Microgreens at Home: 10-Day Harvests on Your Countertop

Microgreens are the fastest path from seed to plate in any kind of indoor growing. Most varieties go from dry seed to harvest in 7–14 days, you don't need a grow light for the easy ones, and a single tray costs less than $2 to produce.

What you actually need

• Two 10x20 trays (one with drainage holes, one without).
• An inch of coco coir, peat, or a hemp grow mat.
• Seeds rated for microgreens (much cheaper per ounce than packet seeds).

The 10-day routine

Day 1: Soak seeds 6–8 hours (skip for tiny seeds like broccoli).

Days 1–3: Spread seeds densely on damp medium, cover with the second tray for darkness, and mist twice daily.

Day 4: Uncover. Move to a bright window or under a basic LED.

Days 5–9: Water from below by pouring into the bottom tray. Never mist the leaves once they're up.

Day 10: Cut just above the soil line with scissors.

Best beginner varieties

• Radish — explosive growth, peppery kick.
• Pea shoots — sweet and tendril-y; great in stir fries.
• Broccoli — mild flavor, packed with sulforaphane.
• Sunflower — nutty, crunchy, the "gateway green."

The most common failure

Mold. It's almost always caused by too much misting after germination, poor airflow, or seeds spread too thickly. Use a small clip-on fan and water from below — problem solved.

A two-tray rotation that gives you greens every weekend

The trick to a steady microgreens habit is overlap. Sow tray A on Saturday morning, tray B on the following Wednesday. By the time tray A is ready to cut on day 10, tray B is already uncovered and three days from harvest. You replant the empty tray immediately and the rotation self-sustains indefinitely from two trays and a single shelf of light.

The mold prevention rules that actually work

Mold is the single most common reason beginners abandon microgreens after one tray. Three interventions, in priority order:

• Water from below, never from above. Misting after germination is the leading cause of fuzzy seedlings.
• Put a small clip-on fan on a timer. Four hours a day of gentle airflow drops mold incidence to nearly zero in our trials.
• Sow less densely than you think. Crowded trays trap humidity around the seed coats and create the perfect mold environment.

What microgreens cost versus what they sell for

A 10x20 tray of broccoli microgreens uses roughly 30 g of seed (£0.90), one hemp mat (£0.40) and a splash of water. It harvests around 250 g of cut greens — which retail in UK supermarkets for £20+ per kg. The maths is the reason a lot of small market-garden businesses start here.

Frequently asked questions

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