Start Seeds Indoors for an Early Spring Garden

Why Start Seeds Indoors?

Starting seeds indoors extends your growing season by 6 to 8 weeks. You control temperature, moisture, and light conditions, giving seedlings the best possible start.

When to Start

Count backward from your last expected frost date. Slow-growing crops like onions and peppers need 8 to 10 weeks indoors. Fast growers like squash need only 3 to 4 weeks.

Essential Supplies

You need seed starting mix (not garden soil), seed trays, a humidity dome, grow lights, and labels. A heat mat speeds germination for warm-season crops.

Sowing Seeds

Fill trays with moistened starting mix. Sow seeds at the depth specified on the packet, generally 2 to 3 times the seed diameter. Cover lightly and mist with water.

Providing Light

Place grow lights 2 to 4 inches above seedlings and raise them as plants grow. Provide 14 to 16 hours of light daily. Without adequate light, seedlings become leggy.

Watering and Feeding

Keep soil consistently moist but not waterlogged. Bottom-water by placing trays in a shallow dish of water. Begin fertilizing with half-strength liquid fertilizer once true leaves appear.

Hardening Off

One to two weeks before transplanting outdoors, gradually expose seedlings to outdoor conditions. Start with 1 hour and increase daily over a week.

• Use sterile starting mix to prevent damping-off disease
• Thin seedlings to one per cell to prevent crowding
• Transplant on cloudy days or late afternoon
• Water thoroughly immediately after transplanting