Last week, I spoke with Dianne Ott Whealy, the co-founder of Seed Savers Exchange, to discuss the history of that important organization. SSE is approaching its fiftieth year of operations, so there was much more to the story to be explored. For that, we continued the conversation with this week’s guest – SSE Director of Preservation, Phil Kauth for more of what goes on at Seed Savers Exchange behind the scenes.
Phil has been a part of the Seed Savers Exchange team since 2013, and he brings a strong pedigree of knowledge and experience. With a Ph.D. in horticultural sciences and a background in unique fields like seed biology and aquatic plant research, Phil was just the right guy to bring operations at SSE to the next level.

Phil is just one of around fifty SSE team members – all of whom are passionate about maintaining biodiversity for our future. (photo: Roger Hartwell)
Maintaining Viability
The Seed Savers Exchange team of 50 staff members (along with plenty of seasonal help) are all committed to the mission of preserving open-pollinated heirloom varieties of plants. Over the years, they have accumulated and preserved a collection of over 20,000 open-pollinated varieties.
Every unique variety is carefully stored in one of several storage rooms with conditions designed to prolong the seeds’ viability. Seeds stored in the SSE seed vault can remain viable for up to a century, thanks to a constant 20-30% humidity level at 0 degrees Fahrenheit.
Each variety of seed stored undergoes a germination test every 6-10 years. The results of those tests play a role in determining which crops will be grown on the nearly 900 acres of the SSE Heritage Farms each season. The SSE Seed Bank Manager evaluates germination rates, along with the stored quantity available, to prioritize what will be planted to produce a new seed crop.
The Field Operations Team is in charge of growing the crops and maintaining varietal integrity, along with harvesting and processing the seed crop for distribution and storage. Thanks to all of this hard work, the genetic diversity maintained by the organization remains robust for future generations.
Seed Savers Exchange still receives new seed every year from people all over the continent. Often, the varieties that come in are already part of the SSE collection. If a seed is already being preserved at SSE, the team finds another home for the new donation. If it’s not returned to the donating family, it’s listed in the Exchange (more on that in a minute), so some lucky gardener can put it to good use.

There are over 20,000 varieties in the carefully catalogued and maintained collection at Seed Savers Exchange. (photo: Roger Hartwell)
There’s no guarantee the donated seeds will germinate. So, when SSE receives seeds which aren’t already part of the collection, staff tests their viability; and that seed is often prioritized to be grown that season. The Field Operations Team manages each crop carefully, but sometimes, the donated seed produces limited results.
Once – out of a collection of 2,000 seeds of corn – only three plants actually germinated. The team carefully hand-pollinated the three, collected the seeds and grew those seeds again the following year in hopes that the crop of the second year will grow and produce with the expected characteristics.
Not Everything Old is an Heirloom
Every variety stored at SSE is catalogued in a meticulously-kept database. Phil likes to say that their records document asparagus to zucchini and everything in between. The collection includes more than just seeds too. There are over 300 varieties of grape, 60 types of Jerusalem artichoke, a vast potato collection, dozens of types of celery, and over 300 varieties of garlic just to name a few.
Most of what’s maintained and catalogued by SSE are heirloom varieties. Phil and the SSE team make a unique distinction about what constitutes an heirloom. They consider a plant to be heirloom only when it has a history of being passed down within a family or a community. Some heirloom varieties are only a few decades old, but it’s the stewardship of a community of gardeners that makes it an heirloom.
On the other hand, some of the varieties at Seed Savers Exchange have been available and sold by seed companies for at least a hundred years, but without a history of stewardship, they aren’t considered an heirloom. They refer to these old, non-heirloom varieties as “historic commercial.”
Phil likens the difference to an antique versus any item which has been passed down in a family. You can buy an antique, but something only becomes an heirloom once it has some sort of family history.

Conditions within the SSE seed vault are ideal for maintaining viability. Seeds stored here could remain dormant – but alive – for up to a century. (photo: Roger Hartwell)
A great example of this is a long lost bean variety that SSE recently added to their collection. Last week, Dianne mentioned that the largest collection they received was from John Withee, an amateur collector in New England. Of the 5,000 varieties he donated, there was one which SSE had been unsuccessful in germinating – the Hobbs Goose Bean.
Fortunately, many SSE members are just as passionate about preserving at-risk varieties, and one member, in particular, was on a mission to find viable Hobbs Goose Bean seeds. After years of searching, the member stumbled across a social media post from the Kent State University community in Ohio. A woman there mentioned she was growing Hobbs Goose Bean that season.
It turns out that Dr. Hobbs, who had developed a fondness for this bean variety and traced its origins to the 1800s, had been a professor at Kent State. In the 1970s, he began sharing beans with other gardeners in his area, which generated a community-wide appreciation for Hobbs Goose Bean. Thanks to this network of seed stewards, it’s being grown at Heritage Farms this season, and may soon be making an appearance in their catalogue.
Beyond the Seeds
Not every crop is grown from seed, so its contribution to genetic diversity must be cultivated in other ways. Potatoes are one example. Each variety of potato will set small fruit and seed, but only when pollinated by a different variety of potato. As a result, the seed contains the DNA of both potato varieties. This is known as outcrossing, and it produces heterozygous seed. In other words, the crop grown from that seed will be a wildcard mix of qualities from both parent plants.
This natural cross-pollination isn’t always a bad thing. In fact, it’s how most of what we enjoy in the garden today came to be.

