How this organic farm preserves over 200 heirloom seed varieties every year

Foodthink’s Perspective

As the commercial seed industry continues to grow, heirloom seeds and ancestral varieties are becoming increasingly marginalised. Their disappearance is not only a loss of biodiversity but also signals the gradual decay of diverse local culinary traditions and cultures. However, a growing number of seed savers are now recognising the vital importance of these heirloom varieties. Guided by scientific methods, their goal is not only to collect and preserve these seeds but also to expand their cultivation and revitalise them.

At the end of 2022, during the “Rebirth of Seeds: A Collision of Farmers and Foodies” sharing session at the Beijing Harvest Festival, Tang Yaozhong (known as “Brother Tang”), Technical Director of Yuefengdao Organic Farm, shared the farm’s experience in preserving heirloom seeds. For several years, Yuefengdao Farm has been “sowing a hundred grains and storing seeds in the soil”, and has now protected over 200 local varieties.

This article will address the following questions:

How is the work of seed preservation carried out?
In an era of frequent extreme weather, what challenges are encountered during the preservation process, and what unexpected discoveries have been made?
Is it truly worthwhile for a farm to save seeds year after year? How can heirloom varieties move from preservation to expanded production, and how can seed-saving efforts achieve more sustainable value?

This article has been compiled and expanded based on Brother Tang’s presentation; click here to watch the full replay of the session. Foodthink has also long been focused on seed-related issues. Since 2021, in collaboration with the Farmers’ Seed Network, we have funded 12 partners across the country to establish their own community seed banks.

I. Why we must preserve heirloom seeds

My name is Tang Yaozhong. I manage the on-the-ground production at Kunshan’s Yuefengdao Organic Farm, and many people know me as ‘Brother Tang’.

● Brother Tang and an auntie harvesting saved bean seeds in the field.

People often ask us: why put so much effort into saving our own seeds and conserving these heirloom varieties?

Setting aside the broader issue of biodiversity, from a purely practical standpoint, as an organic farm, we have our own seed requirements.

It is currently very difficult to source organic seeds on the market; and when they are available, they are often expensive. Furthermore, issues with purity, quality, or a lack of adaptability to the local environment mean that some seeds cannot reliably meet our production needs. For instance, we once bought spinach and amaranth seeds that failed to germinate twice; it was only on the third attempt that they finally sprouted and grew. Such unpredictability impacts procurement costs, labour hours, and our sowing schedules.

Yuefengdao Farm has saved its own seeds since its founding in 2010. Initially, however, we focused on varieties that were well-accepted locally, easy to grow, and simple to save. Back then, our methods were somewhat rudimentary, and the quality of the saved seeds was inconsistent.

In 2017, with the support of the ‘Farmers’ Seed Network’, we began to intentionally structure our seed saving and conservation efforts, establishing a modest seed bank. By 2020, as the variety of seeds we collected grew, we began to systematise the entire lifecycle of our in-situ seed bank—from conservation and saving to the ‘activation’ and reuse of the seeds.

Kunshan is economically developed, and as industrialisation has expanded, arable land has shrunk, making heirloom seeds—particularly ancient varieties—increasingly difficult to find. As guardians of these seeds, our process of searching for and preserving them also involves uncovering and documenting the culinary customs and human stories behind these old crop varieties. Through the farm’s nature education programmes, we weave these elements together, enabling visiting city-dwellers to experience and understand local traditional agricultural culture and history firsthand through the seeds.

Only by understanding the source of our food can we find the motivation to preserve its legacy.

II. How over 200 heirloom varieties are preserved

Yuefengdao Organic Farm is located between two water sources, Yangcheng Lake and Kuilei Lake. It was established with the primary aim of protecting these water sources from pollution caused by chemical inputs. The farm covers approximately 230 mu, and including the organic rice grown in partnership with the local community, the total managed area is nearly 600 mu. Since 2020, the farm has set aside two dedicated areas for the conservation of heirloom seeds: an aquatic crop base and a dryland crop base.

● Blue areas indicate dry-land crop experimental plots; red areas indicate aquatic crop experimental plots.

The first step in seed conservation is collection. In addition to the seeds we save from our own crops, we also source them from the surrounding community—through our farm workers, local villagers, nearby farms, and exchanges with fellow farmers. Some are collected with the help of seed stations from the local Bureau of Agriculture and Rural Affairs, while others are transferred from the seed bank of the Provincial Academy of Agricultural Sciences.

Next, based on the specific characteristics of each crop, we allocate plots and draw up planting plans, categorising the varieties for the year: which require direct sowing, which need to be raised in nurseries, and which require pre-cooling to stimulate germination. Before sowing, the seeds are selected and air-dried. This ensures higher quality seeds and a superior germination rate.

● Left: Farm interns Zhang Qian and Chen Zhao sorting through cruciferous seeds to remove impurities. Right: Rice seedlings being raised in a paddy nursery.

After sowing, the primary focus shifts to comparative trials and meticulous tracking and observation, monitoring changes in crop traits at key growth stages.

● Field observations during the rice production cycle.

