One tray · a few days · a repeatable system
How to Grow Microgreens
A detailed seed-to-harvest production guide for crisp, clean, uniform microgreens—whether you are growing one kitchen tray or building a weekly rotation.
Start with the right definition
Microgreens are their own crop
They are harvested above the growing medium after cotyledons open and, depending on the crop, as the first true leaf begins to appear. That makes their production and food-safety needs different from sprouts and baby greens.
Cut above the medium
- Grown in light after germination
- Usually harvested in 7–25 days
- Stem and leaves are eaten
Seed, root and shoot
- Usually water-grown in darkness
- Harvested earlier
- Different sanitation system
Older leaf crop
- Longer production cycle
- More spacing and fertility
- Often cut at multiple true leaves
Crop-specific weights—not seed-count guesses
Build your first tray
Select an individual microgreen crop and the calculator will scale a practical 10×20 tray seeding-weight range to your exact growing area. Record the final weight and yield so you can refine the rate for each seed lot and grow room.
Brassicas & radish
Reliable first trays with quick, even emergence.
- Soak
- Usually no
- Blackout
- Short
- Harvest
- Often 7–12 days
Pea & sunflower
Higher seed mass and a sturdier finished crop.
- Soak
- Often 8–12 hours
- Blackout
- Weight helps contact
- Harvest
- Often 9–16 days
Basil, dill & fennel
More patience, careful moisture and gentler handling.
- Soak
- Crop dependent
- Blackout
- Longer, monitor daily
- Harvest
- Often 14–30 days
Beet, chard & amaranth
Excellent stem color, with slower or more delicate emergence.
- Soak
- Crop dependent
- Blackout
- Moderate
- Harvest
- Often 10–20 days
A repeatable production rhythm
The eight-step tray cycle
Consistency comes from treating every tray like a batch: clean tools, measured seed, a dated label, daily observations and a recorded yield.
Clean & stage
Wash hands. Clean, then sanitize food-contact trays, tools and harvest surfaces. Start with new, clean medium.
Measure seed
Check germination, weigh the seed and record the lot. Sow one crop per tray unless growth rates truly match.
Soak selectively
Soak only crops that benefit, commonly larger hard seeds. Drain and rinse well; never let seed sit in dirty water.
Sow evenly
Level moist medium, distribute seed edge to edge and press for consistent seed-to-medium contact without burying deeply.
Blackout / weight
Cover to hold humidity during germination. Use a clean weight for crops such as pea and sunflower; inspect every day.
Uncover into light
When seedlings lift the cover and roots are established, move to bright, even light with airflow around—not blasting—the canopy.
Bottom water
Add clean water beneath the tray as needed. Keep foliage drier, avoid standing water and let roots breathe between irrigations.
Harvest & reset
Cut a dry canopy above the medium with a clean blade. Cool promptly, record yield, discard medium and restart clean.
Your grow-room dashboard
Control the environment, not the calendar
Food safety is part of the crop
Clean is a process, not an appearance
Microgreens are eaten raw and grown in a warm, moist environment. A tidy room helps, but documented hygiene and clean water matter more.
Seed & water
Use high-quality untreated, uncoated seed intended for edible production and potable water for soaking, irrigation and cleaning.
Clean, then sanitize
Remove soil and organic matter before applying a food-contact sanitizer at the labeled concentration and contact time.
Protect the crop
Keep animals, dirty tools, splashing water and standing water away. Handle trays and seed with clean hands.
Harvest dry
Use a clean sharp blade and cut above the medium. Avoid washing unless your validated process requires it; wet leaves store poorly.
Commercial growers should determine how the FDA Food Safety Modernization Act Produce Safety Rule applies to their operation and maintain appropriate records.
Diagnose the tray early
Common microgreen problems
Open a symptom to see the likely cause and the first correction to make.
Root hairs or mold?
Root hairs form an even halo directly around roots and often become less visible when wet. Mold bridges seeds, medium or stems in irregular webbing and may smell musty. Improve sanitation, density, airflow and moisture control.
Damping-off
Seedlings pinch or collapse at the media line. Discard affected trays, lower excess moisture and canopy humidity, clean the area and start the next batch with fresh medium.
Uneven germination
Check seed distribution, contact, tray level, temperature and germination percentage. Corners often dry first; overwatering can create equally uneven results.
Leggy, pale growth
Move uncovered trays into brighter, more even light sooner. Keep lights close enough for useful intensity without overheating the canopy.
Seed hulls cling
Maintain adequate germination humidity and even contact. For appropriate crops, gentle weighting helps; after emergence, a light brushing may release dry hulls.
Sour odor or slime
Stop and discard the tray. Review soak time, drainage, standing water, seed density and sanitation before sowing again.
Verified on the Urban Farmer Shopify store
Choose seed by tray behavior
Begin with contrasting crops so you learn how seed size, speed and canopy structure change your routine. These links go to exact microgreen seed products.
The fastest way to improve
Microgreen production log
Complete one line per tray. Within a few cycles you will have crop-specific rates for your room, equipment and customers. The gray example below is only a guide and will not appear on the printed log.
| Batch / crop | Seed lot | Seed wt. | Soak | Sow | Uncover | Harvest | Yield | Notes |
|---|---|---|---|---|---|---|---|---|
| MG-042 · Daikon | DR-2608 | 28 g | No | 9/1 | 9/4 | 9/10 | 11.5 oz | Even stand; uncover one day earlier next cycle |
Grower FAQs
Questions that change a tray
Do microgreens regrow after cutting?
Most are best treated as a one-cut crop. Regrowth is uneven, slower and more difficult to keep clean; restart with fresh medium for predictable quality.
Do I need fertilizer?
Many short-cycle crops rely largely on seed reserves. Longer crops or inert media may benefit from a carefully managed, crop-appropriate nutrient program, but excess fertility can reduce quality.
Can I mix seeds in one tray?
Only if germination, growth rate, blackout and harvest timing are compatible. For consistent production, grow crops separately and blend after harvest.
Which plants should not be microgreens?
Do not grow tomato, pepper, eggplant or potato seedlings as microgreens; their foliage contains undesirable alkaloids. Avoid unknown wild plants and treated seed.
How long do harvested microgreens keep?
Crop and handling matter. Cool, dry product promptly; Penn State reported roughly 10–14 days at about 41°F in dark storage versus only a few days at room conditions.
Should I wash before storage?
For home use, wash immediately before eating as appropriate. Postharvest washing adds moisture and may spread contamination unless it is part of a carefully controlled commercial process.