Grafting the Grape: American Grapevine Rootstock in Missouri and the World

The Grafting the Grape exhibition explores the various American grape species that are most used in viticulture, grafting, and winemaking, and how they were and continue to be used by the Native peoples of Missouri. Today, these American grapevine rootstock species continue to provide research challenges as scientists study and understand how the rootstock plants affect the scion plant’s berries and chemical compounds (which affect the final wine product) as well as how climate change is impacting the future of viticulture around the world. You can see a few examples of grafted and own-rooted (ungrafted) grapevines in the test plots of the Garden’s William T. Kemper Center for Home Gardening.

Grapes and the Garden

Wine has long been a part of the material history of the Missouri Botanical Garden. Garden founder Henry Shaw (1800-1889) was a dedicated oenophile—a connoisseur of wines—as well as a supporter of botanical science and a successful businessman in St. Louis. The Garden’s first botanical advisor, Dr. George Engelmann (1809-1884) aided Shaw in developing the Garden into a scientific research institution; he spent a significant time focusing on the identification and understanding of the American grapevine species when he came to St. Louis. Engelmann spent a great deal of time studying grapes, and specifically native American grapes, writing a number of publications on the varieties and classifications of grape species. Today, the Garden’s Center for Home Gardening has a plot of several American grapevine plants and hybrids growing as part of a research project started and managed by botanist Dr. Allison Miller, professor at St. Louis University and principal investigator at the Danforth Plant Science Center. Learn more in this previous post on the Garden blog.

The maquette of this bench featuring Henry Shaw and grapevines is on view in the Museum exhibition; artist, Paul T. Granlund (1925–2003); photo by Tom Incrocci

What’s in a grape?

The grape family, Vitaceae, is mostly distributed in the pantropical areas in Asia, Africa, Australia, the neotropics, and the Pacific islands, with a few genera in temperate regions. There is strong support for Vitaceae as the earliest diverging lineage of rosids—a major group of flowering plants including apples, walnuts, and chocolate. Vitis is a relatively ancient clade, and its evolution has been shaped by Earth’s climatic fluctuations and continental drift; a clade is a natural group of organisms that are composed of a common ancestor and all its lineal descendants. The American Vitis species that the Grafting the Grape exhibition explores have an ancient history. These grapevines and berries were first harvested by the Indigenous peoples who first inhabited the North American continent, and who lived or traveled through the lands that are now designated as the boundaries of the state of Missouri. Throughout the period of European colonization and settlement, Indigenous Americans continued to use these species throughout the North American continent and today, these native grapes are one of many native American plants that play a role in Indigenous culture and foodways. We’ll explore these uses and roles by Indigenous Americans in a future blog post.

Earliest evidence of ancient winemaking in the Republic of Georgia

The country of Georgia, in the south-eastern corner of Europe, is located on an isthmus between the Black and Caspian Seas, a crossroads of diverse regional ecosystems, cultures and languages. The rugged, mountainous terrain has contributed to the region’s high biocultural diversity, harboring biological and cultural systems that have co-evolved over millennia. In addition to its high levels of plant diversity, Georgia is home to an ancient agricultural practice, and the center of domestication for multiple food crops including wheat, legumes, and fruits, such as grapes, which includes one of the world’s most desirable agricultural commodities, wine made from Vitis vinifera. Documented in the archaeological record as the earliest region of winemaking (as early as 6000 BCE), Georgia has a long history and association with wine in its culture, including its use in Christian ritual and traditions; today Georgia is also a young winemaking country as its industry has been reborn since the Soviet era. Additionally, it remains common for Georgian families to grow their own grapes and make their own wine. One of the most identifiable tools and symbols of Georgian winemaking is the vessel used to make, store, and age the beverage, the kvevri or qvevri, which is still used in modern Georgian wine-making, and can range in size from 5 to 3500 liters. We’ll share more about the country of Georgia and its winemaking history and current industry in a future blog post.

