Boxwood under Threat

“Boxwood blight invades North America,” reads the headline of an article that appeared in Science News in January 2012. Caused by Cylindrocladium buxicola—a fungus whose spores remain viable for several years and are easily dispersed by birds, moving visitors, wind, or even sprinklers—the disease manifests itself by dark or light brown spots or lesions on the leaves that eventually fall off. First reported in southern England in 1994, boxwood blight has since been devastating gardens across the world, from Europe to New Zealand. Recently, it has been described as “a significant concern for the ornamental horticulture industry” as well as “a growing threat to established landscapes and native ecosystems alike.”1

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Boxwood is a genus of evergreen shrubs that enjoys great commercial success as ornamental garden plants. Among its varieties and cultivars, the most popular is arguably English or common boxwood (Buxus sempervirens ‘Suffruticosa’), native to western and southern Europe, northwest Africa, and southwest Asia. In the United States—where this cultivated variety had been mass introduced on the wave of the early twentieth-century interest in European gardens—its sales, until recently, represented the greatest proportion (around 15%) among broadleaf evergreens, reaching an annual revenue of $126 million in 2014.2 A boxwood-flanked promenade, in the words of landscape architect Diane McGuire, was historically “the most common element found in almost every garden in the southern United States.”

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One of the finest among these, Dumbarton Oaks—designed by Beatrix Farrand beginning in 1921—includes three areas originally named after this shrub: the Box Walk, the Box Terrace (now called Urn Terrace), and the Box Ellipse (later replanted with hornbeam). According to McGuire, boxwood—along with yew and holly—was one of the most characteristic plants in Farrand’s palette, serving as “the embodiment of our deepest associations with the gardens of the Old World and with the cottage gardens of England.”3 It was precisely these historical roots of North American garden culture, not just the commercial future of a ubiquitous ornamental shrub, that the spread of boxwood blight put under threat.

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“A Plant Known to Everybody”

How did boxwood come to represent the lasting legacy of the European garden tradition? Its historical fortunes hardly amount to a dazzling story of overseas exploration, important discoveries, or economic exploitation—the “big business” of early modern botany, to use Daniela Bleichmar’s phrase.4 An integral element in the Mediterranean maquis—scrubland vegetation—boxwood has been familiar to Europeans for many centuries. Sixteenth-century Italians considered it “a plant that is known to everybody, since it abundantly grows all over Italy”; while in England it was habitually found among “sundry waste and barren hills.”5 Boxwood’s adaptation to garden design went back to antiquity. Roman author and politician Pliny the Younger mentions its use in his villa “in Tuscis,” where, cut into various shapes representing figures and letters, it served as the main material for elaborate topiary work.6 This malleability of boxwood, the ease with which it lent itself to pruning, was particularly valued by the ancients, making it an indispensable and versatile medium for the creation of green architecture and sculpture.

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Ancient Love vs. Early Modern Dismissal

Given this close association of boxwood with the gardens of Roman antiquity, it might come as a surprise that sixteenth-century Italian theorists disparaged its use, preferring instead other plants of similar size and texture, such as myrtle and viburnum (Viburnum tinus). Horticultural writer Girolamo Firenzuola, for example, recognized the ancient custom of using boxwood and laurel in making espaliers and hedges, noting, however, that these plants were less favored in his own day. Oranges, lemons, and citrons, he believed, were more “pleasing to the eye”; and, in creating a garden, one could easily dispense with boxwood altogether.7 A later author, Giovan Vettorio Soderini, similarly acknowledged boxwood’s popularity in antiquity due to its “obedience to the clippers,”8 which allowed gardeners to “give it whatever form one might want” to produce “graceful animal and human figures, ships, vessels, towers, walls, fortifications, houses, obelisks, columns, tables, architraves, arches, pilasters, and seats.”9 Along with cypress, it was supposed to instill a melancholy mood, while in winter its roots often became infested with poisonous snakes.10

