The journey of a lettuce: four weeks, 23 litres and a 24‑hour window

Growing: four weeks and 23 litres of water

Planting runs from week 11 to week 42. Iceberg needs four weeks to grow, other varieties six. A single head drinks 23 litres of water, plus 7 g of fertilizer and three hours of irrigation a day.

Czech growers buy their seedlings from the Netherlands and Germany, and planting is staggered across the season so that harvest is continuous rather than one peak.

Harvest and packing

One cooperative in the Polabí region works 4,200 hectares and takes about 2.5 million heads off them in a season — some 5,300 tonnes, of which 70 to 90% is actually harvested.

Packing one head costs CZK 0.50, and washing the crop takes 10 to 15 m³ of water a day. Every retail chain has its own packaging requirements, so the same lettuce leaves the line in several formats.

The 24‑hour window

From the packing line to the shelf, the clock is the binding constraint. Lettuce may spend a maximum of 24 hours in storage at 8 to 14 °C. Past that, the head is no longer sellable as fresh produce.

Ninety percent of the crop goes to supermarkets. Some chains run zero tolerance on quality, so a single damaged head can send the entire batch back.

Why fresh produce tops the waste list

Up to 40% of all food waste is vegetables and bakery goods. The shorter the shelf life, the less room the chain has for error — and lettuce has about as little room as a food product can have.

What to take from it

• Four weeks of growing, 23 litres of water and 7 g of fertilizer go into one head.
• Packing costs CZK 0.50 per head; washing the crop takes 10 to 15 m³ of water a day.
• The storage window is 24 hours at 8 to 14 °C. There is no slack in it.
• Vegetables and bakery are the most discarded food categories, up to 40% of food waste.

Sources and dating

Grower and cooperative data from the Polabí region; food waste figures from Zachraň jídlo.

Originally published as a Czech infographic around 2020. Redrawn in 2026.