Cilantro Seedlings

How to grow cilantro seedlings

Direct sow cilantro seeds directly in the garden — do not start indoors and transplant. Cilantro develops a taproot within the first two weeks that breaks during transplanting, stressing the plant and accelerating bolting by 10–14 days compared to undisturbed direct-sown plants.

This single fact — direct sow only — is the most important thing to know about cilantro seedlings. Everything else (timing, spacing, succession planting) becomes much easier once you stop fighting cilantro’s preference for undisturbed germination in its final location.

See how to grow cilantro for the complete growing guide beyond seedling stage. This article focuses on the starting, germinating, and early-stage care window before the plant is established.

Preparing cilantro seeds for better germination

The brown spherical “seeds” you buy are technically fruits — each contains two actual seeds enclosed in a dry husk. Leaving them whole is fine, but cracking the husk improves germination:

Method: Place seeds between two sheets of paper and roll a rolling pin firmly over them once, or rub between your palms. You’re separating the two seeds inside, not crushing the seed itself. The goal is a visible split in the outer husk.

Result: In my trials, crushed seeds germinate 15–20% more reliably than whole seeds in the same soil conditions. The husk contains germination inhibitors that slow the process.

When to sow cilantro seedlings

Cilantro’s germination sweet spot is 55–70°F soil temperature. It germinates poorly above 75°F and fails entirely above 85°F.

The key timing principle: sow as early as your last frost date allows to maximize the cool-weather window before summer heat forces bolting.

Succession sowing schedule

One sowing gives you one harvest window of 4–6 weeks before that planting bolts. Succession sowing — every 2–3 weeks — gives continuous harvest throughout the cool season.

Example Zone 6 succession schedule:

• March 15 (first sow)
• April 1
• April 21
• May 10 (final spring sow; likely bolts by June)
• Resume August 1 for fall succession
• August 21
• September 10

By the time the first sowing bolts, the second is ready to harvest. See cilantro companion plants — bolted cilantro is not a failure, it’s a beneficial insect magnet.

Sowing cilantro seeds

Soil preparation

Cilantro is not demanding, but it performs best in:

• Well-drained soil: Cilantro is prone to damping-off (fungal seedling collapse) in waterlogged conditions
• Moderately fertile: Too much nitrogen produces lush foliage that bolts faster; average garden soil or a mix of topsoil and compost is ideal
• pH 6.2–6.8: Standard vegetable garden range

Do not add heavy fertilizer before sowing cilantro. Excess nitrogen accelerates bolting.

Sowing depth and spacing

• Depth: 1/4 inch deep; barely covered with soil
• Initial spacing: Sow seeds 2 inches apart across the bed
• Final spacing after thinning: 6 inches apart for leaf harvest; 12 inches apart if you plan to let plants bolt and set coriander seed

Press seeds firmly into the soil after planting — good seed-to-soil contact is critical for germination. Water gently to avoid washing seeds out of position.

Container sowing

Cilantro grows well in containers with these minimums:

• Depth: At least 8 inches; 12 inches preferred for taproot development
• Width: A 12-inch wide container holds 4 cilantro plants at final spacing
• Drainage holes: Essential — no drainage causes root rot within days of heavy rain

Containers dry out faster than garden beds. Cilantro seedlings in pots need water every 1–2 days in warm weather versus every 3–5 days in the ground. See herb garden for container herb setup that includes cilantro.

Germination: what to expect

Days 1–7

Nothing visible. Soil should stay consistently moist — not waterlogged, not drying out. If the surface cracks or turns light-colored between waterings, the moisture is insufficient for germination.

Days 7–14

First cotyledons (seed leaves) emerge. They look like small rounded lobes, not the familiar serrated cilantro leaves. At this stage, seedlings are vulnerable to:

• Damping off: Stems collapse at soil level from fungal infection in waterlogged soil. Improve drainage; avoid overhead watering.
• Birds and slugs: Both eat cilantro cotyledons. Cover with row cover if seedlings disappear overnight.
• Drought stress: Surface drying kills seedlings at this stage faster than any pest.

Days 14–21

True leaves appear — the recognizable lobed cilantro leaf shape. The plant is now more resilient. Begin thinning at this stage.

Thinning cilantro seedlings

Thin to 6 inches apart when plants reach 2 inches tall. Do not skip thinning — crowded cilantro seedlings compete for resources, grow taller and spindlier, and bolt faster than properly spaced plants.

Thinning method: Use scissors or pruning snips to cut thinned seedlings at soil level. Do not pull — pulling disturbs the roots of neighboring plants you intend to keep.

The thinned seedlings are fully edible as microgreens. Use them immediately in salads or as a garnish.

Thinning for coriander seed production

If you plan to let cilantro bolt and collect coriander seeds, thin to 12 inches at the outset. More space per plant means larger, more productive plants with more seed heads per plant.

Watering cilantro seedlings

Cilantro has a narrow watering tolerance:

After the first two weeks, water deeply and less frequently — let the top inch of soil dry between waterings. This encourages the taproot to grow downward rather than staying surface-shallow.

Why cilantro bolts — and how to slow it

Bolting is cilantro’s response to heat and day length. It is not a sign of poor growing conditions — it is genetic behavior that cannot be permanently prevented, only delayed.

What triggers bolting:

• Soil temperature above 75°F
• Air temperature consistently above 80°F
• Day length exceeding 14 hours (summer solstice conditions)
• Water stress (drying out accelerates bolting)
• Root disturbance (why transplanting causes early bolting)

Strategies to slow bolting:

1. Partial shade: Plant on the east or north side of taller plants (tomatoes, peppers) to get afternoon shade. Shade delays bolting by 1–2 weeks in my trials.
2. Slow-bolt varieties: Calypso, Leisure, Delfino, and Santo varieties are bred to resist bolting. They add 1–3 extra weeks before flowering.
3. Consistent moisture: Never let the soil dry out completely during warm weather.
4. Thinning: Properly spaced plants bolt later than crowded ones.
5. Succession sowing: The most reliable strategy — always have a younger planting ready as the older one bolts.

See coriander vs cilantro for what to do with the bolted plant — the seeds (coriander) are a distinct spice worth harvesting.

Slow-bolt cilantro varieties for US gardens

For early spring and fall sowings, standard varieties are fine — the cool weather naturally extends the harvest window. Save slow-bolt varieties for late spring and summer succession sowings where every extra day counts.

Harvesting before bolt

Start harvesting cilantro leaves when plants reach 4–6 inches tall. Harvest the outer stems first, cutting 1/3 of the plant per harvest. This allows the plant to continue producing new growth from the center.

Harvest strategies by sowing stage:

• Young plants (2–4 inches): Do not harvest; let the plant establish
• Established plants (4–8 inches): Harvest outer leaves and stems; leave the growing center
• Bolting plants: Harvest aggressively — once the plant commits to bolting, full-scale harvest maximizes what you get before the flavor changes

Flavor changes as cilantro bolts — the leaves take on a more soapy, less bright taste for some palates. Harvest before bolting for the best-tasting leaves.

After the seedlings: what’s next

Once cilantro is established past the seedling stage (3–4 weeks after germination), the main tasks are:

1. Continue succession sowing every 2–3 weeks
2. Manage harvesting to maximize leaf production before bolting
3. Let at least one plant per sowing go to seed for coriander harvest and seed-saving

The companion planting role of bolted cilantro is covered in cilantro companion plants — the umbrella flowers attract hover flies and parasitic wasps that protect nearby vegetables from aphid and caterpillar pressure. Letting cilantro bolt intentionally in one section of the garden is a sound integrated pest management strategy.