This year's Heritage Seed Library seed trials

The Heritage Seed Library is a living and dynamic collection, and we actively find, assess and conserve rediscovered heritage varieties. Each year we typically reintroduce five to 10 heritage varieties, conducting growing trials and evaluating before adding to the collection, ensuring they're securely conserved for future generations.

Each variety is checked for germination, vigour and susceptibility to pests and disease.  They are measured and recorded to ensure a strong, successful variety, unique to the collection and consistent across the plants grown.  All the information collected is then reviewed at the end of the season and successful varieties are officially added to the HSL permanent collection where they will be conserved and, in the future, made available to HSL members.   

Each conserved variety helps to counter the continuing decline in biodiversity. Importantly, open pollinated or naturally regenerated varieties are genetically variable, just like individuals in a population rather than clone copies. This means they have the potential genes to adapt to the growing challenges of the future, such as increased droughts, flooding and extreme temperatures. Getting people growing and enjoying heritage varieties is an important way to reduce genetic erosion and build the resilience that open pollinated varieties offer in back gardens around the country.

The varieties, which have already had full background checks, are grown and trialled on site at our site in Ryton Organic Gardens, Coventry. From sowing the first lettuce in January to picking the last pod from the radish in October the varieties are tended, inspected, accessed and characterised by the horticultural team at HSL. 

Thanks to the Sowing Your Seeds project, funded by the National Lottery Heritage fund, 2026 is going to be a bumper year for trials with 27 new varieties reaching the sowing phase. These include:

Amaranth - 'Charlie’s Callaloo'

A treasured pack of callaloo seed was brought to the UK in the 1950s by our donor, Charlie, who was part of the Windrush Generation. A much-loved staple, this callaloo was grown and seed saved on his allotment over the years until his passing in 2019. It was identified as needing conserving by the organisers of the Bedworth Seed Swap, and a pack of these precious seeds was collected from Charlie’s family and kindly shared with the HSL for trialling.

Amaranth - 'Scunthorpe Denga'

This seed was given to our donor 10 years ago by a Bangladeshi friend who grew and seed saved it in Scunthorpe. Our donor started to grow and cook with it for her late Bangladeshi husband, and it’s been on her allotment in Shropshire ever since! Said to be beautiful and prolific self-seeder, we’re really looking forward to giving this a try.

Carrot - 'Suttons Favourite'

An ex-commercial variety originally, as the name implies, from Suttons Seed Merchants. Its 1933 catalogue includes it in the maincrop carrot section. It's described as "strongly recommended for general use in private gardens. Best described as a stump-rooted form of our 'Scarlet Intermediate'.” It made it across the Atlantic too - and in an advert in the Newfoundland Daily News (29 May, 1950) for McMurdo’s Garden Supplies, it's highlighted as a ‘new arrival’.

Celeriac - 'Seldra'

Released as a cultivar in 1982 in Denmark by A Hansens. A uniform celeriac with a large tuber, medium to late developing with a light brown outer colour and somewhat wrinkled. The yield is said to be high when harvested in the autumn and it has good shelf-life when kept in the fridge. It's also said to be prone to bolting.

Parsley - 'Bravour'

A brand-new vegetable for the HSL - we’re really excited to trial this parsley! Awarded the RHS Award of Garden Merit in 1997, it was described it as "an attractive curled variety that grows to around 30cm but with a compact habit. The masses of tightly curled, dark green leaves have a great flavour and it could also be planted as an ornamental or in containers".

Quinoa - 'Yolande's Quinoa'

Grown on Yolande and Andrew’s vegan smallholding in Herefordshire for the last 10 years as part of their move towards self-sufficiency. This will be the first quinoa trialled by the HSL, so we’re really looking forward to learning more about this protein-rich vegetable.

Runner Bean - 'Bumpsteed Black'

This bean is being given a second chance after a (partly) successful trial in 2025. Originally a ‘sport’ of a commercial variety that produced black seeds. This characteristic was nurtured and propagated by our donor for more than 20 years. Producing a vigorous plant, this unusual variety grew brilliantly at HSL but a few plants still produced the traditional purple and black speckled seed. The seeds produced, both all-black and speckled, could not be kept since they had been cross-pollinated between each other, so the clever horticultural team had to come up with another idea. Vines from the all-black seeded plants were painstakingly traced back to the roots (picture the tangle of vines on your A-frame and multiply by 100!) and the roots, rather than the seeds, have been protected for re-growing next year with hopes of a successful all-black crop this year.

Runner Bean - 'Handsome Jonny'

Originally from Poland, this white seeded runner bean was grown by our donor on Pheasey Allotments in Birmingham. It produces really large beans, often used as an alternative to butter beans.  

Tomato - 'Miranda'

Our donor originally bought these seeds in an open-air market when holidaying in Albir, Spain. They were named Miranda and cultivated in Hampshire, for many years before our donor’s move to Oswestry in 2019. They have been cultivated and seed saved there every year since. A rich, sweet and very fleshy orange tomato, with not too many seeds and generally the size of a fist.

Tomato - 'Orange Hat'

Growing to only 20cm tall, this ex-commercial variety is said to be great for indoor growing or interplanting. It can produce a surprising number of small, delicious bright orange fruits.  

Once secured in the library, these will be maintained as a living collection, supported by our Seed Guardians, and eventually shared with our members when we have sufficient seed. Each conserved variety helps counter the continuing decline in biodiversity and builds resilience in our food system as an open-pollinated seed.

Have you been saving seed any heritage or unusual veg varieties?  If so, we’d love to hear from you. Please share more details about your variety here and maybe we could be trialling it next year! 

If you're interested in supporting our trials – join us. Your membership will help support the important conservation work we do. You can also help by making a donation here to assist us with the cover costs of materials such as compost or if you would like to sponsor an entire trial, then please get in touch with our fundraising team via email.