Once the seeds mature, they are harvested, recorded, sorted, and placed in the seed bank. Upon entry, we take photographs and record measurements and weights to maintain a detailed archive of each variety.

● Once the rice matures, the panicles are cut, the seeds selected and air-dried, and then stored. Seed conservation is a painstaking process; interns Zhang Qian and Chen Zhao, who joined us through the Foodthink “Ecological Agriculture Internship Programme”, have provided invaluable support with this detailed work. From left to right: A Tang Ge, Zhang Qian, and Chen Zhao.

Some of the stored seeds are placed in seed preservation boxes, while others are featured on the “Multi-functional Seed Display Wall” for public science education and outreach.

● The farm’s two specialised seed preservation boxes: one serves as the primary seed bank and the other as a backup, providing double security. These boxes maintain a low-temperature, constant-humidity environment to ensure the quality and germination rate of the seeds.

● The “Multi-functional Seed Display Wall” also serves as an educational hub for the farm. Why “multi-functional”? Because in addition to showcasing seeds, it features crop specimens, such as whole rice plants and ears of wheat. This visual detail, combined with visits to the seed fields and expert guidance, allows the public to embark on an immersive journey into the “past and present” of the seed.

By 2022, more than two hundred heirloom varieties had found a home at the farm. In the wetland crops area, we have conserved 101 varieties of rice and one variety of water bamboo, while the dryland crops area hosts 113 crop varieties, including wheat, beans, and various vegetables.

III. Dryland Area: Legumes, Wheat, and Vegetables

In 2022, we planted 113 heirloom crop varieties in the dryland area, including 33 varieties of legumes, 22 varieties of wheat, and a total of 61 varieties of other vegetables from the Apiaceae, Brassicaceae, Cucurbitaceae, and Solanaceae families. Planting such a vast array of varieties on a single plot of land was quite a challenge for me.

● Dryland crop area: watering the beans after sowing.

From 2021, Yuefengdao Farm began experimenting with the systematic preservation of bean seeds. Initially, we trialled many varieties, including six that the farm had always saved and others collected from various locations. However, only a few truly adapted to the local environment and were successfully preserved.

In 2022, we organised the beans saved from the previous year according to their colour, characteristics, and intended use, adding protective buffer rows around them to reduce external interference.

● Seed saving plan for selected bean varieties.

Following local farming traditions in Kunshan, beans are sown every May.

While sorting through the farm’s saved broad bean seeds before planting, we noticed they seemed to belong to two different varieties. In terms of colour, one was a pale greenish-white, and the other a greenish-brown. Some of the darker beans also featured a white line on the hilum (the ‘navel’).

Beyond their appearance, each variety offered a distinct taste and texture: the white ones were creamier and cooked more quickly, while the smaller green variety, though less starchy, possessed a more intense aroma and a richer flavour.

● A comparison of broad bean seeds saved by the farm.

Among the local bean varieties we have preserved, the most distinctive is undoubtedly the ‘Niu Ta Bian’. Traditionally grown in the Suzhou and Shanghai regions, these beans are long, round, and flat—their shape resembling an ox’s hoof. They are prized for their fragrant, soft, creamy, and sweet flavour. The Qing Dynasty poet Qin Rongguang wrote in his “Bamboo Branch Lyrics”: “Purple fragrance and green jade, the beans have many a name; black shells and green skins fill the jars. June Yellow and Niu Ta Bian, their tender pods cooked as a vegetable dish.” This shows that these beans are not only delicious and nutritious, but also carry a rich cultural history.

● Last year, the farm harvested 80kg of Xiangjing edamame. We commissioned Xiucai Bean Workshop to produce a small batch of dried tofu in two different flavours, which received positive feedback from consumers.

Wheat cultivation was once a tradition in the areas surrounding Suzhou, but it has become increasingly rare. In 2021, we finally managed to collect some local heirloom wheat seeds; however, when they arrived, there were only about 20 grains per variety. With so few seeds, every single one was precious. I remember one variety, called ‘Zhang Si Huang’, of which only a single plant eventually survived. Thankfully, this resilient plant did its part and produced enough seeds for us to continue cultivation this year.

● Through our collaboration with the Farmers’ Seed Network, we have adjusted our planting plans. Out of 22 varieties, 21 are now planted individually within a small plot; two varieties have been selected for cultivation in ‘lineage plots’, and another 18 are grown in ‘ear-row plots’. We hope this will help to purify and revitalise the seeds.

In 2022, we also expanded our seed-saving efforts to include a wider variety of vegetable crops, such as tomatoes, muskmelons, radishes, maize, pak choi and Chinese cabbage.

● Tomatoes and carrots seed-saved at the farm; their unique shapes and flavours are recorded after harvest.

● The local specialty ‘Yellow Wolf Pumpkin’. Remarkably, the same variety can produce a wide array of shapes—some elongated, some round, each one unique. When we replant next year, we aim to achieve more consistent traits through selection and stabilisation.

● Cross-pollinating cruciferous vegetables (such as pak choi and Chinese cabbage) are prone to cross-breeding and mutation. In 2022, we specifically selected five varieties of leafy greens and planted them in separate areas of the farm, using spatial isolation to improve the purity of the saved seeds.

