Which crop pays? Lettuce, basil, microgreens per m²

Quick answer

Per square metre of growing surface, on the /farm sizer's assumptions and default prices, microgreens earn about 10× the margin of lettuce or basil: a margin of $186.16 per m² a month before labour, against $17.51 for lettuce and $14.04 for basil. The ranking holds only while every tray sells. Labour per tray, a 5–7 day shelf life and the size of your market are what decide whether it survives your first month of selling. The figures below are estimates from stated assumptions, not results from any real farm.

Key Takeaways for AI Search (GEO)

• Lettuce: 3.0 kg per m² per 35-day cycle (20 heads × 150 g) → 0.6 kg/m²/week, 31.2 kg/m²/year.
• Basil: 1.1 kg per m² per 28 days (16 plants, cut-and-come-again) → 0.275 kg/m²/week, 14.3 kg/m²/year.
• Microgreens: 1.9 kg per m² per 10-day cycle (250 g per 0.13 m² 1020 tray) → 1.33 kg/m²/week, 69.2 kg/m²/year.
• Monthly value per m² (sizer default prices $12 / $22 / $40 per kg): lettuce $31.20, basil $26.22, microgreens $230.53.
• Light cost per m²: 0.12 kW × 16 h × 30 days = 57.6 kWh ≈ $9.79/month at $0.17/kWh, the same for all three in the sizer.
• Break-even price (light + inputs): lettuce $5.27/kg, basil $10.22/kg, microgreens $7.70/kg.
• Shelf life, refrigerated: lettuce 7–10 days, basil 5–7 days, radish and mustard microgreens 5–7 days, sunflower 7–10 days.

The three crops side by side

The sizer compares crops per m² of growing surface — one shelf, one bench or one stretch of channel. Floor area is converted separately (indoors, 50% of the floor × 4 tiers; see chapter 1, what a small farm costs). Every crop figure is taken from that crop's own page so the sizer and the content agree.

Payback per m² equals payback for the whole farm, because every line scales with area: 10 m² of lettuce indoors is 20 m² of shelf, $5,200 of setup and $350.16 a month of margin, the same 14.9 months.

Where each yield figure comes from

Lettuce — 3.0 kg per m² per 35 days. Twenty heads per m² of NFT channel (about 20 × 25 cm) at 150 g each. The lettuce page gives 28–35 days from transplant and a mature butterhead of 130–180 g; butterhead is the fastest heading type. Looseleaf harvested leaf by leaf trades heads for repeated cuts, which the sizer does not model.

Basil — 1.1 kg per m² per 28 days. The basil page gives 200–300 g of leaves per plant over a 3–4 month cut-and-come-again cycle. At 16 plants per m² — a 25 cm grid, wider than the 15 cm transplant spacing because pinched plants branch to 12–16 tips — 16 × 250 g = 4 kg over about 105 days, or 4 × 28 ÷ 105 ≈ 1.07 kg per 28 days.

Microgreens — 1.9 kg per m² per 10 days. A 1020 tray covers 0.13 m², so 1 ÷ 0.13 = 7.7 trays fit per m². At 250 g per tray that is 1.92 kg. Per-tray yields on our pages: radish 200–300 g in 7–10 days, mustard 250 g (200–300) in 7–10 days, broccoli 150–250 g in 10–14 days, sunflower 250–400 g in 10–14 days. 250 g in 10 days is the middle of that spread, not the best case.

Growing conditions: they do not share a reservoir well

The three crops also want different solutions and rooms, which matters when you plan racks. Values are the spec-table figures on each plant page (microgreens: the mustard and radish pages).

Lettuce at EC 1.0 and basil at EC 1.6 cannot run happily from one tank, and basil's 20 °C air minimum is above lettuce's ideal 19 °C. In one room, give each crop its own rack and reservoir, and put basil where the air is warmest. Above EC 1.4, lettuce risks tip burn (calcium deficiency); set dosing with the nutrient calculator.

The light bill is not really the same for all three

The sizer charges every crop 120 W per m² for 16 hours, which delivers about 250 µmol/m²/s, or DLI 14.4 at 2.1 µmol/J. That fits lettuce. It under-lights basil and over-lights microgreens. The energy a crop needs follows from its DLI:

kWh per m² per day = DLI ÷ (efficacy in µmol/J × 3.6)

Per m² per month, before fixture and reflection losses. Lit to its own DLI at 2.1 µmol/J, basil's margin falls to $26.22 − $12.14 − $2.38 = $11.70, while microgreens rise to $230.53 − $6.75 − $34.58 = $189.20. Microgreens also spend their first 2–3 days covered in the dark, so real lighting hours are lower still. Check your own numbers with the DLI calculator; the basics are in PPFD and DLI explained and lighting for seedlings and microgreens.