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The real issue with boxwood was what sixteenth-century English physician John Gerard described as the “evil and loathsome smell,” which, according to Soderini, was not only “annoying,” but could give one headaches as it “infested the air.”11 To mitigate the odor, the recommended solution was to plant boxwood in combination with other strongly scented evergreens such as myrtle, mastic, and rosemary.12 These mixed hedges benefitted from the robust texture of boxwood. Boxwood’s other selective use, also due to its thick and dense foliage, was planting it in thicket-like bird trapping grounds, ragnaie.13 Yet, compared to other plants that could serve analogous purposes or occupy the same garden spaces, boxwood, in Soderini’s words, was “valued little or not at all.”14

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Boxwood’s potential medicinal applications met with a similar lack of enthusiasm. Despite an attempt by Amato Lusitano, a sixteenth-century Portuguese Jewish physician, to prove that boxwood was a native European analogue of guaiacum and could, therefore, potentially cure syphilis, the general consensus—endorsed by the leading writer on materia medica, Pietro Andrea Mattioli—was that it “had no use in medicine.” Lusitano’s claim was dismissed as “vain and foolish,” which “could in no way be acceptable to doctors.”15 Such pronouncements against boxwood, which was considered of “no physical use among the most and best physicians,” were sustained by the Englishman John Parkinson (who, however, noted that its leaves could be given to horses as a cure for botfly larvae); Gerard raged against “foolish empirics and women leeches” who “minister it against apoplexy and such diseases.”16 This negative opinion continued to pervade early modern medical thought, while boxwood’s known curative properties, especially as a styptic, generally remained ignored.

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A Crafty Kind of Wood

If Mattioli and Parkinson considered boxwood primarily an ornamental plant “well adapted to weaving espaliers in gardens and dividing one space from another,”17 its slow growth rate had important industrial implications. Hardened through the process of gradual maturation, its timber acquired such valued qualities as durability and density, making it indeed similar to guaiacum.18 Boxwood, according to Soderini, could last “forever” and “was good for the printing industry and other fine woodwork.”19 Since it lent itself well to lathing, Gerard considered it particularly suitable for “dagger hafts, boxes, and suchlike uses.”20 Sixteenth-century Netherlandish rosary beads—true miracles of late Gothic craftsmanship—testify to these remarkable properties. These exquisite boxwood carvings, which often measure less than two inches in diameter, could represent on a tiny scale multi-figure biblical scenes without losing any of their dramatic intensity.

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Boxwood Reinstated

The vindication of boxwood as an essential garden plant took place in late sixteenth-century France, almost a millennium-and-a-half after its enthusiastic mention by Pliny. In horticulture, this moment marked the introduction of parterres de broderie characterized by low, manicured hedges that imitated embroidery patterns. Boxwood—along with myrtle, lavender, juniper, and rosemary—was deemed particularly well-adapted to making the borders of plant beds, within which were planted marjoram, thyme, hyssop, pennyroyal, sage, chamomile, mint, violets, marguerites, basil, and other herbs and flowers.21 Horticultural theorist Olivier de Serres, in Théâtre d’Agriculture (first published in 1600), emphasized boxwood’s resistance to the effects of weather and time and its little need for care, favorably contrasting it with myrtle, which was less suitable to colder climates. These properties, he believed, would have made boxwood a perfect garden shrub if not for the lack of “good scent,” having instead an odor “strong, unwelcome, and unpleasant, which causes headaches.”22

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In practical terms, borders involving a combination of different shrubs as described by De Serres needed to be regularly replanted. If they were to last longer, his advice was to use boxwood alone regardless of its smell.23 The advocate of this method was royal gardener Claude Mollet, who was credited with inventing parterres de broderie and supplying their illustrations for De Serres’s treatise Théâtre d’Agriculture. Coming from a family of gardeners, Mollet wrote from the perspective of a professional horticulturist (who among other things, he believed, was supposed to be well-versed in astrology). A committed champion of boxwood, he emphasized the volatility of the French climate affected by two “extremes,” “the great heat and the great cold,” which caused the “nuisance and expense of having to redo and replant garden compartments once every three years.”24 Mollet’s solution was to reduce the composition of borders solely to boxwood, which he started to implement for King Henri IV in 1595 in the gardens of Saint-Germain-en-Laye, Monceaux, and Fontainebleau; decades later, they would still remain in “good shape.”25 The species that he particularly praised was nain (dwarf) boxwood, which did not grow as tall as other varieties and had smaller leaves, but showed the same resistance to freezing and heat.26

