Growing Guide: Seed Starting Indoors
- Fill the planting tray or pots with seedling mix to within ¼” from the top. Press lightly down to make the soil firm (but don’t pack).
- Lightly moisten the mix thoroughly with fresh water before you begin seeding (if you’re using peat pots pre-soak them now)
- Place your seeds on the soil surface and lightly press down to get good contact with the moist soil.
- Lightly cover the top of the seed with soil and moisten the top, being careful not to wash your seeds
away. - Cover the container with clear plastic wrap or a plastic lid and place it in a warm, brightly lit spot. Great if you have a heat mat.
- Keep the containers evenly moist but be careful not to overwater.
- Once the seed has broken the soil surface, remove the plastic cover.
- Thin any seedling to prevent crowding and disease issues.
- Once the first set of leaves emerges, water weekly with half strength liquid fertilizer.
- Two weeks before planting outdoors, begin to “harden off” the seedlings by moving them outdoors for several hours a day, gradually increasing the length of time and exposure to sun over the two weeks.
- When ready to transplant outdoors, choose a cloudy day if possible, to minimize stress. Thoroughly water the area first, then dig a hole twice as wide as the root ball, cover the top of the root ball with about ¼” of soil and water thoroughly.
Tricks of Trade
- Even though you may think your window is bright, most seedlings need more light than we naturally get in the winter in the Pacific Northwest. Fluorescent grow lights are a great way to get supplemental light for seedlings. Use a small circulating fan to get good air flow around your seedlings and help prevent disease.
- Covering the top of the soil with a 50/50 mix of sphagnum moss and chicken grit will help prevent damping off by keeping the base of the plant dry. Sphagnum moss also has some natural fungicidal properties.
- Use a mist bottle to keep the soil surface moist without overwatering.
Troubleshooting
Seedlings Sprout, But Are Thin & Leggy
The problem: Insufficient light. Supplement natural daylight with fluorescent bulbs.
Seedlings Sprout, But Fall Over & Die
The problem: a fungal disease called damping off that attacks the stem at the base of the plant. Prevention is the best cure – use sterile seeding media, thin seedlings to prevent overcrowding, avoid extreme temperature changes, and don’t overwater.
Seedlings Don’t Sprout
The problem: the seed wasn’t fresh. Check the package for recommended freshness times. The problem: Insufficient light or heat. Many seeds need light to germinate – check the location of the plants and supplement with fluorescent lights or move to a brighter spot. Check that the soil isn’t too cold – 65° to 70° F is optimum.
Yellow Leaves
The problem: nutritional deficiency. Seeds only contain enough stored nutrients to get them through the sprouting process. Once the first set of leaves emerge, fertilize with an all-purpose water-soluble feed.