Microgreens indoors — 7-day harvest setup + 10 varieties

Microgreens indoors — 7-day harvest setup + 10 varieties

Microgreens are the highest-yield, fastest-payoff indoor garden you can grow — the edible counterpart to a sunny-sill indoor herb garden, and a far quicker return than hydroponic vegetables. A 25 by 25 cm tray produces 100 to 200 grams of harvest in 7 to 14 days — the equivalent of $5 to $10 of supermarket microgreens for about 30 cents of seeds and a minute of effort a day. They also pack 4 to 40 times the nutrient density of the mature vegetable they come from (broccoli microgreens have ~100x the sulforaphane of mature broccoli, per Johns Hopkins research). This guide is the bare-minimum setup, the 10 varieties that actually work indoors, the day-by-day timeline for each, the harvest technique, and the troubleshooting fixes for the three things beginners always get wrong (too-wet trays, too-thin sowing, too-late harvest). Days-to-harvest cross-referenced with USU Extension, Mississippi State Extension, and 2026 specialist growers.

Try Growli: Tag your microgreen tray in the Growli app. The app tracks each tray's sowing date, sends a reminder to remove the blackout cover on day 3 to 4, and tells you when to harvest based on the variety and visual cues you upload. The conversational AI also troubleshoots — upload a photo of mouldy seeds or leggy sprouts and it diagnoses the cause.

Why microgreens are the best beginner indoor garden

• Speed: 7 to 14 days from seed to harvest. Every other indoor garden category takes months.
• Yield: 100 to 200 grams per 25 by 25 cm tray, often more. A single tray produces what you would otherwise spend $5 to $10 on at the supermarket.
• Reliability: Densely sown microgreens have a 90+ percent germination rate. Failures are obvious within 3 days, so you lose only 3 days when something goes wrong.
• Space efficient: Trays stack vertically. A single shelf produces enough microgreens for daily use by a household of 2 to 4.
• No transplanting, no repotting, no long-term care. Plant, grow, harvest, restart.
• Nutrient density: Broccoli microgreens contain roughly 100 times the sulforaphane of mature broccoli. Red cabbage and red radish microgreens are similarly dense in protective phytochemicals.

The 10 best microgreen varieties for beginners

Match the variety to your patience and your palate. Days-to-harvest assume 18 to 22 °C and adequate light.

1. Radish — 5 to 7 days

The fastest microgreen and one of the most beginner-forgiving. Big seeds (easy to handle), high germination rate, peppery flavour. Varieties: Daikon, China Rose, Rambo (purple). Harvest at the cotyledon stage when leaves are 4 to 6 cm tall.

2. Broccoli — 7 days

Mild flavour, dramatic nutrient density. Tiny seeds — sow densely (1 to 2 tablespoons per 25 by 25 cm tray). Harvest when cotyledons are fully open and first true leaves just emerging.

3. Kale — 8 days

Sweet, mild, slightly cabbage-like. Tiny black seeds. One of the most reliable for beginners. Harvest at cotyledon stage; tastes earthier if left to true-leaf stage.

4. Mustard — 7 to 10 days

Sharp peppery flavour. Red Giant mustard adds dramatic colour to mixed harvests. Faster to flower than other brassicas, so harvest on time.

5. Arugula (rocket) — 7 to 10 days

Classic peppery salad green. Slightly slower than radish. Use 1 to 2 tablespoons of seeds per 25 by 25 cm tray.

6. Beet — 10 to 14 days

Sweet earthy flavour, striking red stems. Soak seeds overnight before sowing — beet seeds are actually seed clusters and germinate better after soaking. Harvest at first true leaves for best colour.

7. Basil — 14 to 21 days

The slowest microgreen on this list but worth it for flavour. Sow on a moist mat or directly into damp seed-starting mix (mucilaginous coating means basil sticks to fingers). Harvest at true-leaf stage.

8. Pea shoots — 10 to 14 days

Sweet, crunchy, tender. Big seeds — soak overnight before sowing. Sow densely and harvest when shoots are 8 to 12 cm tall. Pea shoots regrow once for a second harvest if you cut above the lowest leaf node.

9. Sunflower — 10 to 14 days

Crunchy, nutty, substantial. Big black oil seeds — soak 8 to 12 hours, then drain and rinse twice daily for another 24 hours before sowing. Heavy blackout weight on top of the seeds (a second tray with a brick on it) improves sprouting consistency.

10. Cress — 5 to 7 days

The traditional kindergarten microgreen. Tiny seeds, peppery flavour, near-100 percent germination. Mucilaginous (sticky when wet) — easier to sow on a hemp mat than in soil.

Mixed varieties — the "spicy mix" approach

Most seed retailers sell pre-mixed microgreen blends — "spicy salad mix" (radish + mustard + arugula), "rainbow mix" (radish + amaranth + kohlrabi), "Asian mix" (mizuna + tatsoi + mustard). Convenient for beginners but harvest timing becomes a compromise (faster greens are slightly overgrown by the time slower greens are ready). Better to grow single varieties in separate trays and mix at harvest.