Each variety of seed in the SSE collection is put to a germination test every six to ten years. (photo: Roger Hartwell)
Do you like tomatoes? Well back in the 1800’s, tomatoes weren’t particularly popular. Instead, they were believed by many to be poisonous. In those days, you might can tomatoes, but you wouldn’t want to eat one fresh off the vine or on a sandwich. Then came Andrew W. Livingston.
Mr. Livingston tried crossing several varieties manually but still wasn’t happy with the result. So, he decided to see what nature would provide. He planted all his varieties in close proximity and let the pollinators take charge. As fruit would form, he saved seeds from the stand-outs and, over time, bred the seed from the best fruit into some of the genetically stable, tastier versions which led to many of the varieties we enjoy today.
But let’s get back to those potatoes. Since potato seeds won’t produce true-to-variety plants, asexual or vegetative propagation is necessary. If you’ve heard the term “seed potato”, that’s actually referring to a tuber rather than a seed. The tuber is produced by the parent plant and is, essentially, a clone of the parent.
The Tissue Culture Manager at SSE is responsible for growing the collection’s 750 varieties of potato tubers – seed potatoes – in test tubes in a laboratory environment.
One aspect of that work is virus-eradication. Potatoes can be subject to and carriers of some serious plant diseases – like Late Blight. In the lab, the Tissue Culture Manager can generate a potato tuber that is free of plant viruses, and over 100 of their varieties have now been tested by an independent lab to ensure there are no viruses present.
Preserving Biodiversity World-Wide
Seed Savers Exchange doesn’t just preserve their vast collection onsite. They also coordinate with federal and global seed banks to ensure these organizations maintain a sample of each variety for storage too.
Phil calls the USDA Agricultural Research Service facility in Fort Collins, Colorado the Noah’s Ark of the United States. There, they preserve not just seed but also animal and insect lines and other samples of genetic diversity, like eggs. SSE provides the USDA a box of samples each year as a backup to their own collection.
Most countries maintain a seed bank of some sort to preserve their own crop heritage, but it’s the global seed bank that holds the largest collection – seeds and other plant materials sent from around the world.
Run by the Norwegian government, the Svalbard Global Seed Vault is located in the side of a mountain on an island in the Arctic. Their vault – known to many as the Doomsday Vault – is opened just twice each year, and Seed Savers Exchange coordinates an annual shipment of unique seed varieties to be stored there too.

The diverse collection of potato varieties is grown out in test tubes in the SSE laboratory. (photo: Roger Hartwell)
Time to Experiment
If you’re interested in trying unique heirloom varieties of plants, Seed Savers Exchange offers several ways to do that. You can order from their catalogue, of course, but you can also check out their Exchange.
The Exchange was created in the early years at SSE. It provided a list of varieties to members who wanted to exchange seeds with each other. What began as a list of 26 gardeners, offering about 70 varieties, has now grown to an online tool where approximately 20,000 varieties are currently listed.
Membership is no longer a requirement for participating in the Exchange. It’s now open to the public, bringing together a network of over 400 gardeners and seed stewards.
I don’t know about you, but I love growing something new and making note of the experience in my journal. So, I was excited to learn about SSE’s citizen science program. As a member of this program, you receive a few varieties of seed from the collection to grow in your garden as a trial. You evaluate how each variety performs in your area and share your observations in an online evaluation tool. It’s a big win-win. You get to grow some fun new types of plant, and SSE gets to learn how each variety performs under different growing conditions.

The GGW crew and I visited Heritage Farms a decade ago to film an episode of the show. Be sure to check Links & Resources to watch the episode and take a tour of this vast property.
I hope you’ll listen in as Phil shares more details on the SSE team and the work they do. Scroll to the top of the page and click the Play icon in the green bar under the page title. If you have an opportunity, plan a visit to Heritage Farms in Decora, Iowa. It’s open to the public from March into late fall every year, and there are tours and walking trails to enjoy some of the most diversely-planted 900 acres in the country. They also host an event the 3rd week of July every year with seed swaps, camping in the orchard, workshops, and lots more. It’s definitely worth the trip.
Links & Resources
Episode 046: Organizing Your Gardening Life
Episode 115: Understanding Tomato Diseases and How to Deal With Them
Episode 150: The Story of Seed Savers Exchange: With Co-founder, Diane Ott-Whealy
Seed Savers Exchange Seed Exchange
USDA Agricultural Research Service
joegardener Online Academy Three popular online courses on gardening fundamentals; managing pests, diseases & weeds; and seed starting!
Master Seed Starting – My newest online course teaching you how to master the art of starting your own plants from seed and seeding care! Registration closing soon, so don’t miss out!
Growing a Greener World® Episode 117: Seed Savers Exchange
Corona® Tools – Podcast episode sponsor and Brand Partner of joegardener.com
0 Responses to “151-Seed Savers Exchange: Behind the Scenes”
I’m so impressed with their organizational skills and your guest’s enthusiasm.I looked at their online website but with the chaos going on it didn’t appear they were taking orders. I have some seeds that I need by 4/10 (mainly direct sow types). So I’ll go back in early July and make my fall/winter order.Thanks again! Stay safe!!!
Shalom,
Hey Joe,Not a response to this episode in particular, but a general comment for the show. You have mentioned that using peat moss is low key bad for the world while the use of coir is at least neutral for the environment and does the same job. I’ve been trying to find some for at least a year, and have finally discovered that, in the big box stores, it is sold as coco fiber or coconut fiber. The employees don’t know the term coir, so using this or aknowledging the alternative terminology in future episodes might save others my ongoing existential headache. Peat should be saved for Scotch, not used in the garden.Thanks for the show!