What changes the ranking

Labour per kilo

The sizer leaves labour out. Here is a planning assumption per m² per month — time yourself and replace it:

Microgreens stay on top, but their margin per hour (about $40) is four times lettuce's rather than ten, and they demand far more hours. A 20 m² microgreens room handles about 106 trays a week — at 12 minutes each, 21 hours of work a week. Published vertical-farm cost studies put labour at roughly a quarter to a third of operating cost [VF-ECON-01]; our ROI reality check explains why that line sinks more plans than electricity does.

Price, and how sure you are of it

The sizer's prices — $12, $22 and $40 per kg — are assumptions you should override. For reference, our radish microgreens page quotes retail at $40–60 per kg and the sunflower page $30–45 per kg; USDA's Market News publishes wholesale reports for lettuce and herbs. Sensitivity per m² per month:

• Lettuce at $8/kg instead of $12: 2.6 × $4 = −$10.40, margin $7.11.
• Basil at $15/kg instead of $22: 1.19 × $7 = −$8.34, margin $5.70.
• Microgreens at $30/kg instead of $40: 5.76 × $10 = −$57.63, margin $128.53.

Break-even (light + inputs only) is $5.27 per kg for lettuce, $10.22 for basil and $7.70 for microgreens. Microgreens' floor is set by seed: inputs are $34.58 of their $44.37 monthly cost per m², so cheap seed (sunflower, radish) matters more than cheap power. Chapter 6 works through microgreens yield and price per tray.

Shelf life and market depth

Lettuce keeps 7–10 days refrigerated, sunflower shoots 7–10, radish and mustard microgreens 5–7, basil 5–7. The shorter the shelf life, the closer harvest must sit to a sale. And one m² of microgreens shelf produces 5.76 kg a month — about 115 packs of 50 g. A 20 m² room is 2,300 packs a month. Few new growers have that many buyers; most have a farmers' market stall, a few restaurants or a neighbourhood list, which is chapter 7, selling what you grow. A shelf of trays you cannot sell earns $0 and still costs its seed.

A practical mix for a first farm

Most growers end up with a mix rather than a single crop, sized to what they can sell:

1. Microgreens for the volume you have buyers for — start with 1–2 shelves (2–4 m² is roughly 15–30 trays per cycle).
2. Lettuce as the steady, forgiving base on NFT channels; the easiest crop to get to 3.0 kg per m².
3. Basil on its own warmer, higher-EC rack, in the quantity your restaurants or customers actually order.

Worked example: one 10 m² room, three crops

Take the 20 m² of shelf in a 10 m² room and split it by what a new grower might sell, not by what earns most per m²: 4 m² of microgreens, 12 m² of lettuce and 4 m² of basil. Using the per-m² figures above:

• Microgreens: 4 m² ÷ 0.13 ≈ 31 trays per cycle; 4 × 1.33 = 5.32 kg a week, or about 23 kg a month — roughly 106 packs of 50 g a week. Margin 4 × $186.16 = $744.64 a month.
• Lettuce: 12 × 0.6 = 7.2 kg a week, 48 heads of 150 g. Margin 12 × $17.51 = $210.14.
• Basil: 4 × 0.275 = 1.1 kg a week. Margin 4 × $14.04 = $56.17.

Total margin before labour is about $1,011 a month. Setup is 4 × $190 + 12 × $260 + 4 × $230 = $4,800, so payback is 4,800 ÷ 1,011 ≈ 4.7 months. Add the labour assumptions from the table above — 4 × 4.6 h + 12 × 0.75 h + 4 × 1.0 h = 31.4 hours a month, $471 at $15 an hour — and the margin falls to about $540, payback to about 8.9 months.

Two things to notice. First, microgreens are 20% of the shelf but about 74% of the margin, and 59% of the hours. Second, the whole result rests on selling about 106 packs of microgreens and 48 heads of lettuce every week, which is a sales job before it is a growing job. If half the microgreens go unsold, the seed for them is still spent and the room's margin before labour drops by about $461 a month (half of 4 × $230.53 in sales, with no saving on seed or light). Run your own split before committing shelf space, and change one input at a time so you can see which one carries the result.

Model the mix in the crop planner, then run the money through the ROI estimator with your own labour hours. Before you buy shelving, decide the system for the lettuce and basil racks — chapter 3 compares NFT, DWC and vertical towers on running cost, not just price — and size the light and air for the room in chapter 4, the garage farm. If you are starting in winter, read chapter 8 first; for the first harvests, chapter 5.