Growing microgreens: harvest in ten days
Microgreens are young seedlings harvested as the first true leaves appear. They need no depth, no sun and no season: a shallow tray, a spot on a shelf and ten days. For anyone growing indoors who wants to harvest something in December too, this is the most reliable option in the guide.
At a glance
- Light
- Little — a bright window or a simple grow light
- Pot depth
- Tray 4 to 5 cm, no deeper
- Sowing
- All year round, a new tray weekly
- Harvest
- 7 to 14 days after sowing
- Water
- Mist with a spray bottle, never pour
- Level
- Very easy
Seed and tray
Use seed intended for eating: radish, rocket, pea, sunflower, broccoli, cress. Buy seed sold as microgreen seed where you can — ordinary garden seed is sometimes treated with products you would rather not eat raw.
A tray four to five centimetres deep is enough; deeper serves no purpose because you harvest before real roots form. Sow far more densely than you are used to: the seeds may almost touch.
The dark start
Cover the tray for the first three to four days with a lid or a second tray. In the dark the seedlings stretch and germinate more evenly.
Remove the cover once most seeds are up. The leaves will be pale yellow and turn green within a day in the light.
Water and mould
Mist with a spray bottle rather than pouring. Pouring washes seeds away and leaves puddles in the base, which is exactly where mould starts.
White fuzzy threads are usually root hairs rather than mould — they vanish when touched. If it stays sticky and smells musty, there is too little air movement: add a small fan and sow more thinly.
Harvesting
Cut just above the compost as the first true leaves unfold, usually between day seven and fourteen. Wait longer and the stems toughen.
Microgreens do not regrow: after cutting, compost the layer and sow again. Two trays sown a week apart give a continuous harvest.
Frequently asked questions
Do microgreens need a grow light?
Not necessarily. A bright window is enough, north-facing included. To keep the same speed in December, a simple ten to twenty watt lamp speeds things up noticeably.
Can I just use ordinary garden seed?
Preferably not. Regular seed is sometimes treated against fungus, which is fine for plants you cook later but not for leaves eaten raw. Seed sold as microgreen seed is checked for this.
Do microgreens regrow after harvesting?
No. Apart from pea shoots, which sometimes resprout once, one harvest per sowing is the rule. Sow a new tray weekly instead.
Updated on 2026-08-25
Plan it in Cropsy
Cropsy works out pot depth, light and sowing dates for your own spot and puts the reminders in your calendar.
Discover Cropsy