Overview
- Common Name: Zinnia
- Scientific Name: Zinnia elegans
- Plant Type: Annual flowering ornamental
- Uses: Garden borders, flower beds, pollinator attraction, cut flowers
- Special Note: Easy to grow, drought-tolerant once established, excellent for hot lowland climates
Best Varieties for the Philippines
| Variety | Features | Disadvantages | Typical Height |
|---|
| Zinnia ‘Profusion Series’ | Compact, heat- and rain-tolerant, continuous bloomer. | Smaller flower size (than some large-flower types) | ~12-18 inches (30-45 cm) tall. |
| Zinnia ‘Dreamland Series’ | Large, dahlia-like blooms, various colours, compact habit. | Slightly less tolerant to prolonged rain (by implication of needing good growing conditions) | ~10-12 inches (25-30 cm) tall. |
| Zinnia ‘Lilliput Mix’ | Miniature blooms, ideal for borders and pots, early flowering. | Needs frequent dead-heading (to prolong bloom) | ~15-24 inches (38-60 cm) tall. |
| Zinnia ‘State Fair Mix’ | Tall (up to ~90 cm / ~3 ft), large flowers, strong visual impact. | Needs staking; prone to mildew in humid weather | ~24-46 inches (60-115 cm) tall. |
🟢 Best Choice for Philippine gardeners:
Profusion or Dreamland Series — both withstand tropical heat and short rainfall periods.
Germination from Seeds
- Propagation: From seeds
- Seed Treatment: No soaking or refrigeration needed
- How to Germinate:
- Sow seeds directly into garden soil or seed tray.
- Lightly cover with 0.5–1 cm of soil.
- Mist gently; keep soil moist until germination.
- Germination Time: 5–7 days
- Ideal Soil pH: 6.0–7.5
- Soil Type:Well-draining loam or sandy loam mixed with compost
- Why: Prevents root rot and allows healthy root expansion.
- Sunlight Exposure (during germination): Bright, indirect light or early morning sun.
Transplanting
- When to Transplant: After 2–3 true leaves appear (10–15 days old)
- Spacing:
- Dwarf: 15–20 cm apart
- Medium: 25–30 cm apart
- Tall: 40–45 cm apart
- How Deep: Transplant at same depth as seedling base
- Best Time to Transplant: Early morning or late afternoon on a cloudy day
- Sun Requirement: Full sun (6–8 hours/day) — essential for strong stems and vibrant color
Growth & Soil Conditions
- Sunlight: Full sun; blooms best under high light and heat.
- Watering: Moderate — water only when top 2–3 cm of soil is dry.
- Avoid: Constantly wet soil; roots will rot easily.
- Soil Condition: Loose, well-drained, enriched with compost.
- Mulching: Recommended to reduce weeds and retain moisture during dry season.
- Air Circulation: Maintain spacing to prevent fungal disease in humid months.
Fertilizer Needs
| Growth Stage | Fertilizer Type | Frequency | Purpose |
|---|
| Seedling / Early Growth | Diluted organic compost tea or vermicast extract | Every 2 weeks | Promote leaf and root growth |
| Pre-flowering Stage | Balanced fertilizer (14-14-14 or 10-10-10) | Every 3 weeks | Build stem strength and prepare for blooms |
| Flowering Stage | Phosphorus and potassium-rich (10-20-10 or banana peel tea) | Every 2 weeks | Encourage vibrant, long-lasting flowers |
⚠️ Tip: Avoid excess nitrogen — it promotes leafy growth but reduces flowering.
Pruning & Maintenance
- Pinch back young plants (around 15 cm tall) to encourage bushier growth and more flowers.
- Deadhead regularly (remove spent blooms) to prolong the flowering season.
- Staking: For tall varieties, tie to bamboo sticks to prevent bending.
- Weeding: Keep the area clean to prevent pest nesting.
Common Pests & Diseases
| Problem | Symptoms | Organic Control / Prevention |
|---|
| Aphids / Whiteflies | Sticky residue, distorted leaves | Neem oil or soap spray weekly |
| Powdery mildew | White powdery coating on leaves | Ensure airflow, avoid overhead watering |
| Leaf spot (fungal) | Brown circular spots | Use baking soda spray (1 tsp per liter of water) |
| Spider mites | Fine webbing under leaves | Spray with water or neem oil, maintain humidity |
🟢 Companion Tip: Plant zinnias near tomatoes, peppers, basil, and eggplants to attract pollinators and deter harmful insects.
Flowering & Fruiting
- Days to Flower: 45–60 days from sowing
- Bloom Duration: Continuous flowering for 3–4 months with regular deadheading
- Pollination: Insect-assisted (bees, butterflies)
- Seed Harvest: Wait for flowers to dry completely; seeds are at the base of petals.
Growth Conditions & Lifespan
- Lifespan: Annual (4–6 months)
- Can Regrow From: Seeds only
- Root Condition: Must be well-drained; avoid standing water
- Temperature Range: 22–34°C optimal
- Humidity: Tolerates moderate humidity but avoid overcrowding
- Soil Preference: Lightly sandy or loamy with compost
Best & Worst Planting Months (Philippine Climate)
| Season | Months | Recommendation |
|---|
| Dry Season (Amihan) | November – May | ✅ Best time; intense color, longer blooms, fewer fungal problems |
| Rainy Season (Habagat) | June – October | ⚠️ Not ideal; prone to mildew and stem rot — grow in pots under roof eaves or covered beds |
Additional Tips
- Companion Plants: Marigold, basil, chili, tomato (boosts pollination & repels pests)
- Avoid Planting With: Tall shading plants (they need direct light).
- Seed Saving: Dry flowers on the plant; collect when petals are brown and crisp.
- Container Growing: Works well in pots at least 20–25 cm deep with holes for drainage.
- Pollinator Benefit: Zinnias attract bees and butterflies — ideal for vegetable garden borders.
- Renewal Tip: Re-sow every 3–4 months for continuous color in the garden.