The first green shoots mark the transition from seed to plant. A seedling is a young plant that has recently germinated and is still relying partly on the food reserves in the seed. Cotyledons, the seed leaves, appear first; true leaves follow as the plant begins photosynthesis in earnest.

Seedlings are vulnerable. They need consistent moisture, adequate light, and protection from damping-off fungi and pests. Overcrowding leads to weak, leggy growth. Thinning or transplanting into individual pots gives each plant room to develop a sturdy stem and root system.

Hardening off prepares seedlings for outdoor conditions. Gradual exposure to cooler temperatures, wind, and direct sun toughens the tissues. Once they have several sets of true leaves and the weather is suitable, they are ready for the open garden or larger containers.

• Young plant recently grown from seed
• Begins with seed leaves then true leaves
• Requires careful moisture and light
• Needs hardening before outdoor planting