Why Start Seeds Indoors?
Starting seeds indoors extends your growing season by 6-8 weeks and gives you access to hundreds of varieties you will never find at the garden center. It is also dramatically cheaper — a single packet of seeds costs less than one nursery transplant.
What You Need
- Containers: Cell trays, peat pots, or recycled yogurt cups with drainage holes
- Seed-starting mix: Light, sterile, and low in nutrients — never use garden soil
- Light: A sunny south-facing window or a simple shop light with cool-white bulbs
- Heat mat (optional): Speeds germination for heat-lovers like peppers and eggplant
- Labels: You will forget what you planted — trust us
When to Start
Count backward from your last frost date. Tomatoes need 6-8 weeks indoors, peppers 8-10 weeks, brassicas 4-6 weeks. Check your local extension service for exact dates or use the Seedtojar sowing calendar.
Sowing Step by Step
Fill containers with moistened seed-starting mix. Press lightly to eliminate air pockets. Place seeds at the depth indicated on the packet — a general rule is twice the seed diameter. Cover with a thin layer of mix, mist gently, and cover with a clear lid or plastic wrap to maintain humidity.
Light and Temperature
Most vegetable seeds germinate best at 65-75 F (18-24 C). Once sprouts appear, remove the cover and provide 12-16 hours of light daily. Keep lights 2-4 inches above seedlings and raise them as plants grow. Insufficient light leads to leggy, weak stems.
Transplanting Outdoors
Harden off seedlings by gradually exposing them to outdoor conditions over 7-10 days before transplanting. Start with a few hours in shade, then increase duration and sun exposure. After your last frost date, transplant on a cloudy day or in the evening to reduce shock.
Track every variety, sowing date, and outcome in Seedtojar so you know exactly what works in your garden year after year.