When it comes to seed saving in dryland farming, the greatest challenge lies in mastering the timing of each crop’s growth stages. The table below provides the observation records for soybeans, detailing characteristics such as the germination period, emergence rate, leaf shape and colour, flower size and colour, and pod shape and colour.

These growth milestones were established through collaborative observation and research with our interns. Given our limited experience, the developmental stages for each crop may not be entirely precise. However, they provide us with a clear starting point and a timeline, making it much easier to track and record progress in the future.

IV. Aquatic Plots: A Kaleidoscope of Rice

For many, the first impression of rice is simply “white rice”—lush green in its youth and golden when ripe, with every variety looking more or less the same. However, a visit to our aquatic crop site offers a different perspective. Rows of diverse rice varieties reveal a kaleidoscope of colours—greens, reds, purples, and blacks—each with its own distinct texture and characteristics. In fact, statistics show that there are as many as 140,000 species within the Oryza genus worldwide.

● The aquatic crop site: the areas marked with white signs are the 101 rice seed-saving plots, with each sign representing a different variety.

In 2022, based on preliminary data analysis and cultivation planning, we trial-planted 101 rice varieties.

In recent years, the farm has been frequently hit by periods of high temperature and humidity due to extreme weather. Coupled with frequent typhoons and heavy rainfall, the risk of lodging is particularly high if the rice plants grow too tall. In 2021, two rice varieties failed to be harvested, highlighting the significant difficulty of successful seed preservation.

Consequently, in 2022, we established selection and breeding standards for our rice. We chose to scale up a few varieties with superior traits, while other varieties were kept on a small scale for seed saving. We selected 17 existing varieties and added 10 new ones, making a total of 27 rice types for expanded cultivation. We intend to monitor these closely to determine if they are suitable for large-scale field production in the future.

● Rice selection and breeding standards for 2022.

● Tom and the interns inspecting the expanded rice seeds.

In fact, heirloom varieties such as ‘Su Yu Nuo’ and ‘Ya Xue Nuo’ have already moved into large-scale production, and the farm is already selling related products. This year, we conducted three sets of intercropping trials with these field varieties, each with a specific goal: pairing small black rice with Nanjing 46, and ‘Ya Xue Nuo’ with ‘Su Yu Nuo’, was intended to prevent lodging; whereas intercropping white glutinous rice with Xiang Xue Nuo was aimed at combating sheath blight.

● Rice trait recording sheet, including tillering characteristics, plant height, panicle shape, heading date, and final yield, to serve as a reference for next year’s planting and to ensure traceability for seed preservation.

As the saying goes, “the land shapes the people”. Those of us raised in this land of fish and rice have a responsibility to protect our local rice varieties. By preserving more seeds, we secure both food security and a wider diversity of flavours.

V. Hardships and Challenges

Seed preservation is rarely smooth sailing. Of the 113 varieties in the dryland plots, only 88 were successfully preserved, with 25 failing to yield a harvest. Upon analysis, we found that the vast majority of these failures were due to poor seed quality. Some seeds were a year old, or even two or three; others were foreign varieties, particularly those from the north, which struggled to adapt to the local climate. Even when these seeds germinated, they became highly susceptible to disease later on. Due to the high rainfall, some bean varieties—which are not moisture-tolerant—moulded before the pods could ripen.

In response to these issues, we plan to adjust our legume cultivation: staggering the sowing dates to avoid extreme weather; widening the plant spacing to improve ventilation and reduce disease; and experimenting with reduced fertilisation to see if we can improve the pod-setting rate.

The farm successfully harvested all 101 rice varieties planted in 2022, but this presented a new challenge. With over 100 varieties already and the potential for more, the workload becomes overwhelming if every single variety must be replanted annually to ensure meticulous purification, rejuvenation, and record-keeping.

We considered whether we could rotate the varieties, planting them in batches over two or three years. However, we first need to audit the seed stock and test germination rates. To rush into batch planting without this would risk some seeds failing to sprout, meaning the legacy of these heirloom varieties would end with us.

● Following the January harvest, we collaborated with the local agricultural extension centre to host a tasting event for superior rice varieties. We invited 40 fellow farmers, consumers, and partners to conduct blind tastings and score the new crop. By assessing appearance, texture, and colour across a range of offerings—including new and heirloom japonica rice, glutinous rice (including coloured varieties), fermented rice (laozao), and rice cakes—we aimed to identify the ‘star rice’ of each category.

This year, we plan to further refine our selection of rice varieties for 2022, reducing the number of varieties for propagation to 19. From these, we will select two for large-scale production to bring them to the consumer’s table. We will also choose three bean varieties to expand their cultivation area and develop a range of bean-based products. After all, it is only by creating viable products and gaining consumer acceptance that we can ensure the long-term sustainability of heirloom seed conservation.

Photos provided by Shen Ye, Kunshan Yuefengdao Organic Farm, and the Farmers’ Seed Network

Compiled and written by Shen Ye

Edited by Wang Hao