What is a Seedling?
A seedling is a baby tree—a young plant that has just sprouted from a seed and is in its most vulnerable early growth stage. It's the period from when the seed germinates until the plant is established enough to be considered a young tree.
Seedling Development Stages
Stage 1: Germination
- Seed absorbs water (imbibition)
- Radicle (first root) emerges
- Cotyledons may emerge or stay buried
Stage 2: Cotyledon Stage
- Seed leaves provide initial energy
- First roots establishing
- Most vulnerable period
Stage 3: True Leaf Stage
- First true leaves emerge
- Begin photosynthesis
- Less dependent on seed reserves
- Still considered seedling
Stage 4: Established Seedling
- Multiple true leaves
- Substantial root system
- Independent of seed reserves
- Transition to "sapling" or "juvenile"
Costa Rican Seedling Characteristics
Fast-Growing Species:
- Balsa: Can reach 1m in 3-4 months
- Gallinazo: Rapid early growth
- Large cotyledons
- Quick true leaf production
Slow-Growing Species:
- Almendro: Slow first year
- Many hardwoods: Patient growers
- Longer seedling stage
- Greater seed reserves
Seedling Care
Water: Critical—never let dry out
Light: Match to species tolerance
Protection: From herbivores, weather
Soil: Well-draining, nutrient-rich
Spacing: Prevent competition
Why It Matters
Understanding seedlings helps with:
- Tree propagation and nursery management
- Reforestation success rates
- Species identification
- Conservation efforts
- Understanding forest regeneration