Short answer: most microgreens take 7 to 14 days. Days 0 to 3 are for soaking, sowing and blackout. Days 3 to 10 are under light with daily bottom watering. Harvest when the seed leaves are fully open: about day 7 to 12 for brassicas, 8 to 10 for sunflower and peas, and 14 to 25 for herbs.
How long do microgreens take to grow? Chart by crop
| Crop | Days to harvest | Speed |
|---|---|---|
| Cress | 8–12 | Fast |
| Broccoli | 7–12 | Fast |
| Mustard | 8–12 | Fast |
| Arugula | 8–12 | Fast |
| Turnip | 8–12 | Fast |
| Pea shoots | 8–10 | Fast |
| Sunflower | 8–10 | Fast |
| Radish | 10–12 | Fast |
| Kale | 10–14 | Medium |
| Buckwheat | 10–12 | Medium |
| Beet | 8–12 | Medium |
| Basil | 12–21 | Slow |
| Cilantro | 16–28 | Slowest |
| Parsley | 14–21 | Slow |
Times are typical for a room at 65 to 75°F (18 to 24°C) with good light.
How long microgreens take to grow, day by day
- Day0
Soak and sow
Soak big seeds like peas and sunflower for 4 to 8 hours. Sow small seeds dry. Spread seed evenly over 1 inch of moist soil or a grow mat, and mist it.
- Day0–3
Blackout
Cover the tray. Seeds swell and send out roots. Fine white root hairs often appear around day 2. Mist once or twice a day.
- Day2–4
Uncover
When seedlings push up the cover, take it off. Stems are pale yellow at first. They turn green within a day in good light.
- Day4–8
Green-up
Give 12 to 16 hours of light a day. Water from below once a day. Seed leaves open and stems firm up.
- Day7–12
Harvest brassicas, peas and sunflower
Cut just above the soil when the seed leaves are fully open.
- Day14–25
Harvest herbs and slow crops
Basil, cilantro, beet and parsley take longer. Keep them warm and watered.
What speeds microgreens up
- Warmth. About 65 to 75°F (18 to 24°C). Basil likes it warmer.
- Bright light after blackout. Low light means slow, leggy growth.
- Fresh seed. Old seed sprouts slowly and unevenly.
- Even moisture. Seed that dries out during blackout stalls.
What slows microgreens down
- A cold room. Below about 60°F (16°C), growth slows a lot.
- Low light. Especially in winter. See do microgreens need grow lights?
- Overwatering. Soggy roots grow slowly and invite mold.
Planning a steady supply
Because most microgreens take 7 to 14 days, sow a small tray every 3 to 5 days. That way one tray is always ready while the next is growing. The microgreens seeding chart shows seed rates for every crop.
When to harvest
Harvest when the seed leaves are fully open and before the first true leaves get large. Cut with sharp scissors just above the soil. See how to harvest microgreens for timing tips by crop.
New to growing? Read the step-by-step microgreens guide.
Frequently asked questions
What is the fastest microgreen to grow?
Cress, radish and mustard are among the fastest, often ready in 7 to 12 days. Broccoli is close behind.
Why are my microgreens growing slowly?
The most common causes are a cold room, too little light, or seed that dried out during blackout. Microgreens grow best at about 65 to 75°F (18 to 24°C) with bright light.
Can you harvest microgreens too early?
Yes. Before the seed leaves open, the greens are small and taste mostly of stem. Wait until the seed leaves are fully open.
What happens if you wait too long to harvest microgreens?
They grow true leaves, get tougher and often more bitter. Some crops, like sunflower, turn noticeably bitter. Others, like pea shoots, stay good a little longer.
Written by Michael
A passionate sprouting professional sharing practical tips for growing sprouts and microgreens at home. More about Michael
