Asparagus, or garden asparagus, folk name sparrow grass, scientific name Asparagus officinalis, is a perennial flowering plant species in the genus Asparagus. Its young shoots are used as a spring vegetable.
It was once classified in the lily family, like the related Allium species, onions and garlic. However, genetic research places lilies, Allium, and asparagus in three separate families—the Liliaceae, Amaryllidaceae, and Asparagaceae, respectively—with the Amaryllidaceae and Asparagaceae being grouped together in the order Asparagales. Sources differ as to the native range of Asparagus officinalis, but generally include most of Europe and western temperate Asia. It is widely cultivated as a vegetable crop.
Asparagus is a herbaceous, perennial plant growing to 100–150 cm (40–60 in) tall, with stout stems with much-branched, feathery foliage. The "leaves" are in fact needle-like cladodes (modified stems) in the axils of scale leaves; they are 6–32 mm (1⁄4–1 1⁄4 in) long and 1 mm (1⁄32 in) broad, and clustered four to 15 together, in a rose-like shape. The root system is adventitious and the root type is fasciculated. The flowers are bell-shaped, greenish-white to yellowish, 4.5–6.5 mm (3⁄16–1⁄4 in) long, with six tepals partially fused together at the base; they are produced singly or in clusters of two or three in the junctions of the branchlets. It is usually dioecious, with male and female flowers on separate plants, but sometimes hermaphrodite flowers are found. The fruit is a small red berry 6–10 mm (1⁄4–13⁄32 in) in diameter, which is toxic to humans.
Plants native to the western coasts of Europe (from northern Spain to northwest Germany, north Ireland, and Great Britain) are treated as Asparagus officinalis subsp. prostratus (Dumort.) Corb., distinguished by its low-growing, often prostrate stems growing to only 30–70 cm (12–28 in) high, and shorter cladodes 2–18 mm (3⁄32–23⁄32 in) long. It is treated as a distinct species, Asparagus prostratus Dumort, by some authors.
Asparagus has been used as a vegetable owing to its distinct flavor, and in medicine due to its diuretic properties and its purported function as an aphrodisiac. It is pictured as an offering on an Egyptian frieze dating to 3000 BC. In ancient times, it was also known in Syria and in Spain. Greeks and Romans ate it fresh when in season, and dried the vegetable for use in winter. Roman Epicureans froze its sprouts high in the Alps for the Feast of Epicurus. Emperor Augustus created the "Asparagus Fleet" for hauling the vegetable, and coined the expression "faster than cooking asparagus" for quick action.[Note 1]
A recipe for cooking asparagus is given in one of the oldest surviving collections of recipes (Apicius's third-century BC De re coquinaria, Book III). In the second century AD, the Greek physician Galen, highly respected within Roman society, mentioned asparagus as a beneficial herb, but as dominance of the Roman empire waned, asparagus' medicinal value drew little attention[Note 2] until al-Nafzawi's The Perfumed Garden. That piece of writing celebrates its purported aphrodisiacal power that the Indian Ananga Ranga attributes to "special phosphorus elements" that also counteract fatigue[dubious ].
Asparagus was brought to North America by European settlers at least as early as 1655. Adriaen van der Donck, a Dutch immigrant to New Netherland, mentions asparagus in his description of Dutch farming practices in the New World. Asparagus was grown by British immigrants as well; in 1685, one of William Penn's advertisements for Pennsylvania included asparagus in a long list of crops that grew well in the American climate.
Only young asparagus shoots are commonly eaten: once the buds start to open ("ferning out"), the shoots quickly turn woody.
Water makes up 93% of asparagus's composition. Asparagus is low in food energy and very low in sodium. It is a good source of vitamin B6, calcium, magnesium, and zinc, and a very good source of dietary fibre, protein, beta-carotene, vitamin C, vitamin E, vitamin K, thiamin, riboflavin, rutin, niacin, folic acid, iron, phosphorus, potassium, copper, manganese, and selenium, as well as chromium, a trace mineral that regulates the ability of insulin to transport glucose from the bloodstream into cells. The amino acid asparagine gets its name from asparagus, as the asparagus plant is relatively rich in this compound.
