Seed-starting mix contains zero soil—it is a sterile blend of fine peat, vermiculite, and perlite designed to be pathogen-free and ultra-light so fragile seedling roots encounter zero resistance.
Indoor Seed Starting Under Lights: The Complete Step-by-Step Guide
Avoid leggy seedlings with our temperature, moisture, lighting distance, and bottom-watering germination protocol.
Johny Alex•Founder & Head Grower
Field-tested vegetable growing specialist
Choosing Seed Starting Mix vs. Potting Soil
The single most common indoor seed starting error is placing lamps too high. High grow lights cause seedlings to stretch and become spindly (leggy). Keep LED or T5 tubes 2 to 3 inches above seedling tops.
The 2-Inch Light Distance Rule
Damping off is a soil-borne fungus that causes seedling stems to wither and collapse at the soil line. Water trays from below and run a gentle oscillating fan on low to strengthen seedling stems.
Bottom Watering and Air Circulation to Stop Damping Off
Consistent execution and monitoring are the keys to a thriving crop. Ensure your soil stays evenly moist, inspect leaf undersides weekly for early pests, and harvest at morning peak crispness.
Frequently Asked Questions
When should I start indoor seeds before spring?
Most crops (tomatoes, peppers, eggplants) should be started 6 to 8 weeks before your historical average last spring frost date.
Johny Alex
8+ Years in Small-Space & Raised Bed Food GrowingFounder & Head Gardener
I believe anyone with a square foot of sunlight can grow real, delicious food. Over 8 years ago, I started with two cracked terracotta pots on a drafty balcony and killed my first batch of tomatoes. Today, I grow over 40 varieties of heirloom vegetables, greens, and root crops using simple, organic methods that respect the soil and your time.
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