Cilantro microgreens taste like the herb you know, only softer and greener, which makes them a great garnish for tacos, curries, noodle bowls and salsas. They are also one of the slower microgreens, and most failed trays come down to one detail: the seed. If you want to know how to grow cilantro microgreens reliably, start with split seed, give it a long, humid blackout and keep the room on the cool side. This guide gives you exact numbers for a standard 10×20 tray.
Key takeaways
- Use split coriander seed; whole seeds are two seeds inside a hard husk and germinate slowly and unevenly.
- Sow about 25–40 g per 10×20 tray, after an optional 2–8 hour soak.
- Expect a long blackout of about 6–9 days before most seeds are up.
- Cilantro prefers cool conditions: about 60–70°F (16–21°C).
- Harvest around day 15–21, when the narrow seed leaves are open and the first true leaf is appearing.
Split vs. whole coriander seed
Cilantro and coriander are the same plant. What is sold as a coriander “seed” is actually a small round fruit that contains two seeds inside a tough husk. Growers buy split seed for microgreens, where each fruit has been cracked into two halves. Splitting does two things: it lets water reach the seed faster, and it roughly doubles the number of sowing units per gram, so the tray fills more evenly.
Whole seed does work, but germination is slower and patchier. If you only have whole seed, you can crack it gently by rolling it on a cutting board under a flat-bottomed glass, then soak it. Make sure any seed you use is untreated and sold for sprouting or microgreens.
What you need
- 25–40 g of split cilantro seed per 10×20 tray. Use the microgreens seed calculator to scale it for other tray sizes.
- A 10×20 tray with holes, a holeless tray to sit it in, and a cover tray.
- 1.5–2 inches (4–5 cm) of moist soil mix or coco coir. Cilantro grows better in soil than on mats; see the best growing medium for microgreens.
- A light weight of 2–5 lb (1–2 kg), a spray bottle and a grow light on a timer.
How to grow cilantro microgreens step by step
Step 1: Soak (optional, 2–8 hours)
Soak split seed in room-temperature water for 2–8 hours, then drain thoroughly. Soaking softens the husk and can shave a day or two off germination. Do not leave it soaking overnight and forget it; seed that sits in water too long can sour. Our guide to soaking microgreen seeds explains the trade-offs.
Step 2: Sow on firm, moist mix
Level and lightly press pre-moistened mix in the tray. Spread the seed in a single, even layer; the halves should touch but not stack. Mist well. Because cilantro takes so long to come up, many growers add a very thin dusting of fine mix or vermiculite over the seed to keep it from drying out.
Step 3: Long, humid blackout (6–9 days)
Cover with an upside-down tray and a light weight, and keep the tray at about 60–70°F (16–21°C). Check daily and mist whenever the surface looks dry. The first sprouts usually appear around day 4–7, and most of the tray is up by day 6–9. Remove the cover once the majority of seedlings are about 1 inch (2–3 cm) tall. The microgreens blackout period guide shows what that stage looks like.
Step 4: Light for 8–12 days
Move the tray under 12–16 hours of light a day, with LEDs about 6–12 inches (15–30 cm) above the seedlings. The long, narrow seed leaves green up within a day. Cilantro stretches quickly in dim light, so a bright, close light keeps the stems sturdy. Our guide to grow lights for microgreens covers simple setups.
Step 5: Bottom water
Water from below once the tray is uncovered: add 1–2 cups (250–500 ml) to the bottom tray, wait 10–15 minutes, then pour off the rest. Water when the tray feels light. Because cilantro spends close to three weeks in the tray, keeping the leaves dry and the mix moist but not soggy is the best defense against mold. See our microgreens watering guide.
Step 6: Harvest (day 15–21)
The seed leaves of cilantro are long and grass-like and taste milder than the herb. The familiar cilantro flavor gets stronger once the first true leaf (the small lobed leaf) appears, which is why many growers wait until around day 15–21. Stop watering about 12 hours before you cut, then harvest just above the soil with sharp scissors. Store dry greens in a covered, paper-towel-lined container in the fridge. Our harvesting guide has the details.
Cilantro microgreens at a glance
| Stage | Cilantro | Basil (for comparison) | Radish (fast crop) |
|---|---|---|---|
| Seed per 10×20 tray | 25–40 g (split) | 10–20 g | 25–35 g |
| Soak | Optional, 2–8 h | No | No |
| Blackout | 6–9 days | 3–5 days | 2–3 days |
| Harvest | 15–21 days | 14–21 days | 7–10 days |
| Best temperature | 60–70°F (16–21°C) | 70–80°F (21–27°C) | 65–75°F (18–24°C) |
| Difficulty | Medium | Medium | Easy |
These are starting ranges; seed lots and room conditions vary. For a side-by-side view of other crops, see the seed-per-tray chart and how to grow basil microgreens.
Troubleshooting cilantro microgreens
| Problem | Likely cause | Fix |
|---|---|---|
| Very few seeds sprouted | Whole (unsplit) seed, old seed, or surface dried out | Use split seed, keep the surface damp during blackout, test old seed first |
| Germination taking 10+ days | Room too cold, or unsoaked whole seed | Keep the tray near 65°F (18°C) and soak split seed 2–8 h |
| Husks stuck on the leaves | Dry husks lifted by seedlings | Use weight during blackout and mist before brushing them off |
| Thin, floppy stems | Weak light | Lower the light and run it 12–16 hours a day |
| Gray fuzz at the base | Overwatering and still air over a long grow | Water from below only when needed and add a small fan |
For more help, see seed hulls stuck on microgreens, microgreens not germinating and mold vs. root hairs.
Tips for a better cilantro tray
- Start it early. Sow cilantro a week before faster crops if you want everything ready at the same time.
- Keep it cool. A spot that stays in the mid-60s °F (around 18°C) usually gives more even germination than a warm shelf over a heater.
- Do not overseed. Extra seed does not speed anything up; it only crowds the tray and holds moisture at the base during the long grow.
- Keep notes. Write down your seed weight, soak time and harvest day. Cilantro lots vary, and two or three trays of notes will tell you the best rate for your seed.
Frequently asked questions
How long do cilantro microgreens take to grow?
Usually 15–21 days from sowing: about 6–9 days covered and 8–12 days under light. Cool rooms and whole seed push it toward the longer end.
Can I use coriander seeds from my spice rack?
Sometimes, but results are unreliable. Culinary coriander may be old or heat-treated, and it is not produced as seed for sprouting. Test a pinch on a damp paper towel first, and buy seed sold for microgreens for regular growing.
Do cilantro microgreens taste like cilantro?
Yes, though the seed leaves are milder. The flavor becomes more like the mature herb once the first true leaf appears.
Do cilantro microgreens regrow after cutting?
Not reliably. Most seedlings do not regrow after their growing point is cut, so sow a new tray. Read do microgreens regrow? for more.
Cilantro is not a beginner’s first crop, but with split seed, steady moisture and a cool room it becomes predictable. If you are new to microgreens, start with our guide on how to grow microgreens and add cilantro once your first trays succeed.