The shoots are prepared and served in a number of ways around the world, typically as an appetizer or vegetable side dish. In Asian-style cooking, asparagus is often stir-fried. Cantonese restaurants in the United States often serve asparagus stir-fried with chicken, shrimp, or beef. It may also be quickly grilled over charcoal or hardwood embers, and is also used as an ingredient in some stews and soups. In recent years,[when?] asparagus eaten raw, as a component of a salad, has regained popularity.
Asparagus can also be pickled and stored for several years. Some brands label shoots prepared in this way as "marinated".
Stem thickness indicates the age of the plant (and not the age of the stalk), with the thicker stems coming from older plants. Older, thicker stalks can be woody, although peeling the skin at the base removes the tough layer. Peeled asparagus will poach much faster. The bottom portion of asparagus often contains sand and soil, so thorough cleaning is generally advised before cooking. Plants bearing seeds produce spears that are smaller and thinner, and plants without seeds produce larger and thicker spears. Thickness and thinness are not an indication of tenderness or toughness. The stalks are thick or thin from the moment they sprout from the ground. 
Green asparagus is eaten worldwide, though the availability of imports throughout the year has made it less of a delicacy than it once was. In Europe, however, the "asparagus season is a highlight of the foodie calendar"; in the UK this traditionally begins on 23 April and ends on Midsummer Day. As in continental Europe, due to the short growing season and demand for local produce, asparagus commands a premium price.
White asparagus is very popular in Europe and western Asia. White asparagus is the result of applying a blanching technique while the asparagus shoots are growing. To cultivate white asparagus, the shoots are covered with soil as they grow, i.e. earthed up; without exposure to sunlight, no photosynthesis starts, and the shoots remain white. Compared to green asparagus, the locally cultivated so-called "white gold" or "edible ivory" asparagus, also referred to as "the royal vegetable", is believed to be less bitter and much more tender. Freshness is very important, and the lower ends of white asparagus must be peeled before cooking or raw consumption.
Only seasonally on the menu, asparagus dishes are advertised outside many restaurants, usually from late April to June. For the French style, asparagus is often boiled or steamed and served with Hollandaise sauce, White sauce, melted butter or most recently with olive oil and Parmesan cheese. Tall, narrow asparagus cooking pots allow the shoots to be steamed gently, their tips staying out of the water.
During the German Spargelsaison or Spargelzeit ("asparagus season" or "asparagus time"), the asparagus season that traditionally finishes on 24 June, roadside stands and open-air markets sell about half of the country's white asparagus consumption.
In India, especially in Maharashtra state it is not usually cultivated but it grows naturally in the farms during monsoon. Farmers from rural area and some tribal people use the young asparagus plants as a vegetable in their meals.
Since asparagus often originates in maritime habitats, it thrives in soils that are too saline for normal weeds to grow. Thus, a little salt was traditionally used to suppress weeds in beds intended for asparagus; this has the disadvantage that the soil cannot be used for anything else. Some places are better for growing asparagus than others. The fertility of the soil is a large factor. "Crowns" are planted in winter, and the first shoots appear in spring; the first pickings or "thinnings" are known as sprue asparagus. Sprue has thin stems.
A breed of "early season asparagus" that can be harvested two months earlier than usual was announced by a UK grower in early 2011. This variety does not need to lie dormant and blooms at 7 °C (45 °F), rather than the usual 9 °C (48 °F).
Purple asparagus differs from its green and white counterparts in having high sugar and low fibre levels. Purple asparagus was originally developed in Italy, near the city of Albenga and commercialized under the variety name 'Violetto d' Albenga'. Since then, breeding work has continued in the United States and New Zealand, creating the 'Pacific Purple' variety.
China is by far the world's largest producer: in 2017 it produced 7,845,162 tonnes, followed by Peru with 383,098 tonnes and Mexico with 245,681 tonnes. U.S. production was concentrated in California, Michigan, and Washington. The annual production for white asparagus in Germany is 57,000 tonnes (61% of consumer demand).
When grown under tunnels, growers can extend the harvest season. In the UK, it is estimated that the asparagus harvest season can begin as early as mid-February and continue into late autumn by growing cold-resistant cultivars under heated polytunnels. Furthermore, late season harvests can be achieved using 'reverse season growth' where spears are left to fern between March–August and harvested in September–October.
In Asia, an alternative approach to cultivating asparagus has been employed and is referred to as 'Mother Stalk Method' where three to five stalks per plant are allowed to develop into fern, while harvesting adjacent spears.