Backyard Home-Garden and Rkatsiteli Vineyard Nearing/Awaiting Harvest, Ujarma, Georgia, by Aurora Prehn, ca. 2019

Winemaking 101

Wine is fermented grape juice. At its simplest, wine is made by crushing grapes and allowing the natural yeasts present on the skins to come in to contact with the natural sugars present in the juice. No other human intervention is needed: crushed and fermented like this, any grapes will make wine. Fermentation stops at an alcohol concentration of about 16%—at this point, yeast cannot tolerate the high level of alcohol, they die, and fermentation stops. There are three types of wines: table, sparkling, and fortified. If fermented to dryness, the alcohol of table wines falls within the 11-15% alcohol concentration range. Sparkling wines are the ones with bubbles—such as Champagne—which are achieved by placing wines through a second fermentation in bottles, after which the bottle is opened to eliminate excessive pressure, and then resealed; these have alcohol concentrations around 12%. In fortified wines, brandy (a distillate of wine) is added to make the alcohol content higher (16 to 23%). After fermentation and before bottling, wine is clarified by filtration and then microbially stabilized. Wine flavors can continue to change while the wine is stored in wooden barrels, stainless steel tanks, and glass bottles. Red wines are fermented with the skins. After crushing the grapes, the combination of juice and skins is known as “must.” The must is fermented, and then pressed to retain only the fermented liquid; the grapes skins are removed. White wines are fermented after the must has been pressed to extract the juice. No skins are present during the fermentation with the resulting wine considered “white.” Rosé wines are white wines made with red grapes. The must is pressed when its color is the desirable shade of rose. After pressing, the skins are removed and the fermented liquid retains the desirable shade of rose.

The material culture of wine

The making, storage, presentation, and drinking of wine offers a long historical legacy of objects created to enjoy this unique beverage. Presses, barrels, corks, and corkscrews are various tools used to make and store wine so that it can be preserved and aged to enhance the flavor and experience of tasting wine. It is the history and development of glass that has been used to great effect in the manufacture of decanters and glasses to enjoy wine through the senses of vision, scent, and taste. Decanters are formal containers for wine and spirits that allow for the color of the liquid inside to be appreciated at a glance, but also to perform the function of ‘decanting’ wine by aerating, or exposing the wine to oxygen; this process enhances the flavors and releases the gasses that developed during the aging, or refining, process, and can be said to let the wine ‘breathe.’ Wine glasses come in a wide variety of shapes and sizes as each type of wine glass shape is suited to a specific type of wine or wine-based drink. The earliest forms of wine glasses were developed by the ancient Romans, who enjoyed being able to see the color of their wine through their transparent and almost-colorless glass vessels. 15th-century Venetian glassblowers crafted the shape of the wine glass—the base, stem, and bowl—that is the standard design today. Specialized glasses were developed for drinking different wine-based drink, such as bubbly Champagne, or cordials for fortified wines (such as sherry and port), and liqueur glasses for spirits, such as brandy—a distillate of wine. The shapes of the bowls allow for the fragrance, flavors, and carbonation to be viewed and contained, so that scent and the taste of the beverage is experienced at its fullest.

A collection of wine glasses lent to the exhibition by Garden President Dr. Peter Wyse Jackson; photo by Virginia Harold

A botanist and an entomologist saved wine for the world

For millennia, humans have cultivated wine as a drink and for social, religious, and economic power. Drunk for social communion, held as a symbol of elite status, and offered in ritual ceremonies, wine made from the grapes of Vitis vinifera has been shipped and transplanted around the world, with the earliest winemaking traditions found in central Asia thousands of years ago. Today, wine enthusiasts are very familiar with the world-renowned wines that are grown in Europe, South America, South Africa, Australia, New Zealand, and the United States. Yet, drinking wine from this grape species would not be possible today without the research, identification, and development of 19th-century Missouri botanists, entomologists, and viticulturists.

A key culprit in this agricultural innovation is the result of an insect, grape phylloxera, which found its way from the American Midwest to the vineyards of Europe in the 1850s; by the 1870s had devastated the wine grape crop there, attacking and feeding on the plant’s roots to the point of killing the plants completely. It was the work of the Dr. George Engelmann and the Missouri state entomologist Charles V. Riley, that identified the lifecycle of grape phylloxera (as evidenced on the native American grapevine plants and rootstock) as the cause of the devastation.The scientific name of grape phylloxera Daktulosphaira vitifoliae means “finger-ball of vine leaf.” This insect is barely perceptible by the naked eye, yet it causes an immense impact to the grapevine plants that humans have been using to make wine for millennia. Endemic to North America, Closely related to aphids, this insect belongs to the family Phylloxeridae in the order Hemiptera (true bugs) which share similar arrangements of sucking mouthparts; most phylloxerid species produce galls on dicotyledonous plants, which are seeds that have two embryonic leaves or cotyledons. The life cycle of grape phylloxera is complex, due to its four different forms, all of which can reproduce either from sexual or parthenogenetic reproduction (reproduction without ovum fertilization), and they can be found underground or on the leaves of the grapevine. Grape phylloxera’s ability reproduce asexually exponentially is one reason it devastated European vineyards so quickly.