Materials list — what you actually need

Total setup cost: $30 to $60 for a 3-tray rolling production system.

Trays

• 10 by 20 inch (~25 by 50 cm) growing trays — the standard size. Buy with and without holes. The drilled tray goes inside the un-drilled tray (the un-drilled outer tray catches drainage water). $2 to $5 each.
• Brands: Bootstrap Farmer (US, premium reusable), Bootstrap Farmer also ships UK, generic seedling trays from any garden centre. Avoid flimsy disposable cell trays — they crack within 2 to 3 uses.

Substrate (pick one)

• Sterile seed-starting mix — peat-free if possible. $5 to $10 per bag. Brands: Espoma Organic Seed Starter (US), Westland Seed and Cutting Compost (UK).
• Coco coir blocks — compressed, expand 5x in water. Cheaper per tray than bagged mix. $5 for a brick that does 4 to 6 trays.
• Hemp microgreen grow mats — soilless, hydroponic, hassle-free. Cut to tray size. $10 to $15 for a pack of 10 mats. Better for slimy-seeded varieties (basil, cress) that stick to soil.
• Burlap or jute mats — biodegradable, work for most microgreens. $10 to $15 for a pack.

Seeds — buy in bulk

Microgreen-specific seeds are sold in larger quantities (50g, 250g, 1kg) at much better per-gram pricing than supermarket seed packets.

• True Leaf Market (US) — the largest specialist microgreen seed retailer. Verified operating May 2026.
• Johnny's Selected Seeds (US) — wider variety range.
• Sky Sprouts (UK) — UK microgreen-specific. Verified operating May 2026.
• Sutton Seeds and Thompson & Morgan (UK) — wider range, includes microgreen-suitable varieties.
• Eden Brothers (US/global shipping) — large variety.

Verify seeds are sold for sprouting / microgreen use rather than garden seed (some garden seeds are treated with fungicides that should not be eaten).

Light

• South or west window with 6+ hours of direct sun: sufficient on its own for most microgreens.
• East window or partial sun: add a small LED grow light for the last 5 to 8 days. Same brands as our indoor herb garden setup guide — GooingTop clip-on ($25), Barrina T5 tubes ($30 to $45 for 4-tube pack), Mars Hydro TS600 ($60 to $80).
• No window: dedicated LED grow shelf required. Spider Farmer SF1000 or AC Infinity Ionboard S22 over a 2-tray rack works well.

Other essentials

• Spray bottle for misting young seedlings — $3 to $5.
• Sharp scissors or single-edge razor for harvest — $5 to $10.
• Small kitchen scale for measuring seed amounts — $10 to $15.
• Permanent marker and labels to track tray sowing dates.

Step-by-step setup — your first tray

A radish microgreen tray from day 0 to day 7. Identical process for broccoli, kale, mustard, arugula. Soaked-seed varieties (pea, sunflower, beet) add an extra day for the soak.

Day 0 — sow

1. Fill the inner (drilled) tray with 2 to 3 cm of moist seed-starting mix or place a pre-wetted hemp mat. Press flat with a second tray to level the surface.
2. Sprinkle 1 to 2 tablespoons of radish seeds evenly across the surface. The seeds should be touching but not piled — you want one seed thick, with virtually no soil showing through.
3. Mist generously with a spray bottle.
4. Cover with a second tray (the blackout cover) flipped upside down on top, with a brick or 2 kg weight on top to apply gentle pressure. This forces the seeds to develop strong roots before reaching for light.
5. Place somewhere warm (18 to 22 °C). The kitchen counter or a shelf is fine.

Days 1 to 2 — germinate in the dark

The blackout cover stays on. Lift it once daily to mist if the substrate looks dry. Roots should be visible within 24 to 48 hours.

Day 3 — uncover

Remove the blackout cover. Sprouts will be pale yellow and stretched (this is normal, called etiolation in microgreens). Move to bright indirect light or under a grow light.

Mist the surface daily, or bottom-water by pouring 1 to 2 cm of water into the outer (un-drilled) tray and letting the inner tray soak it up. Bottom-watering is preferred for the last few days — keeps the leaves dry, reduces disease risk.

Days 4 to 6 — greening up

Within 24 hours of light exposure, the sprouts turn from pale yellow to bright green. They straighten up and the cotyledon (seed leaves) fully open.

Continue bottom-watering. Keep the substrate consistently damp but not soggy. The substrate should feel like a wrung-out sponge.

Day 7 — harvest

When cotyledons are fully open and bright green, harvest. Use sharp scissors or a single-edge razor to cut just above the soil line. Hold a small handful of leaves in one hand, cut at the base, drop into a colander or bowl.

Rinse gently in cold water. Dry on a clean tea towel or in a salad spinner. Refrigerate in an airtight container with a paper towel — they keep 5 to 7 days.

Day 7+ — restart

Compost the spent substrate (or rinse hemp mats for reuse, though most growers compost). Clean the trays. Sow the next tray.

For a continuous harvest, sow a new tray every 3 to 4 days so you always have one approaching harvest.