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A Global Garden Element

Mollet’s planting and stylistic innovations gained the fullest expression in the gardens of Versailles—whose boxwood parterres, berceau (bowers), and a labyrinth were created for Louis XIV by André Le Nôtre. From here they spread throughout Europe and beyond. Elaborate topiary work, for example, was one of the attractions of the European-style imperial garden of Yuanming Yuan (Old Summer Palace) in Beijing, designed in the eighteenth century by Jesuit Giuseppe Castiglione. Italy continued to be resistant to the wholesale adoption of boxwood but, in the end, the shrub’s triumph was complete. If, toward the end of the eighteenth century, agricultural reformer Marco Lastri had thought that the most characteristic plants growing in Italian gardens were “fruit trees, citruses, and flowers,” over a hundred years later, American novelist Edith Wharton (Beatrix Farrand’s aunt) extolled Italy’s “old garden-magic” that she identified with green “box-parterres” and “box-edged plots.”27 Even the once-reviled smell became a feature of Old World nostalgia. In her autobiography, Wharton would fondly recall her friend Vernon Lee’s “homely box-scented garden,” an epitome of the quaint European charm consciously cultivated by members of the Anglo-American community in Florence.28

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Closely connected with these expatriate circles was British landscape architect Cecil Pinsent, another contemporary of Farrand’s, who extensively used boxwood in his landscaping projects. Most famous among his gardens was the Villa I Tatti in Settignano, Italy, designed for the American art historian and connoisseur Bernard Berenson. Another celebrated work was the lower terrace of the fifteenth-century Villa Medici in Fiesole that Pinsent furnished with a “carpet of box parterre,” regarded by landscape historian Geoffrey Jellicoe as fully integral to the historic character of the property.29 Popularized by postcards and book illustrations, Pinsent’s design became an iconic image of the Italian Renaissance garden, with its boxwood geometry—purposely projected into the Medicean age—serving as a visible bridge between distant antiquity and a more recent but equally glorious past.

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Humble Yet Resilient

Deeply invested with cultural symbolism, boxwood represents the rich legacy of the formal gardens of Europe characterized by geometric layout, controlling vistas, and ambitious scale. Characterized by climate resistance and malleability, it has served not merely as plant material, but a key medium of stylistic expression across the globe, reflecting a horticultural tradition with origins in antiquity. The story of boxwood is that of a humble yet resilient plant, which, after centuries of disparagement and neglect, succeeded in taking over the garden world. Whether or not it would be able retain this hard-earned preeminence as the most sought-after ornamental shrub, only time can tell.30

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References

  1. Nicholas LeBlanc, Catalina Salgado-Salazar, Jo Anne Crouch, “Boxwood blight: an ongoing threat to ornamental and native boxwood,” Applied Microbiology and Biotechnology 102 (2018): 4371, DOI:10.1007/s00253-018-8936-2 

  2. Nicholas LeBlanc, Catalina Salgado-Salazar, Jo Anne Crouch, “Boxwood blight,” with reference to USDA-National Agricultural Statistics Service Census of Agriculture 2014 reports, https://www.agcensus.usda.gov. English or European boxwood is the same species (Buxus sempervirens) as American boxwood. There are no boxwood species native to the United States. The centers of diversity for the genus are in Western Europe, Northern Africa, and Asia (Buxus microphylla). 

  3. Diane Kostial McGuire, ed., Beatrix Farrand’s Plant Book for Dumbarton Oaks (Washington, DC: Dumbarton Oaks, 1980), xiii. 

  4. Daniela Bleichmar, “Botanical conquistadors: the promises and challenges of imperial botany in the Hispanic Enlightenment,” in The Botany of Empire in the Long Eighteenth century, ed. Yota Batsaki, Sarah Burke Cahalan, and Anatole Tchikine (Washington, DC: Dumbarton Oaks, 2016), 35. 

  5. Pietro Andrea Mattioli, Discorsi (Venice: Valgrisi, 1563), 138. Click here for full book; John Gerard, The Herball or general Historie of Plantes (London: Norton, 1597), 1225. Click here for full book. 