The four forms are: the wingless, root-feeding form (radicole); a winged, egg laying form (alate); a wingless, sexual form (fundatrix); and a wingless, leaf-galling form (gallicole). Due to its minute size, the presence of the gallicole, or wingless female is almost imperceptible if not for the distinctive galls that they form on leaves. Grape phylloxera galls are wrinkly pouch-like growths on the bottom of the leaf that also have very fine translucent hairs. The galls are approximately the size of a pea and at the worst point of infestation, can completely fill the underside of a leaf. Today, grape phylloxera can be controlled as part of an integrated pest management plan or with pesticides. There are few vineyards around the world that have not been touched by this insect; namely certain sections of Australia, the country of Chile, and the Mosel region of Germany. Several factors likely play a role as natural barriers to grape phylloxera infestation, including soil composition and geographical isolation.

Grafting’s the thing

The technique of grafting developed thousands of years ago, with some of the earliest cultivated orchards confined to fig, olive, pomegranate, grape, and date palms propagated from cuttings or division of root stock. Grafting developed because agriculturalists realized that growing new plants from seeds of existing trees did not breed true, therefore they developed grafting so that they would control the end result of the fruit tree. In North America, grafting was widely used in apple orchards, resulting in the discovery and creation of numerous apple variations. The grafting and propagation of apple and other fruit trees became essential to many settlers moving west as they colonized the continent.

Grafting is the deliberate fusion of two plants into one by cutting off the upper part of one plant (called the scion), typically a shoot or bud, and inserting it into the lower part of another, closely related species plant, (called the stock) that must always include the root system. When grafting, the scion will contain multiple buds, but only a single bud is grafted at a time. The only requirement for grafting and budding is viable cambium contact. The cambium is a single layer of cells located just below the bark. This area leads to the formation of the graft union of the scion and rootstock. Increased cambial contact (the more area that touches) between scion and rootstock increases the chances of success. There are multiple types of grafts, some of the most common are bud, cleft, or whip grafts; the whip graft is one of the oldest known methods of grafting techniques and offers the largest surface area contact between scion and rootstock, thereby making the greatest chance for the graft union healing to occur.

When the grape phylloxera infestation devastated European vineyards in the late 19th century by affecting the plant roots, and Engelmann and Riley identified the insect, they also worked with French and American viticulturists to provide the solution. This solution was to graft the European grapevine on to American grapevine rootstock, since the American plants were more resistant to phylloxera (there’s a chemical compound in the roots that makes it less tasty to the insect). To determine which classifications of vines were best suited, Riley sought out Engelmann, and using Engelmann’s knowledge and grapevine herbarium specimens, they figured out which species were best suited and orchestrated the export of resistant seedlings and grapevines to France. Riley found even more evidence in support of his solution when visiting the Isidor Bush-Meissner nursery in St. Louis where it was clear the European vines that had these insects on their roots would wilt and die when planted. The nursery created the Bushberg Catalogue, which also referenced Engelmann’s work, to offer hundreds of options to French wine growers for grafting. Thousands of vines were subsequently shipped to France from the Isidor Bush-Meissner nursery. Almost a decade later, their solution proved promising and would save the French wine industry and others as the pest spread. Now found throughout the world, the same solution to control the Phylloxera pest continues to this day. If you’d like to read more about this discovery and application, Christy Campbell’s book The Botanist and the Vintner: How Wine Was Saved for the World goes into this history with more detail.

