Brief History of Vegebouquets
On the dawn of the first civilizations, vegetables and fruit were often considered as a valuable sacrifice for the gods. The worshipers would often gift their best and most beautiful fruit and vegetables to their gods of choice. And, of course, they tried to arrange their donations in an aesthetically appealing form thus creating the first ever vegebouquets.
The Egyptians were arguably the first to fully appreciate the beauty of vegetables and fruit.
Food religious offering in Ancient Egypt approx. 4,000 years ago. One may recognize figs, leek, melons among other fruit and veges.
In Ancient Greece, a particular vegetable was usually dedicated to a particular god. For this reason, vegebouquets were often made of a single vegetable or fruit. For example, at a festival in the Greek city of Delphi, locals would bring leek as an offering to Leto, the goddess of motherhood. Curiously, the person having brought the biggest leek, received a portion of the entire offering as a reward.
Mystical properties of vegebouquets survived well into the Medieval Era. In Middle Ages, Europeans often used vegebouquets as a defense against evil spirits and other creatures of the dark. Garlic becomes a common ingredient of vegebouquets due to its allegedly. superior anti-vampire effect. By the way, here is out take on anti-vampire vegebouquet
A garlic vegebouquet, 1506 CE.
Vegebouquets become especially popular at wedding ceremonies due to prevailing superstitions. For example, it was believed if a bride carried sage, she'd become wise; if she carried dill, she'd become lusty; etc.[4,5]
In the Modern Era, vegebouquets largely turned into centerpieces at various events and functions.[6,7] Some of such centerpieces were so large, and their style being so eclectic, they very much resembled the offerings to the ancient gods. Check this one out.
Gigantic size of the vegebouquets was a prominent feature of the epoch. Even regular handheld vegebouquets had a tendency to be rather huge. A London magazine describing a vegebouquet made of carrots, radishes, Brussel sprouts, kale and other veges concludes that "the whole, including the holder, measured fifteen inches [38 cm] in diameter". Just compare it to the contemporary bouquets rarely exceeding 20-25 cm in diameter.
The main theme of XX century was the miniature size and simplicity of vegebouquets.
A vegetable bouquet of the early XX century. Ingredients: peas, beans, tomatoes, lettuce, carrots, potatoes, sage. Colourised with colorize-it.com
Vegebouquets gained popularity in the US artistic circles and were occasionally presented to artists after a performance as a sign of appreciation.[10,11]
In the second half of the century, vegebouquets were often used to promote healthy eating habits.
A poster by the US National Health Institutes
In the end of the century, after the US President expressed his dissatisfaction with the taste of broccoli, the broccoli producers attempted to change his mind by presenting a simple broccoli bouquet to the First Lady.
Barbara Bush with a vegebouquet in 1990
Contemporary vegebouquets are of all sorts and shapes. Vege artists keep relentlessly exploring new shapes and combinations. In the recent year, it became trendy again to replace flowers with vegetables at wedding ceremonies.  
Here are a few distinct trends of today's vegebouquets: (1) Bright but minimalist bouquets; (2) Extravagant and colourful bouquets decorated with some flowers and sometimes even french macarons (3) Zero-waste sustainable bouquets minimising effect on the world's resources.
 Wolf D. Storl (2016). A curious history of vegetables. North Atlantic Books, ISBN 9781623170400, pp. 152-153.
 González, J.A., García-Barriuso, M., Pardo-de-Santayana, M. et al. (2012) Plant Remedies against Witches and the Evil Eye in a Spanish “Witches’ Village.” Economic Botany (2012) 66: 35. doi:10.1007/s12231-011-9183-y
 Floridus Macer (1506). De viribus herbarum (lat.). Geneve, Switzerland, ISTC No.: im00005000.
 Valerie and Lyle MacPherson (2012). The Medieval Wedding Planner. Preview by GoogleBooks
 C. M. Hovey (edit.) (1846). The Magazine of Horticulture, Botany, and All Useful Discoveries and Improvements in Rural Affairs, Volume 12. Hovey and Company, p. 411.
 US Department of the Interior (1900) Annual Reports of the Department of the Interior ... [with Accompanying Documents]. U.S. Government Printing Office, p. 200.
 Michigan State Horticultural Society (1885). Annual Report, Issue 14, p. 302.
 The Strand, Volume 32 (1906), published by G. Newnes, p. 480.
 Proceedings of the local branches (1928). Journal of the American Pharmaceutical Association, 17(6), Wiley Subscription Services, Inc., pp. 599-602.
 Krauss, E. C. (1937). Expert Witnesses. California and western medicine, 46(4), 286.
 J. Ida and K. Spikings (1979). Raising a new consciousness [nutrition education, California]. Nutrition News (USA).
 Alexander Theroux (2017). Einstein's Beets. Fantagraphics Books, ISBN 9781606999769, p. 589.