Soil vs hydroponic — which method

Soil method (seed-starting mix)

• Pros: higher yields per tray, faster growth, works for all microgreen varieties including the slow-rooted ones (basil, cress).
• Cons: substrate cost per tray, soil sticks to harvest (rinse carefully), spent substrate needs disposal.
• Best for: beginners, high-yield production, anyone growing more than 3 to 5 trays a week.

Hydroponic method (hemp / jute / burlap mats)

• Pros: no soil at harvest, cleaner final product, mats are reusable for 2 to 3 cycles, no substrate disposal.
• Cons: lower yields per tray (10 to 20 percent less than soil), mucilaginous seeds (basil, cress) stick less well, sunflower and pea shoots underperform.
• Best for: kitchens that hate soil mess, restaurant-style presentation, anyone running into pest issues with soil method.

Hydroponic countertop systems

• AeroGarden units double as microgreen growers though they are designed for herbs. Pod-based, lower per-tray capacity. Verified operating May 2026.
• IDOO Indoor Garden can grow microgreens in dedicated tray inserts. Verified operating May 2026.

Most commercial microgreen growers use trays + hemp mats or trays + sterile mix. The countertop hydroponic units are convenient for tiny kitchens but produce far less harvest per dollar spent.

Care after sowing — the daily routine

Total daily time after the initial sow: under 1 minute.

• Days 1 to 2 (blackout): lift cover once, mist if dry, replace cover. 20 seconds.
• Day 3 (uncover): remove blackout cover, move to light. 20 seconds.
• Days 4 to 6 (light): check water level in outer tray, top up if low. 20 seconds.
• Day 7 (harvest): cut, rinse, dry, store. 10 to 15 minutes.

Per tray total: 20 to 25 minutes across 7 days. Per gram of harvest: about 0.2 minutes — dramatically faster than any other indoor garden category.

Troubleshooting microgreens

Seeds did not germinate. Three causes. Seeds too old (older than 2 to 3 years for most species — buy fresh). Substrate too dry (mist twice daily during germination). Substrate too cold (under 15 °C slows germination dramatically — move to a warmer spot).

Some seeds sprouted, most did not. Inconsistent sowing density. Re-sow more evenly next time, aiming for a single layer of seeds in contact with the substrate.

Mould on the seeds or substrate. Three causes. Too wet (back off misting, switch to bottom-watering). Poor airflow (uncover the tray and place near gentle air movement). Seeds too dense (some growers report mould on 3+ layers of seeds piled on top of each other). White fuzz on roots is often root hair, not mould — distinguishable because it appears only on the roots, not on the substrate.

Leggy pale sprouts. Not enough light after blackout removal. Move closer to a window or under a grow light. Microgreens at this stage need 12 to 16 hours of bright light daily.

Sprouts collapsing (damping off). Fungal infection from over-wet substrate or contaminated seeds. Compost the tray. Sterilise trays with diluted bleach (1:10) before next sow. Use sterile seed-starting mix, not garden soil.

Bitter or unpleasant flavour. Harvested too late. After true leaves develop, microgreens shift from sweet to bitter as the plant moves into vegetative growth. Harvest at cotyledon stage or just as the first true leaves emerge.

For broader indoor pest patterns see houseplant pests identification and fungus gnats.

Advanced moves — production scaling

• Tray rotation system: sow a new tray every 3 days for a continuous harvest. 4 trays in rotation = a fresh harvest every 3 days.
• Vertical shelves: wire racks or repurposed bookshelves with grow lights on each shelf. A 4-shelf wire rack hosts 8 to 12 trays — enough for daily microgreen use by a family.
• Reusable hemp mats: rinse used mats thoroughly, dry, and reuse for 2 to 3 cycles. Reduces consumable cost over time.
• Selling at farmers' markets: small commercial microgreen operations sell at $4 to $8 per 50g pack. A 4-shelf setup producing 20+ trays a week can generate meaningful side income. Check local cottage food laws and food safety requirements first.
• Combine with seed sprouting: alfalfa, mung bean, lentil sprouts (eaten with seed and root, no soil) are a different but related indoor crop. See seed starting indoors for the broader seed-starting context.

Related

• Seed starting indoors — broader seed-starting principles
• Indoor herb garden setup — companion indoor edible setup
• Indoor garden setup — broader gear and 30-day plan
• Easiest vegetables to grow — scaling up beyond microgreens
• Container vegetable gardening — when you want bigger crops
• Types of vegetables — broader vegetable taxonomy
• Types of lettuce — related fast-growing salad crops
• Types of soil — substrate options
• How to grow basil — companion herb growing
• Houseplant pests identification — broader pest matrix
• Fungus gnats — the main microgreen pest
• Pot size calculator — sizing trays and pots
• Light meter guide — measuring microgreen tray light

Microgreen days-to-harvest cross-referenced with Utah State University Extension, Mississippi State University Extension, Oregon State Extension, and 2026 specialist growers True Leaf Market and Sky Sprouts. Nutrient density data from Johns Hopkins Bloomberg School of Public Health sulforaphane research. Brand availability (True Leaf Market, Sky Sprouts, Bootstrap Farmer, Eden Brothers, AeroGarden, IDOO) verified May 2026.