How to Grow Microgreens Indoors

Microgreens are ordinary vegetable and herb seedlings harvested very young. They need a shallow tray, a thin layer of growing medium, seed, and a bright spot.

What you need

• A shallow tray, ideally with a second tray underneath
• Potting mix or a purpose-made growing mat
• Microgreen seed sold for this use
• A spray bottle
• Scissors for harvest

The basic method

1. Fill and level

Add a shallow, even layer of moist medium and press it flat. An uneven surface leads to patchy germination.

2. Sow densely

Microgreens are sown far more thickly than normal seedlings. Spread seed evenly across the surface rather than in rows.

3. Cover and wait

Many growers cover the tray for the first days to keep humidity steady, then uncover once sprouts appear.

4. Light and mist

Move the tray into bright light or under a grow light and keep the surface lightly moist, not soaked.

5. Harvest

Cut just above the medium when the first true leaves appear. Most trays are a single harvest; sow a new tray to keep a steady supply.

A ten-day microgreens cycle, step by step

• 1. Fill a shallow 8 x 12 inch tray with 1.5 inches of damp potting mix and level the surface with your hand — no need to firm it hard.
• 2. Sow densely: about 1-2 tablespoons of small seed such as radish, broccoli or mustard per tray, or 3-4 tablespoons of pea or sunflower seed, soaked overnight first.
• 3. Mist, then cover with a second inverted tray for blackout. Darkness for the first 2-4 days makes stems reach and lengthen evenly.
• 4. Mist once or twice a day under the cover; the seed must never dry out during germination.
• 5. Uncover once shoots are 1.5 inches and lift the sprouted mat. Move to a bright sill or 8 inches under an LED for 12-14 hours a day.
• 6. Water at the base of the tray from day five so the leaves stay dry — wet foliage is the main cause of mold.
• 7. Harvest at days 8-14 by cutting just above soil level with scissors. Rinse, dry well, and use within four to five days.

Reliable varieties and their timings

• Radish: 6-8 days, peppery, almost impossible to fail — the best first crop.
• Broccoli: 8-12 days, mild, popular for everyday use.
• Pea shoots: 10-14 days, sweet and crunchy; soak the seed 8-12 hours before sowing.
• Sunflower: 8-12 days, thick and nutty; rub the seed hulls off after harvest.
• Basil and cilantro: 14-21 days, slower and more demanding — try these third or fourth.

A real example: a rolling two-tray rotation

Two trays and a two-week rhythm give a continuous supply: sow tray A on day 1, tray B on day 7, harvest A around day 10 and resow it, harvest B around day 17. That cycle produces roughly a large handful of greens each week from a countertop area no bigger than a cutting board.