Cilantro (also called coriander) is the fastest herb you can grow from seed — ready to harvest in just 3-4 weeks. But there's one thing every beginner gets wrong: cilantro bolts (flowers and sets seed) almost instantly in heat. Master the timing and succession planting, and you'll have fresh cilantro all season.
Cilantro Quick Facts
| Factor | Details |
|---|---|
| Difficulty | Very Easy |
| Days to harvest | 20–30 days (leaves), 45–60 (full plant) |
| Sunlight | 6+ hours (tolerates partial shade) |
| Soil pH | 6.0–7.0 |
| Spacing | 15–20 cm (6–8 in) apart |
| Ideal temperature | 10–21°C (50–70°F) |
| When to plant | Spring and autumn (avoid hot summers) |
Why Cilantro Bolts (and How to Stop It)
Cilantro bolts when temperatures consistently exceed 25°C (77°F). Once it flowers, the leaves become bitter and thin. The solution:
- Spring planting: Start as soon as soil can be worked (late winter/early spring)
- Succession planting: Sow seeds every 2 weeks for continuous harvest
- Summer break: Stop planting in June–August; resume in August for autumn crop
- Autumn planting: Plant 8–10 weeks before first frost for extended harvest
- Afternoon shade: In hot climates, afternoon shade extends harvest window by 2–3 weeks
Cilantro Varieties
- Slow-bolt types (Santo, Slo-Bolt): Better heat tolerance; still bolt eventually but slower
- Standard types (Cilantro, Calypso): Fastest growing but bolt quickest in heat
- Coriander seed types (full plant): Grown for seeds (spice) rather than leaves; larger plants
For maximum leaf harvest, stick with standard or slow-bolt types and use succession planting.
How to Plant Cilantro: Step by Step
From Seed (Direct Sowing)
- Prepare: Loosen soil, rake smooth, mix in compost (not heavy nitrogen).
- Sow: Sprinkle seeds directly, cover lightly with soil (seeds need light to germinate).
- Space: Thin seedlings to 15–20 cm apart when 5 cm tall.
- Water: Keep soil consistently moist (not waterlogged) until established.
- Timeline: Germination 7–10 days; first tiny leaves appear in 2 weeks.
Succession Planting (Secret to Year-Round Supply)
Every 2 weeks (spring–autumn), sow a new patch:
- Week 1: Plant patch A
- Week 3: Harvest from patch A, plant patch B
- Week 5: Harvest from patch B, plant patch C
- Result: Fresh cilantro every 2 weeks without gaps
Cilantro Care
- Watering: Regular, even moisture; cilantro dislikes drought but also hates waterlogging
- Feeding: Light nitrogen feed (half-strength) at week 2; skip heavy fertilizing (promotes bolting)
- Thinning: Don't skip this — crowded plants bolt faster and produce thin leaves
- Mulch: Helps keep soil cool and retain moisture (especially in spring/autumn)
Indoor Cilantro Growing
Cilantro grows well indoors under LED grow lights (12–14 hours/day):
- Use potting mix in a 5-gallon (20 L) container or divided seed trays
- Sow seeds directly; thin to 10–15 cm spacing
- Water when top inch is dry
- Harvest leaves from outside inward once 10 cm tall
- Indoor crop avoids heat-bolting entirely — harvest for months
When to Harvest Cilantro
Leaf Harvest (Best Flavor)
- Start when plant is 10–15 cm tall (about 3 weeks)
- Pinch or cut outer leaves first; inner leaves keep growing
- Harvest in the morning after dew dries (best flavor, longer shelf life)
- Stop harvesting once flower buds appear (energy goes to seeds, leaves turn bitter)
Coriander Seed Harvest (Bonus!)
- Let some plants flower and set seed pods
- When seed pods turn brown and dry, cut stems and hang to dry
- Seeds naturally fall into a container; store in cool, dry place
- Use seeds in curries, pickling, and baking
Health Benefits of Cilantro
Cilantro is rich in vitamin K (essential for bone health and blood clotting), vitamin A, and antioxidants. The essential oils have antimicrobial properties. Fresh cilantro aids digestion and pairs perfectly with lime, garlic, and chili — key to Mexican, Indian, and Southeast Asian cuisines.
Note: About 14% of people have a genetic variation that makes cilantro taste soapy. It's not a defect — just different taste perception!
Common Cilantro Problems
| Problem | Cause | Fix |
|---|---|---|
| Bolting at 3 weeks | Heat, crowding, or stress | Use slow-bolt varieties; succession plant; partial shade in summer |
| Weak, thin leaves | Too much nitrogen or overcrowding | Thin seedlings; avoid high-N fertilizers |
| Leaves taste bitter | Plant is flowering or stressed | Harvest younger plants before bolting; keep consistently watered |
| Seeds won't germinate | Old seeds or planted too deep | Use fresh seed; sow shallowly (light is needed) |
| Damping off (seedlings collapse) | Fungal disease from wet soil | Improve drainage; don't overwater; ensure good air circulation |
| Aphids | Warm weather pest | Spray with water; use neem oil if heavy infestation |
FAQ
Can I regrow cilantro from grocery store bunches? No — grocery cilantro has no roots. You need to grow from seed.
How many plants do I need for regular cooking? For weekly salsa/curry: 3–4 patches of 8–10 plants each (via succession planting). For occasional use: one patch of 6 plants.
Can I save cilantro seeds for next year? Yes! Let 2–3 plants flower, dry completely, and collect seeds. They store for 3–4 years in cool, dry conditions.
Why is my cilantro tall and spindly? Not enough light (even indoors). Move plants closer to window or grow lights (within 15 cm).
Can I grow cilantro in winter indoors? Yes! Indoor is actually ideal for winter growing (no bolting from heat). Use LED grow lights 12–14 hours daily.
Cilantro + Companion Plants
- Nearby: Tomatoes, beans, onions, lettuce (cilantro's low shade helps lettuce in summer)
- Avoid: Fennel (they inhibit each other)
Related Growing Guides
Check exact cilantro planting dates and seasons for your country on our crop calendar.
Frequently Asked Questions
Can I regrow cilantro from grocery store bunches? +
No — grocery cilantro has no roots. You need to grow from seed.
How many plants do I need for regular cooking? +
For weekly salsa/curry: 3–4 patches of 8–10 plants each (via succession planting). For occasional use: one patch of 6 plants.
Can I save cilantro seeds for next year? +
Yes! Let 2–3 plants flower, dry completely, and collect seeds. They store for 3–4 years in cool, dry conditions.
Why is my cilantro tall and spindly? +
Not enough light (even indoors). Move plants closer to window or grow lights (within 15 cm).
Can I grow cilantro in winter indoors? +
Yes! Indoor is actually ideal for winter growing (no bolting from heat). Use LED grow lights 12–14 hours daily.