"Sow on a windowsill, cut in a week, sell." For home use — yes. For commercial production — no. Between "it grew" and "the right quantity, the right quality, ready at the right time, consistently" lies a gap that only understanding the cycle can bridge. Every stage from seed preparation to harvest has its own parameters, and deviations at any one of them hit yield, quality, or product safety.
Quick Glossary
- Growth cycle — the full period from seed preparation to harvest; crop-dependent, typically 7–21 days
- Sowing — even distribution of seed across the substrate at the correct seeding rate; density determines yield and quality
- Harvest (cut) — collecting microgreens at the stage of fully open cotyledons or first true leaves; timing determines flavour, yield, and shelf life
Cycle Stages and What Each One Determines
Seed preparation. Some crops require soaking before sowing — sunflower, pea, beetroot, corn. Soaking accelerates germination and evens out emergence. Soaking time: 4–8 hours for most crops, no longer — otherwise seeds begin to suffocate. Seeds with a mucilaginous coating (basil, flax) are not soaked — they will clump and cannot be sown evenly.
Sowing. Even density across the entire tray is the foundation of uniform emergence and consistent yield. Uneven sowing produces bare patches where the substrate dries out, and dense clumps where mould appears. Seeding rate is different for every crop and is calculated — not estimated by eye.
Germination in darkness. Most crops are covered after sowing and kept in darkness for 2–4 days. The darkness and pressure from a lid or inverted tray forces seedlings to stretch upward and form a strong hypocotyl. Without this stage, seedlings are weak and prone to lying flat — they look poor and are harder to sell.
Growing under light. Once the seedling loops appear, trays are uncovered and moved under lighting. DLI (daily light dose) for most microgreens: 10–16 mol/m²/day. Too little light produces pale, elongated seedlings. Too much — growth suppression and dry leaf edges.
Harvest. The optimal moment: fully open cotyledons, even colour, first true leaves just beginning to emerge. A late cut means poorer flavour, shorter shelf life, and a higher risk of yellowing during storage. An early cut means underweight yield and underdeveloped flavour.
What Separates a Commercial Cycle from a Home Grow
At home: one tray, one crop, the result is needed "at some point." In commercial production — a continuous flow: a new batch starts every day or every other day, and a finished batch ships every day. This means the cycle must be synchronised: knowing exactly how many days each crop takes, planning sowing schedules in advance, and maintaining stable conditions so the cycle stays predictable.
Temperature, humidity, lighting, and irrigation are the parameters that affect cycle length. At 20°C radish is ready in 7 days; at 16°C it takes 10. If conditions change, the shipping schedule changes with them.
Three Mistakes That Cost the Most
Not calculating the seeding rate — sowing by feel. Too sparse a sow: underweight yield per tray, exposed substrate dries out. Too dense: seedlings stick together, suffocation, mould in the lower layer. The seeding rate for each crop is calculated once and recorded — then simply followed.
Cutting all crops on a fixed calendar day. "Sowed Monday — cutting in 10 days." But sunflower at higher temperature is ready in 8 days, and in cooler conditions in 12. Cutting by the calendar rather than by plant condition produces either an under-developed or an over-mature product.
Ignoring temperature and humidity after harvest. Microgreens after cutting are a living product that continues to "breathe" and age. Above 8°C shelf life drops sharply. From cut to refrigeration — maximum 30 minutes. This is not overcaution; it is the difference between 5 and 10 days of shelf life for the buyer.
How to Know the Cycle Is Set Up Correctly
- Emergence is even across the entire tray with no bare patches or over-dense zones
- Seedlings stand upright with uniform colour
- Harvest happens on the planned day plus or minus one day, regardless of which batch
- Tray yield is consistent from cycle to cycle with no more than 10–15% deviation