Microgreens Seed Density Chart: Grams per 1020 Tray

Seed grams per 1020 tray are the number that decides profit. Too light and the flat looks thin at the sale. Too heavy and you paid for seed the tray cannot stand up. The rate is per cultivar, not per "microgreen."

The nursery is indoor 1020 flats. It is not the outdoor 30-inch bed. The rack holds 31 cultivars. A 16-slot bay is the unit. Weigh the seed. Soak what should be soaked. Cut on the cycle.

Grams that change the tray cost

These are the sheet rates, one 1020, not a guess from a bag label.

Daikon radish is 60 grams. China Rose radish is 58 grams. Red Arrow radish is 55 grams. Waltham 29 broccoli is 40 grams. Red Acre cabbage is 35 grams. Astro arugula is 22 grams. Genovese basil is 18 grams. Dark Opal basil is 16 grams. Black chia is 24 grams. Curled garden cress is 20 grams.

Heavy seed is a different bill. Dwarf Grey Sugar pea is 280 grams. Speckled pea is 260 grams. Hard red wheat is 220 grams. Black Oil sunflower is 200 grams. Dehulled Black Oil is 180 grams. Common buckwheat is 150 grams. Bull's Blood beet is 45 grams. Bright Lights chard is 42 grams. Golden flax is 40 grams, and it is dry-sow. Lacinato kale is 30 grams. Red Russian kale is 32 grams.

A 4-tray Waltham 29 batch on the board is 160 grams of seed, cut at 40 ounces, wholesale $50.00. A 4-tray Daikon batch is 240 grams, cut at 48 ounces, wholesale $48.00. Same tray count. Seed weight is not the same, and the cut is not the same. Price the flat from the grams, not from the crop name. Density is the profit line. Weigh it.

Soak, or lose the tray

Basil, chia, flax, and cress never go in water. Wet seed turns to gel and you lose the tray. Dill is dry-sow on the card too. Red Garnet amaranth is dry-sow. Genovese, Dark Opal, and Mrs. Burns Lemon basil are dry-sow, under a dome, no weight.

The rest get a timed soak. Astro arugula, Waltham 29 broccoli, and Red Russian kale are cold water, 8–12 hours, then stacked under a paver. Red Giant mustard and the radishes are warm water, 4 hours, stacked. Bull's Blood beet, Bright Lights chard, peas, sunflower, and wheatgrass go overnight, 16 hours, stacked. Santo cilantro is cold water, 8–12 hours, under a dome, no weight.

The cycle

Most flats cut in 7–14 days. Curled cress is 7 days. Daikon is 7 days. China Rose and Red Arrow are 8 days. Astro arugula and Red Giant mustard are 8 days. Waltham 29 broccoli and Red Garnet amaranth are 10 days. Dwarf Grey Sugar pea is 12 days. Genovese basil is 14 days. Dark Opal basil is 16 days. Santo cilantro is 18 days. The 7–14 day band is the working cycle. Cilantro and onion greens sit outside it. Do not book them on a broccoli turn.

A queued Daikon batch sown 2026-10-04 cuts 2026-10-11. That is the 7-day cycle on the calendar, not a slogan. Turn the rack on that clock and a 16-slot bay refills every week. Book an 18-day cilantro into a 7-day slot and the bay is still full when the next sow shows up.