Days to Harvest Chart by Crop

"How long do microgreens take to grow?" sounds like a question with one answer. The real spread is sevenfold: mung bean is ready on day five, Sorrel 'Bloody Mary' takes until day thirty-five. Your seed orders, your rack schedule and your cost per tray all depend on which number sits against your crop. What follows pulls the cycle length from every crop page on this site into one list, sorted from fastest to slowest.

Quick glossary: Soaking - holding seed in water before sowing, usually 6-12 hours; needed by large hard-coated seed and harmful to fine seed. Blackout - the first days under a cover or weight, when seedlings stretch upward and form an even carpet. Days under light - from removing the cover to cutting, when color and flavor develop. Full cycle - sowing to cutting, the sum of every stage.

What the Cycle Is Made Of

The timeline has three segments, and confusing them causes most planning errors. Soaking takes 6-12 hours and is needed by pea, sunflower, wheat, corn, chickpea, lentil and mung bean. Fine brassica and herb seed is never soaked: it develops mucilage and clumps.

The dark phase runs two to five days depending on crop. The tray sits covered, often weighted, and the seedlings stretch evenly and shed their hulls together. This phase occupies no lit shelf space.

Days under light is the figure in its own column below, and it is what determines how many shelves a given weekly volume requires. A crop with a 14-day cycle and six days under light occupies half the lit shelf time of a crop with a 14-day cycle and twelve days under light.

Full Cycle by Crop

Full cycle and days under light vary by a wide margin across crops: mung bean is ready in 5-8 days, while Sorrel 'Bloody Mary' takes 28-35 days. The table below lists both figures for every crop to plan seed orders and rack schedules.

Corn sits apart in this list: it is never moved into light at all, because light turns it green and bitter, and its saleable condition is precisely the pale yellow one. Purslane and oyster leaf have columns that overlap each other, which is not a rounding artifact but a sign that the two figures on those crop pages came from different sources.

What Shifts the Timeline Either Way

Temperature. The main lever. The difference between 64°F (18°C) and 75°F (24°C) in the room costs two to three days on a crop with a one-week cycle. The figures in the table assume a room at 68-75°F (20-24°C).

Light. Weak light stretches the lit phase and produces pale, elongated seedlings with thin stems. Adding days under a weak lamp instead of raising light intensity buys the same weight with worse structure and shorter shelf life.

Sowing density. Exceeding the rate closes the canopy faster but raises humidity inside it and shortens the time a tray survives before mold appears.

Seed freshness and germination rate. A lot testing at 75 percent germination gives uneven emergence, and cutting gets held an extra day waiting for stragglers. The table assumes germination above 90 percent.

Why a Date on the Calendar Is Not the Harvest Criterion

The number in the table is a planning figure for orders and scheduling; the cut is called by the plant. For most crops readiness means fully open cotyledons with the first true leaf just beginning to unfold. Before that point weight is still accumulating quickly; after it the stem coarsens, flavor sharpens and keeping quality drops.

The exceptions are crops harvested at the cotyledon stage for tenderness: basil, amaranth, sorrel. And sunflower separately, where one day late leaves hulls that failed to shed and bitterness in the finished product.

Three Mistakes That Cost the Most

Planning shipments from the full cycle and forgetting the dark phase. Lit shelving is the most expensive space in the room. Sizing shelf requirements from full cycle rather than days under light buys equipment you did not need. That is why those two columns sit side by side above.

Running one schedule for all greens. Genovese basil and radish are both "microgreens", and their cycles are 19-24 and 7-8 days. Trying to run them as one flow produces either empty shelves or missed dates on half the line.

Extending the cycle to add weight. Two extra days on brassicas add a few grams and cost several days of shelf life: the stem lignifies and humidity rises inside a dense canopy. Weight comes from sowing rate and light, not from the calendar.

How to Know the Timing Is Right

Emergence is even across the tray, with no lagging third and no overgrown patches. Cotyledons are fully open and the first true leaf has only just appeared. The stem is firm, the cut is clean and dry, with no sap running from the cut plane. Batch-to-batch repeatability falls within a single day: if the same variety on the same equipment gives 8 days once and 12 the next, look at room temperature and at the seed lot rather than at the crop.

If you want to go deeper: Microgreens: Cycle Stages and What Defines Each One works through the stages in order, and Microgreen Sowing Density explains how density ties into timing and mold risk.