• Seed & Nursery Trade Census


This site hosts research detailing the commercial nursery trade in the United States, from data collected by Seed Savers Exchange (SSE) in 2015. The Nursery Trade Census, previously known as the Fruit, Berry, and Nut Inventory, was initiated by Kent Whealy to document industry trends and aid professionals and hobbyists alike in finding and preserving rare varieties. Prior inventories were published in 1988, 1992, 2000, and 2009.

This site also hosts Seed Trade Census research detailing the commercial seed trade in the United States, from data collected in 2015 as well. Originally titled the Garden Seed Inventory, prior inventories were published in 1984, 1987, 1991, 1994, 1998, and 2004. Several staff contributed to those prior editions, most prominently Joanne Thuente and Kent Whealy.

Several Seed Savers Exchange staff were involved in data collection, analysis, and technical aspects of the 2015 projects, including Dan Bussey, Otter Dreaming, Tor Janson, Katherine Johnson, Tim Johnson, Paul Kadlec, Philip Kauth, Steffen Mirsky, Bill Musser, Grant Olson, Sara Straate, Molly Thompson, John Torgrimson, Pat Torgrimson, and Gabrielle White.

Nursery Trade Census

Directory of Commercial Fruits, Berries, and Nuts in the United States 2015

Data Collection
The scope of this census is the ‘ “mail order” nurseries of the United States. This term may sound almost quaint in the digital age, but remains an accurate description for how consumers receive their orders, if perhaps not how they place them. Retailers who primarily convey plant material to consumers via a physical storefront are not included in this census. Thus it does not include myriad local and regional garden/landscaping stores, nor the national “big box”chains.

Early in 2015,Seed Savers Exchange staff began with the list of nurseries from the 2009 inventory, and then made several efforts to identify other mail order nurseries. These sleuthing efforts included word of mouth recommendations, nursery association list searches, and Internet searches. We contacted each nursery and requested that they send us a spreadsheet of their 2015 offerings plus descriptions. If nurseries did not respond or supply a spreadsheet, their listings were manually harvested from their websites, or if necessary, their hard-copy catalogs if readily available. When nurseries did not provide a spreadsheet and SSE staff had to manually tabulate the listings, staff did not record the nursery‘s varietal descriptions, but rather, the variety name only.

Varietal Descriptions
The varietal descriptions are pulled from various sources, in the following priority order: 1) a detailed description supplied by a vendor source to Seed Savers Exchange during data collection; 2) varietal descriptions from the 2009 census; or 3) a short description by SSE staff or a blank entry for varieties with nothing available from sources 1 or 2 above.

Corrections and Synonymy
After staff compiled and reviewed the listings, they attempted to consolidate the data by merging obvious misspellings and name variations (for example, reconciling ‘Limbertwig, Black‘ and ‘Black Limbertwig‘ listings). Apple historian Dan Bussey used his expertise to reconcile confirmed synonyms (for example, ‘American Pippin‘ = ‘Grindstone‘). In other crop types, little to no effort was made to reconcile synonyms with disparate names.

The issue of synonymy complicates efforts to precisely track biodiversity trends in the United States‘ horticultural trades. There is no legal requirement for accurate seed and plant labeling in the U.S. In other words, if a retailer receives ‘Butte‘ almond and decides to market it as ‘World‘s Best,‘ there is no law against it (unless ‘Butte‘ is a patented variety). This stands in contrast to requirements in the European Union, where every variety has to be registered and can only be marketed by its registered name. Due to this long-standing United States tradition, synonymous names are profligate and difficult to accurately reconcile. There are also some word-of-mouth opinions about synonymy that are unproven or incorrect, though commonly repeated. And finally, without visual inspection and/or genetic testing of every variety in the census, there is still, through no fault of the vendors, some degree of uncertainty that the variety name on every plant tag is accurate. We have therefore taken a conservative approach and not combined potential synonyms for most crop types.

This is a departure from our past philosophy, mostly due to our own experience addressing these issues in our plant collection. In prior inventories of the nursery and garden seed trade, Seed Savers Exchange took an aggressive approach to merging reputed synonyms. In 2011, we hired a full-time seed historian and began to delve deeply into the stories and histories behind the varieties in our own gene bank. We have been able to confirm some specific cases of synonymy, and we have proven others false. But on balance, it is a work in progress. Beyond apples, we feel we do not have the staff expertise needed to address this issue effectively. Nor is it so simple a task that our judgements will lead to less confusion and a more accurate understanding of every listing‘s true identity. We felt it was better not to merge potential, but unverified, synonyms, rather than accepting as true various synonymy claims. In this respect, the 2015 census departs in methodology from prior editions.

New Crop Types
In another change for this census, staff pulled several “new” crop types out from our very large “miscellaneous” sections. Generally speaking, if a crop type had at least 10 different varieties, and/or had a clear identity, we created a new crop type. This was done in large part to aid usability of the census. The 2015 nursery census contains 53 “new” crop types. We also made a few changes to existing crop types to improve botanical accuracy, most prominently, changing the ‘Tangerine‘ crop type to its proper name, ‘Mandarin,‘ and creating three subclasses therein: ‘Clementine,‘ ‘Satsuma,‘ and ‘Tangerine‘ and  All Other.

Defining a ‘Unique‘ Variety
Some crop types are propagated clonally, in which case “new” varieties can be generated in multiple ways. The method most familiar to people is sexual reproduction, where the offspring is a cross of different two varieties or a genetic “reshuffling” created by self-pollination. There is also a long tradition of people noting and selecting “ ‘sports” from clonal varieties. Even clonal varieties have a low rate of background mutation, which means that occasionally an individual will arise that is mostly, but not exactly, the same as its clonal parent. These “selections” are difficult to classify. Are they new, unique varieties, or just variations of the old variety? In practice, the nursery trade plays it both ways. For example, ‘Hoople‘s Antique Gold‘ apple is a selection from ‘Golden Delicious‘, but usually marketed as a unique variety without notation of its parentage. In contrast,  Plant Foundation Services of UC Davis retains the parent identity of its grape selections, but gives each selection a unique identifying number. For example, it offered 69 different numbered selections of ‘Cabernet Sauvignon‘ in 2015.

As in previous census editions, SSE counted and listed these selections as “unique” varieties. This decision has a large effect on the varietal counts for some crop types and vendors, most prominently grapes and the listings of Plant Foundation Services.

Within the apple listings, historian Dan Bussey made every effort to group clonal “selections”together for the convenience and edification of those utilizing this census. For example, ‘Hoople‘s Antique Gold‘ is listed as ‘Golden Delicious, Hoople‘s Antique Gold.‘ Similar grouping efforts were not made with other crop types in this publication.

Defining Edibility
What defines an “edible plan” is ultimately subjective. In the 2015 census, SSE staff recorded approximately the same crop types censused in previous editions. Large increases in the numbers of documented varieties in “borderline” edible crop types suggest to us that staff used a more liberal interpretation of “edible” in the 2015 edition than in prior editions. For example, the number of Dogwood varieties went from four to 35. This variance in definition probably only influenced a few crop types, but may have inflated the total 2015 census tally of unique varieties documented. The prior editions [1988, 1992, 2000, 2009] were all compiled and/or edited by Joanne Thuente, who retired in 2014. These editions probably had more continuity in definition of edibility compared to the 2015 census.

Seed Trade Census

Directory of Commercial Non-Hybrid Vegetables in the United States 2015