Open-pollinated or F1 seeds: can you sow your own seeds again?

On a seed packet, you read "F1", "organic", "heirloom variety" or "open-pollinated". Nobody explains the difference in the garden. Above all, you want to know whether your seeds will give the same plant next year. With a packet marked "F1" or "hybrid", the answer is no. Without those words, it is yes, with a few precautions for species that cross. The guide first presents the three types of variety and how an F1 is made. It then compares them on six criteria, then teaches you to read a packet.

The three types of variety

• Population variety. It is multiplied by free pollination. The plants cross with each other every generation. They are not all identical but share common traits. Its genetic base is wider.
• Fixed line. The breeder chooses plants and self-pollinates them for several generations. The plants look alike. Their seeds give the same variety again.
• F1 hybrid. It is born from the cross of two pure lines, of which it is the first generation. It is very uniform and productive in the first year. Its offspring is uneven and less productive.

"Open-pollinated" covers the first two types. You can sow them again. An F1 cannot be. The word "heirloom" has no legal definition. It says nothing about how the variety reproduces. On a packet, check instead for the absence of "F1" and "hybrid".

How an F1 hybrid is made

The seed company starts from two pure lines. It gets them by self-pollinating plants for several generations. With each generation, these lines lose vigour. George Shull saw this on maize in the early 20th century, at Cold Spring Harbor in the United States. He published his results between 1908 and 1910.

Every year, the seed company crosses these two lines in a controlled way. It puts the pollen of one on the flowers of the other, with no random crossing. The seeds collected from the line that bears the fruit are the F1 seeds. They end up in your packet. Shull found that these hybrids outdid their parents in growth and yield. The mechanisms of this hybrid vigour are still being researched.

Your seeds form the next generation. They do not reproduce this cross. The traits of the two lines are redistributed at random. The plants differ from one another and on average produce less. The seed company keeps its two parent lines and makes the cross again every year. You only get the result. The seed company also finds its commercial interest in it, since the customer buys the seed again every year.

Strengths and limits of an F1

Strengths

An F1 is very uniform and very productive from the first year. At a market gardener's, the fruit is the same size, ripens together and is picked in one pass. The seed company can also combine the qualities of the two parents, including disease resistance. Seed company leaflets show codes for Fusarium wilt, Verticillium wilt or tomato mosaic virus. If your soil hosts one of these diseases, a resistant variety can save your harvest. In a vegetable garden, uniformity often matters less. You pick over the weeks. A spread-out harvest rather suits you.

Limits

Your seeds do not give the same plant again. To get it back, you buy a packet every year. You also lose the diversity within the variety, since all the plants of an F1 are alike. A population keeps a wider genetic base. In general, it adapts better to unusual conditions or an unusual season. Finally, you depend on the seed company. If it drops the variety, it disappears from your garden.

Take an example. You collect seeds from an F1 tomato and from a fixed-variety tomato. The following year, the plants from the F1 differ from one another. The fixed variety gives back the tomato you know.

Open-pollinated does not mean effortless

Self-pollinating species fertilise themselves. Pea, bean, lettuce, lamb's lettuce and tomato are among them. They are the easiest to start with. Still, keep a few metres between two varieties to limit crossing. Cross-pollinating species cross between varieties. These include carrot, celery, chicory, cabbage, turnip, onion, leek, radish, squash and cucumbers. Carrots, onions, leeks and beetroot are biennials. They only make seeds in the second year. For tomato, our guide to saving tomato seeds gives the method and the distances.

European rules

In the European Union, a vegetable variety must be admitted to an official catalogue for its seeds to be sold (directive 2002/55/EC). To get in, it must be distinct, stable and uniform enough. An heirloom variety does not always meet these criteria.

Another directive (2009/145/EC) therefore provides two exemptions. Conservation varieties are traditional varieties threatened by genetic erosion. They are tied to their region of origin and sold in limited quantities. Varieties developed for growing under particular conditions have no value for commercial production. They are sold in small packs. In France, they are sometimes called amateur varieties. The Court of Justice of the European Union confirmed the validity of these texts on 12 July 2012, in the Kokopelli case. An heirloom variety can therefore be listed in the catalogue or sold under one of these exemptions.

In organic production, regulation (EU) 2018/848 has allowed, since 1 January 2022, the sale of "organic heterogeneous material" on simple notification, without catalogue listing. A single regulation on plant reproductive material is due to replace these directives. The Commission proposed it in July 2023. The Council and the Parliament reached a provisional agreement on 15 June 2026. It still has to be formally adopted. Until then, the current directives apply.

How to read a packet

1. The variety name, with or without "F1" or "hybrid". If either of these is there, do not save your seeds to sow them again.
2. The exemption wording. "Conservation variety" or "variety developed for growing under particular conditions" points to one of the two cases above.
3. The organic logo. It shows the way it was produced, not whether it breeds true. An F1 can be organic.
4. The date. The supplier's label carries the year the packet was closed or the year of the last germination test. Leek, onion and parsnip generally only keep one or two years. Tomato and squash last several years, dry and cool. To test an old packet, lay ten seeds on a damp paper towel, a week somewhere warm. Count those that sprout. If all ten sprout, sow normally. From seven to nine, sow more densely. At six or fewer, buy a new packet (University of Illinois rule).
5. The weight or the number of seeds. When shown, it lets you compare two packets at the same price. If you are unsure about the variety, ask the seller whether it is a hybrid.

Our choice

All our seeds are open-pollinated. None is an F1 hybrid. Almost all of them come from Semailles, a Belgian organic seed company in the province of Namur. Semailles produces and sells organic, open-pollinated and often heirloom seeds. We do not produce our seeds ourselves. Our job is to choose the catalogue and write the growing sheet for each variety, to help you succeed with it. La Fève Longue de Belgique, le Poireau des Vennes and l'Oignon rouge de Huy are part of it.

This choice does not serve our turnover. We own it. If you save your seeds well, you no longer need to buy this variety from us again. A variety stays alive as long as gardeners sow it. An F1 is nothing like an enemy. For a specific resistance or a very even harvest, it can be the right choice, from another seed company.

Further reading

• The collection: Vegetable seeds
• The Start page: Tell us which seeds you have, and we tell you when to sow each one where you live
• Three other guides: Saving your own tomato seeds, The Triomphe de Liège tomato and Sowing calendar for Belgium

Photo: Fabian Kleiser, Unsplash