  6. Pliny the Younger, Letters, V.6. 

  7. Girolamo Firenzuola, “La grande arte della agricoltura,” in Alessandro Tagliolini, “Girolamo Firenzuola e il giardino nelle fonti della metà del Cinquecento,” in Il giardino storico italiano, ed. Giovanna Ragionieri (Florence: Olschki, 1981), 304. 

  8. Giovan Vettorio Soderini, Opere, ed. Alberto Bacchi della Lega (Bologna: Romagnoli dall’Acqua, 1902–7), III:52, 245, 251, 343. 

  9. Giovan Vettorio Soderini, Opere, III:254. 

  10. Girolamo Firenzuola, “La grande arte della agricoltura,” 304; Giovan Vettorio Soderini, Opere, III:254. 

  11. John Gerard, Herball, 1226; Giovan Vettorio Soderini, Opere, III:343. 

  12. Giovan Vettorio Soderini, Opere, III:254, 255; Girolamo Firenzuola, “La grande arte della agricoltura,” 304. Cf. Claudia Lazzaro, The Italian Renaissance Garden: From the Conventions of Planting, Design, and Ornament to the Grand Gardens of Sixteenth-Century Italy (New Haven and London: Yale University Press, 1990), 26, 291–2n.17. 

  13. Giovan Vettorio Soderini, Opere, III:295, 303, 343; Bernardo Davanzati, Toscana coltivazione delle viti e delli arbori (Florence: Giunti, 1622), 32. Click here for full book. 

  14. Giovan Vettorio Soderini, Opere, III:255. 

  15. Pietro Andrea Mattioli, Discorsi, 138; John Parkinson, Paradisi in sole paradisus terrestris (London: Lownes and Young, 1629), 606, reporting the same opinion. Click here for full book. Cf. Amato Lusitano, Curationem medicinaliam centuriae septem (Bordeaux: Vernot, 1620), 639–640. Click here for full book. 

  16. John Parkinson, Paradisi in sole, 606; John Gerard, Herball, 1225. 

  17. Pietro Andrea Mattioli, Discorsi, 138; cf. John Parkinson, Paradisi in sole, 606–607. 

  18. Giovan Vettorio Soderini, Opere, I:182. 

  19. Giovan Vettorio Soderini, Opere, I:151, 175. 

  20. John Gerard, Herball, 1225. 

  21. Olivier de Serres, Théatre d’agriculture (Paris: Saugrain, 1617), 506, 529. Click here for full book; Jacques Boyceau, Traite du jardinage (Paris: Vanlochom, 1638), 66. Click here for full book. 

  22. Olivier de Serres, Théatre d’agriculture, 506, 529. 

  23. Olivier de Serres, Théatre d’agriculture, 529. 

  24. Claude Mollet, Théatre des jardinage (Paris: De Sercy, 1663), 201–202. Click here for full book. 

  25. Claude Mollet, Théatre des jardinage, 202–203. 

  26. Claude Mollet, Théatre des jardinage, 203. 

  27. Marco Lastri and Giuseppe Del Rosso, L’Osservatore fiorentino sugli edifizj della sua patria (Florence: Ricci, 1821), III:106 (orig. ed. 1797). Click here for full book; Edith Wharton, Italian villas and their gardens (New York: The Century Co., 1904), 13 and passim. Click here for full book. 

  28. Edith Wharton, A backward glance (New York, London: D. Appleton-Century Company, 1934), 130. 

  29. Geoffrey Jellicoe, “Italian Renaissance gardens,” Journal of the Royal Society of Arts 101 (1953): 182, http://www.jstor.org/stable/4136501 

  30. Both American and English boxwood are highly susceptible to boxwood blight, the latter perhaps owing to its compact, dense habit, which restricts air movement allowing foliage to remain wet for longer periods and trapping detritus in the interior of the plant. The cultivars of Buxus microphylla and Buxus harlandii, both native to Asia, show higher levels of resistance to the disease. I am grateful to Jonathan Kavalier, Director of Dumbarton Oaks Gardens, for this information.