Fertilizer for Beginners: What, When, How
Fertilizer is plant vitamins, not food. Use liquid fertilizer at 1/4 strength for seedlings, full strength for established plants. Every 2 weeks.
Over-fertilizing is the most common beginner mistake. It kills plants.
NPK
| Number | Nutrient | Function |
|---|---|---|
| N | Nitrogen | Leaves |
| P | Phosphorus | Roots, flowers |
| K | Potassium | Overall health |
When to Fertilize
| Stage | Fertilize? |
|---|---|
| Germination | No |
| Seedlings (1-3 weeks) | No |
| Seedlings (3+) | 1/4 strength |
| Vegetative | Every 2 weeks |
| Flowering | Every 1-2 weeks |
| Dormant | No |
Types
| Type | Best For |
|---|---|
| Liquid | Containers, quick fix |
| Granular | Outdoor beds |
| Slow-release | Containers |
| Organic | All |
Over-Fertilizing Signs
- Brown leaf edges
- White crust on soil
- Wilting despite wet soil
Fix: Flush soil with water.
Common Questions
Can I fertilize seedlings? Not until 2-3 sets of true leaves.
Is organic better? Not necessarily.
How often for tomatoes? Every 1-2 weeks.
Should I fertilize in winter? No. Dormant.
Can I over-fertilize? Yes. Most common beginner mistake.
What if I never fertilize? Container plants starve in 4-6 weeks.