Its Heritage Seed Library houses around 800 varieties at any one time. None of the seeds are commercially listed so they can’t legally go on sale, although members can get hold of a selection each year to try on their own plots.

Heritage and heirloom seeds are open pollinated, which means the seeds are formed naturally, better adapted to their local environment and can be saved and resown each year. The saved seeds of the most delicious, nutritious varieties have been handed down on smallholdings for generations, and now these seeds are enjoying a revival thanks to growers who are passionate about their potential for improving the variety of food we eat, the tastiness of our dinners and even global food security.

Catrina Fenton, head of the Heritage Seed Library, explains: “From our perspective the seeds are a very important genetic resource that could be lost. They are a cultivated biodiversity. It’s important that we have sufficient choices as gardeners when it comes to climate change, pests and diseases and through them we can find varieties that can adapt to environmental stress we don’t know about yet. They are important tools in our bag, part of the future, not the past.”

“We use the term ‘heritage’ quite loosely, it catches many things,” Catrina says. Heritage seeds include heirloom seeds, which are often named for a person or place. These may be unique seeds bred by an individual or may simply be a colloquial descriptor for an already named variety detached from its identifier. “You could have a name like ‘Uncle Fred’s peas’, for example. Uncle Fred may have bred them himself or they might have been varieties that were once available from a seed merchant, then stopped being available to buy and so the seed was saved,” she observes. For example, Silsden, near Keighley in Yorkshire, may claim the cabbage ‘Silsden Bomb’: it is believed to have been bred by Jonnie Watson, a veteran gardener there.

True historic varieties tend to be older than heirloom seeds and will have historic records attached to them. The oldest variety in the Library’s collection is the broad bean ‘Martock’, with descriptions of this variety dating back to 1294. “There are lovely stories around the history of these seeds,” Catrina observes. “In this case, the vicar of Martock would give the seeds to his parishioners.”

Far from wanting to keep seed locked away, saving a seed from risk is, Catrina says, her “ultimate aim”. In practice this means the seed becoming listed for sale commercially. One success story is ‘Bronze Arrow’ lettuce, which is now widely available as ‘Bronze Beauty’ and so will be taken off the register to make room for another seed.

“It’s a fantastic lettuce,” Catrina says. “It’s cold hardy, drought hardy and very prolific. Once our seed stocks have been shared with our members it will come out of the national collection because it’s not one that we need to look after any more.”

The UK’s and the Heritage Seed Library’s first-ever seed relay will start on 13 October 2025 to celebrate the Library’s 50th birthday, and highlight the importance of the seeds it preserves.

The relay will have three parts. The first, starting in Bocking in Essex (the original home of the Heritage Seed Library and Garden Organic) will cover 180 miles to finish at the Library’s current home, Ryton Gardens near Coventry. On the way, a special package of seeds will travel through London, Buckinghamshire, Oxfordshire, Northamptonshire, Rugby and Warwickshire, and at each stop, ‘seed champions’ will take a packet to grow – and eventually harvest and save – before passing the rest of the seeds onto the next destination. The second and third parts take place in Scotland and Wales in 2026.

Fiona Taylor, CEO of Garden Organic said: “The Heritage Seed Library conserves seed by sharing it. Passing seed on to be grown by friends, neighbours and future generations is a simple action that gardeners and growers can take to ensure our food crops adapt to climate change.

“Seed is a precious natural resource, and open pollinated seed continually adapts to the conditions in which it is sown. This means by passing seed on and sowing it in a variety of places, we are allowing it to survive and thrive.”

Pea ‘Robinson’ Extraordinarily sweet, retaining their flavour even when frozen.

Lettuce ‘Bronze Beauty’ A really beautiful lettuce that’s cold tolerant and drought tolerant (previously known as ‘Bronze Arrow’).

Spinach ‘King of Denmark’ Delicious in salads when young. When mature, and slightly crumpled, they’re equally tasty.

Bean ‘Greasy’ At its best used as a dried bean to best enjoy its rich, smoky, peanut-like flavour.

Tomato ‘Manx Marvel’ Thought to have been bred on the Isle of Man, these vigorous tomatoes have strong stems that can withstand wind.

To maintain the viability and volume of its seed collection, the Heritage Seed Library must grow the plants in its collection regularly. Without the space or means to grow what is necessary themselves, staff depend on an army of volunteers around the country to grow what are known as ‘Orphans’ – varieties that are low in stock.

Roughly half of the 40,000 packets of seed distributed to members have been grown by volunteers. “We really are dependent on these volunteer growers,” says Catrina. “They’re a lovely group of people from all walks of life. They are always enthusiastic and we have a nice communication with them.”

To become a Seed Guardian, volunteers must have paid their £18 annual membership of the Library and they should be experienced growers. Early in the year an Orphans List is sent out to volunteers, and new growers will be able to indicate a preference for one or two varieties to cultivate. Sometimes these varieties are still being trialled, so they may not yet be widely available.

“We send out seed, and at the end of the year they harvest the new seed and send it back in a parcel,” explains Catrina. Returned seed is then processed by Library staff and made available to members.

See gardenorganic.org.uk/hsl