F1 and F2 Hybrid Seeds Explained

What a hybrid seed is

A hybrid seed comes from a deliberate cross between two different parent lines of the same species. Breeders choose those parents for the traits they want in the offspring, then repeat the same cross every season so each batch behaves the same way. The seed that results is the first filial generation, which is where the name F1 comes from.

How the cross is made depends on the crop, and it is rarely as simple as moving pollen from a male flower to a female one. Most of the vegetables sold as F1 hybrids, including capsicum, eggplant, beetroot and the Asian greens, carry perfect flowers with male and female parts in the same bloom, so the breeder has to stop each flower pollinating itself, either by removing the anthers by hand or by using parent lines that are male sterile or self incompatible. Separate male and female flowers occur in most cucurbits, such as cucumber, zucchini, squash, pumpkin and watermelon, and in sweet corn, while spinach and asparagus usually carry their male and female flowers on separate plants.

Hybrid varieties are bred for traits such as improved yield, flavour, early maturity, stress tolerance and disease resistance, although what you actually get still depends on your soil, your watering and the weather.

F1 hybrids

Plants grown from F1 seed are more uniform than either parent. Sow a packet and they usually come up at a similar height, mature within a few days of each other, and carry fruit of a similar size, so the bed is easy to plan, to space and to pick.

That uniformity belongs to the F1 generation only. F1 plants are not genetically stable from one generation to the next, so seed saved from an F1 crop will not repeat the performance of the packet you bought.

F2 seed

F2 seed is the second generation, grown from plants raised from F1 seed. The genes contributed by the two original parents separate out again, so F2 plants vary: some resemble the F1 plants, others take after one grandparent or the other, and height, maturity and fruit size can all differ within a single packet. F2 seed does not come true to type.

There is one F2 line in our range, Asparagus UC 157 F2. Asparagus is a long lived perennial, and a little variation between crowns matters far less in a permanent bed than it would in a row of lettuce, so this generation is sold in its own right. Everything else we list as a hybrid is F1.

What hybrid seed does well

Vigour and earliness

F1 plants are often quick away and can start cropping earlier than their parents, which is useful in a short season or in a small bed that has to turn over.

Disease resistance

Many F1 vegetables carry named resistance to particular diseases, which is worth a great deal where a soil-borne or leaf problem has beaten a crop in that spot before. Resistance is not immunity, though, and it covers only the diseases named on the packet, so crop rotation, airflow and garden hygiene still do most of the work.

Open-pollinated seed and saving your own

Open-pollinated varieties, heirlooms among them, are pollinated by insects, wind or themselves, and they come true from saved seed as long as they have not crossed with a related variety flowering nearby. Our guide to seed types sets open-pollinated, heirloom, hybrid and GM seed side by side.

That is the real trade. An F1 packet buys uniformity and often disease resistance for one season, and you buy it again next season. An open-pollinated packet may give a less even crop, and it gives you seed you can keep. Peas and beans are the easiest place to start, because they pollinate themselves before the flower opens and rarely cross. If seed saving is part of your plan, start in the heirloom and untreated seeds range rather than the hybrids.

Plenty of gardeners run both: a hybrid where an even, reliable crop matters most, open-pollinated varieties where flavour, history or a saved seed tin matters more.

Hybrid vegetable seed at Happy Valley Seeds

We stock F1 hybrid seed for tomato, capsicum, chilli and eggplant, for cucumber, zucchini, squash, pumpkin, watermelon, rockmelon, bitter melon, wax gourd, hairy gourd and other gourds, for broccoli, cabbage, cauliflower, Chinese cabbage, pak choi, choy sum, tatsoi, komatsuna, turnip and radish, and for sweet corn, carrot, beetroot, spinach, onion and spring onion, along with the single F2 asparagus line, and you can see the whole range in hybrid vegetable seeds.

Related growing guides

• Open-Pollinated, Heirloom, Hybrid and GMO Seeds: What the Packet Words Mean
• Forgotten Heritage Vegetables Worth Rediscovering from Seed
• Determinate vs Indeterminate Tomatoes: Which Should You Actually Grow?
• How long do seeds last? Storing seeds and testing if they still grow

Ready to plant? Browse our hybrid vegetable seeds.