The history of Missouri’s winemaking industry

There was a strong commercial interest to start an American wine industry from the moment European colonizers arrived in North America. Unfortunately, the European grape (Vitis vinifera) did not perform well or successfully to create wine in many early attempts in the colonies, except for those of the Spanish in what is today California; these results most likely because of harsh winter temperatures that damaged vines, and of grape phylloxera consuming the roots, but the colonists did not realize that at the time. In Missouri, V. vinifera was not able to be grown either, so immigrants to the region in the early 19th century used the native grapes they found to make wine, being able to grow a thriving industry of winemaking. However, on the whole, the wine produced by American grapes was not considered the most desirable in terms of wine connoisseurship, and it took many years before an American wine product using native grapes was developed that was taken seriously in terms of refinement in taste and palate.

Throughout the mid- to late 1800s, German farmers became known for their winegrowing, especially in Hermann, but also in Augusta (another predominantly German immigrant-settled area), most often using the Norton grape (Vitis aestivalis); by the 1850s there were about 60 wineries. Because of the land’s climate, soil, and geography, Missouri was especially suited to growing grapes that preferred high sun exposure, rocky soil, and long, hot summers. Missouri’s multitude of rivers—the Mississippi, Missouri, and Gasconade—also helped the agriculture. In the mid-1800s, when several Native American nations in the Louisiana Purchase territory were being relocated from their lands to other parts of the country, German-Missouri farmers began creating wineries on these lands. They used farming strategies to aid in growing vineyards, including lime to reduce the acidity of the soil; soil pH ranges from acid [0] to alkaline [14], with [6] being ideal for growing grapes. The wineries were largely dominated by German immigrants or their first-generation children, though Italian immigrants also came to the region in the late 1800s and also developed wineries in the St. James area in Missouri. Missouri wineries continued to develop and flourish, leading to Missouri’s rank as one of the top four wine-producing states in 1904.

Despite Missouri wineries’ successes, the 18th Amendment to the Constitution was passed in 1919 in the United States, prohibiting the manufacturing, selling, and transporting of intoxicating beverages, leading to the downfall of the wineries. During the Prohibition era, Missouri had only one registered winery, which remained open for religious purposes and was run by Jesuits who produced wine for the Roman Catholic Mass. Some wineries tried to produce other crops, such as mushrooms, but most closed entirely, and these closings were overseen by government agents, who destroyed the vineyards and equipment. After Prohibition ended in 1933, a few wineries began slowly reopening, numbering only 12 wineries in 1937.

During the 1980s, there was a new tax on wine which allowed for the establishment of the Missouri Wine and Grape Program. Missouri State University and local viticulturists worked to restore Missouri’s wineries and set up experiments to see which grapes are best suited for Missouri’s climate; they determining the Norton-Cynthiana grape was resilient, complex to cultivate, and easily used in blends. At the same time, the United States Alcohol and Tobacco Tax and Trade Bureau began to designate “American Viticultural Areas” (AVAs), regions known for their geographic features making them ideal for growing grapes for wine. The first designated AVA was Augusta, Missouri (9600 acres) in 1980 due to its long, distinguished history of beneficial soil, healthy climate, and tasty wines. In 1986, the Missouri Ozark Mountain region (3.5 million acres extending into Arkansas and Oklahoma) and in 1987 the Ozark Highlands (1.280,000 acres), the region around St. James were also designated as AVAs. Also in 1987, the Hermann area (51,200 acres) was AVA designated.

Today, Missouri contributes to the United States’ wine and grape industry, and the state’s economic impact includes providing over 28,000 jobs and serving almost 1 million tourists in the years just prior to the 2020 pandemic. Globally, the US is the largest wine-consuming country (in total hectoliters consumed, not per capita), consuming 2019 33 million hectoliters of wine (a hectoliter is equal to one hundred liters) in 2019. The second largest wine-consuming country is France; in 2019, they consumed about 26.5 million hectoliters of wine. In terms of production, Italy, France, and Spain reside at the top. Italy produced about 47.5 million hectoliters in 2019. The total hectoliters produced internationally equates to 260 million in 2019.

Display of wine bottles in the exhibition; photo by Virginia Harold

Tendrils of grapevine science in contemporary art

An important intersection to the Grafting the Grape exhibition is the contemporary multi-media artworks produced by three artists who were specially commissioned to create their artistic interpretations of this material, both historic and scientific, on grapevines, grafting, wine, and the Missouri Botanical Garden. You’ll learn about the artists and their work in a future blog post.

