many seeds, like tomatoes and peppers, germinate faster with bottom heat.
3. Sowing the Seeds
Moisten your seed-starting mix before filling your containers. Plant seeds to the depth recommended on the seed packet—a general rule is twice as deep as the seed is wide. Plant 2-3 seeds per cell or pot. Once they sprout, you will thin them to the single strongest seedling.
4. Light, Water, and Airflow
As soon as your seeds sprout, place them under your light source for 14-16 hours a day. Keep the soil consistently moist but not waterlogged; watering from the bottom is a great way to prevent damping-off disease. A small fan set on low can provide gentle air circulation, which helps prevent disease and strengthens stems.
5. Hardening Off
This is a crucial, can't-skip step. About 7-10 days before you plan to plant in the garden, you need to acclimate your seedlings to outdoor conditions. Start by placing them in a shady, protected spot for a few hours. Each day, gradually increase the amount of time and sunlight they receive. This process toughens them up for a successful transition into the garden.