Start Seeds Indoors for a Head Start on Spring Planting

Beat the Frost

Northern gardeners: start frost-tender seeds indoors 4–6 weeks before last frost. Gain a month of blooms/harvest.

Simulate Outdoor Conditions

Basics: soil, water, light. Indoors needs more attention per plant.

Sterile Medium Is Non-Negotiable

Damping-off fungus wipes out seedlings fast. Use commercial sterile mix (peat/vermiculite) or sterilize your own soil in oven. Bag must say “sterilized.”

Containers

Flats, peat pots, Dixie cups, egg cartons—size to plant. Experience guides choice.

Light: Lots of It

• Seedlings need 14+ hrs/day of intense light.
• Even sunny windows often need supplemental grow bulbs (plant-specific).
• Leggy = insufficient light.

Water from Below

• Keep moist, not soggy.
• Bottom-water: pots in tray, pour water in tray.
• Never let pots stand in water.
• Gravel tray in sunny window maintains humidity.

Transition to Outdoors

• Cover with plastic wrap until sprouts emerge—then uncover.
• Don’t start too early; overgrown seedlings need thinning/potting up.
• Harden off: 2+ sets of leaves, 4–6 weeks after sowing.
• Feed weak soluble fertilizer before transplant.

Keep a Journal

Record what works. Experiment yearly. Join online forums for community wisdom.