Artist Dornith Doherty, renowned for her photographic work on seeds and global seedbanking, created three works in her series Roundabout (Circuition). Inspired by the story of how Dr. George Engelmann and Missouri state entomologist Charles Valentine Riley confirmed the identification of the grape phylloxera insect infestation in the European vineyards in the 1870s, and the work of Dr. Allison Miller and her NSF-funded project Vitis Underground that investigates the relationship between scion grapevines and rootstock in viticulture, Dornith Doherty created one photographic series, and two short films highlighting these intersections. Her series of images features highly magnified scanning electron microscope images of phylloxera galls. Printed on metal panels, these lustrous sepia toned photographs make reference to the mid-19th century, a time when photography was invented and the phylloxera blight occurred.

Inspired by nature and climate change, artist collaborators Lei Han and Lorraine Walsh who have worked together on many digital artwork projects, focused their work for Grafting the Grape on environmental shifts as seen through the seemingly disparate practices of ancient horticultural grafting techniques and contemporaneous machine learning (a subset of artificial intelligence). The two methods share a paradoxical trait: grafting propagates and machine learning backpropagates. And this symbiotic biological approach in grafting is uncannily mirrored with algorithmic machine learning processes. They created one sculpture, one series of drawings, two series of digital images, and three series of short films for the exhibition. Their art focuses on the native grapevine species Missouri Vitis aestivalis (also known as the Norton grape) and the process of this mediation in order to bring a fruitful awareness of the significant effect climatic change has on life. The BudBurst print editions capture flowering grapevines against a palette of colors that represent a warming climate. Included here are the original photographs, drawings, and some machine learned imagery from image databases of botanical illustrations utilizing the Biodiversity Heritage Library (BHL), the world’s largest open access digital library for biodiversity literature and archives.

Wine has long been a part of the history of the Missouri Botanical Garden, and it continues to play a role in the work the Garden does today. Grateful thanks to all of these contributors and collaborators to the Sachs Museum’s exhibition and programs who shared their expertise, passion, and creativity on grapes, grapevines, and wine for this project. The Garden’s Herbarium collects and preserves many Vitis species found around the world, and holds the legacy of the work Dr. George Engelmann started in the 19th century on the American Vitis species. The Garden’s William T. Kemper Center for Home Gardening has partnered with Dr. Allison Miller on the Vitis Underground project, and planted native American vines as well as French-American grapevines for use in this research project (those grapes are on view at the Kemper Center today). The Garden’s William L. Brown Center, Tower Grove House, Peter H. Raven Library, and Archives have all shared their collections in this exhibition.

Nezka Pfeifer
Museum Curator, Stephen and Peter Sachs Museum

Grateful thanks to the sponsors of the exhibition: The Thomas A. Kooyumjian Family Foundation, Tony & Cindy Kooyumjian, National Science Foundation Plant Genome Research Program 1546869, and Missouri Botanical Garden’s Corporate Council.

Special acknowledgments to all contributors to the exhibition, including everyone already mentioned in the text, as well as: Keith Duncan, Laura Klein, Alex Roach, Michael J. Leonardelli, Aurora Prehn, Dr. Susan Kooiman, Emma Warner, Dr. Ian Thompson, Steffie Littlefield, Cyndy Keesee, Thomas F. Bush, David Maghradze, Tamar Maghradze, Marina Mosulishvili, Nana Bitsadze, Anzor Uzunashvili, Dr. Peter Wyse Jackson, Jim Solomon, Mary Merello, Sally Bommarito, Lauren Boyle, Fred Gauna, Tad Yankoski, Chris Hartley, Jennifer Smock, Robbie Hart, Aurora Prehn, Haley O’Toole, Doug Holland, Andrew Colligan, Mike Blomberg, Susie Cobbledick, and Garden designers Mary Shocklee and Ellen Flesch, and installation expertise by Moira Smith and Rachel Lebo.

Especial thanks to the Sachs Museum remote interns who contributed to the research, text, and illustrations of the exhibition: Alexandra Lebovitz, Megan Rossman, Anne Farrell, Natalia Granquist, Heather Sheppard, Danielle Griffin, Elias Larralde, Isobel Abbot-Dethrow, Eleanor Schulz, Kyra Tani Little, Edina Krantic, Charlotte Filiciotto, Anna Wachtel, Kimberly Schwartz, Yukeria Haywood, Mackenzie Shields, and Alex Arata.

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