Seed and field

Seed potatoes: how seed potatoes for planting are produced, certified and traded

Seed potatoes are tubers grown to be planted, not eaten. Because a potato crop is grown from tubers, seed potatoes for planting carry the health of the next crop with them, so they are multiplied from disease-tested starting material over a limited number of field generations and inspected at each step. Certified seed is the class sold to growers. This page explains the classes, the main exporters and what to check before planting.

Last updated: 13 November 2026

What are seed potatoes?

Potatoes are grown from tubers, not from true seed, so every crop starts from potatoes saved from an earlier crop. Diseases that live in the tuber, above all viruses and blackleg, travel with it into the next field. Seed potatoes are tubers grown for planting under rules meant to stop that: clean starting material, a limited number of field generations, and official inspection of the growing crop and of the harvested lot.

The full system, country by country, is in the seed potato systems guide. How certification works as a process is answered in seed potato certification.

How seed potatoes for planting are multiplied

Seed multiplication starts in the laboratory and glasshouse. In Western Australia's certified scheme, generation zero (G0) is minitubers, microtubers or plantlets from accredited labs and glasshouses; seed may then be multiplied for at most five field generations, and any generation may be sold as certified seed if it meets the standard (DPIRD Western Australia, Certified Seed Potato Scheme rules, Aug 2023).

Uganda's 2022 protocol follows the same pattern, from tissue-culture plantlets, mother plants, rooted cuttings and screen-house minitubers to field-certified seed tubers (Ministry of Agriculture, Animal Industry and Fisheries, Seed Potato Inspection and Certification Protocol, May 2022).

In the European Union the field generations carry legal grade names. Basic seed is graded S, SE or E, and certified seed is graded A or B; each grade has a ceiling on off-types, blackleg and virus symptoms (Commission Implementing Directive 2014/20/EU).

EU grade	Type	Blackleg in crop	Virus in direct progeny	Max. field generations
S	Basic	0.1%	1.0%	5
SE	Basic	0.5%	2.0%	6
E	Basic	1.0%	4.0%	7
A	Certified	2.0%	8.0%	Not set
B	Certified	4.0%	10.0%	Not set

Maximum shares allowed. Source: Commission Implementing Directive 2014/20/EU, Annexes I and II (EUR-Lex). Pre-basic classes are not defined in this act.

Where seed potatoes come from: the biggest exporters

Seed potatoes are traded under HS code 0701.10. The Netherlands is far ahead of every other exporter: 922,273 tonnes worth US$802.4 million in 2025, more by value than the next six countries together (World Bank WITS / UN Comtrade, 2025).

Exporter, 2025	Value (US$ million)	Quantity (tonnes)
Netherlands	802.4	922,273
France	173.4	275,531
Germany	95.7	120,842
United Kingdom	88.5	Not published
Belgium	61.1	85,103
Denmark	56.0	69,638
Canada	33.8	69,526
Egypt	26.3	29,573
United States	19.5	22,372

Exports of HS 070110 to the world, as reported by each country. Source: World Bank WITS / UN Comtrade, 2025.

Planting seed potatoes: what growers check

Buy certified seed and order it by variety, class or generation, and size (Potatopedia growing guide).
Do not plant shop potatoes: they can carry viruses such as PVY and PLRV without visible symptoms (Potatopedia growing guide).
Pre-sprout (chit) seed for 2 to 4 weeks at 8 to 12 °C in diffuse light before planting (Potatopedia growing guide).
Plant when the soil is above 10 °C at 10 cm; seed pieces rot below 7 to 8 °C and emerge unevenly (Potatopedia growing guide).
Typical spacing: 25 to 30 cm in the row, 8 to 12 cm deep, rows 75 to 90 cm apart (Potatopedia growing guide).

More in the complete growing guide and common growing mistakes.