The green crop is significant enough in California's Sacramento–San Joaquin River Delta region that the city of Stockton holds a festival every year to celebrate it. In Michigan, Hart hosts an annual festival complete with a parade and asparagus queen; The Vale of Evesham in Worcestershire is the largest producer within Northern Europe, celebrating with the annual British Asparagus Festival involving auctions of the best crop, an "Asparagus Run" modelled on the Beaujolais Run and a weekend "Asparafest" music festival.
Many German cities hold an annual Spargelfest (asparagus festival) celebrating the harvest of white asparagus. Schwetzingen claims to be the "Asparagus Capital of the World", and during its festival, an Asparagus Queen is crowned. The Bavarian city of Nuremberg feasts a week long in April, with a competition to find the fastest asparagus peeler in the region; this usually involves generous amounts of the local wines and beers being consumed to aid the spectators' appreciative support.
Helmut Zipner holds the world record in asparagus peeling.
Vernacular names and etymologyEdit
A. officinalis is widely known simply as "asparagus", and may be confused with unrelated plant species also known as "asparagus", such as Ornithogalum pyrenaicum known as "Prussian asparagus" for its edible shoots.
The English word "asparagus" derives from classical Latin but the plant was once known in English as sperage, from the Medieval Latin sparagus.[Note 2] This term itself derives from the Greek aspharagos or asparagos, and the Greek term originates from the Persian asparag, meaning "sprout" or "shoot". Asparagus was also corrupted in some places to "sparrow grass"; indeed, John Walker wrote in 1791 that "Sparrowgrass is so general that asparagus has an air of stiffness and pedantry". The name 'sparrow grass' was still in common use in rural East Anglia, England well into the twentieth century.
In Turkish, asparagus is known as kuşkonmaz, literally "[a] bird won't land [on it]", in reference to the shape of the plant.
In India, especially in the state of Maharashtra, it is not cultivated but it grows naturally in the farms during monsoon season. Farmers from rural areas and some tribal people use asparagus as a vegetable in local cuisine.
It is called as 'Sasur / Susar Muli' (ससूर/ सुसर मुळी) in Marathi, a local language of the state of Maharashtra, India.
Mature native asparagus with seed pods in Saskatchewan, Canada
Effects on urineEdit
The effect of eating asparagus on urine excreted afterwards has long been observed:
[Asparagus] cause a powerful and disagreeable smell in the urine, as everybody knows.
asparagus... affects the urine with a foetid smell (especially if cut when they are white) and therefore have been suspected by some physicians as not friendly to the kidneys; when they are older, and begin to ramify, they lose this quality; but then they are not so agreeable.
A few Stems of Asparagus eaten, shall give our Urine a disagreeable Odour...
Asparagus "...transforms my chamber-pot into a flask of perfume."
Debate exists about the universality of producing the sulfurous smell, as well as the ability to detect it. Originally, this was thought to be because some people digested asparagus differently from others, so some excreted odorous urine after eating asparagus, and others did not. In the 1980s, three studies from France, China, and Israel published results showing that producing odorous urine from asparagus was a common human characteristic. The Israeli study found that from their 307 subjects, all of those who could smell "asparagus urine" could detect it in the urine of anyone who had eaten asparagus, even if the person who produced it could not detect it. A 2010 study found variations in both production of odorous urine and the ability to detect the odor, but that these were not tightly related. Most people are thought to produce the odorous compounds after eating asparagus, but the differing abilities of various individuals to detect the odor at increasing dilutions suggests a genetically determined specific sensitivity.
In 2010, the company 23andMe published a genome-wide association study on whether participants have "ever noticed a peculiar odor when you pee after eating asparagus?" This study pinpointed a single-nucleotide polymorphism (SNP) in a cluster of olfactory genes associated with the ability to detect the odor. While this SNP did not explain all of the difference in detection between people, it provides support for the theory that genetic differences occur in olfactory receptors that lead people to be unable to smell these odorous compounds.
Certain compounds in asparagus are metabolized to yield ammonia and various sulfur-containing degradation products, including various thiols and thioesters, which give urine a characteristic smell.
- dimethyl sulfide
- dimethyl disulfide
- dimethyl sulfoxide
- dimethyl sulfone
Subjectively, the first two are the most pungent, while the last two (sulfur-oxidized) give a sweet aroma. A mixture of these compounds form a "reconstituted asparagus urine" odor. This was first investigated in 1891 by Marceli Nencki, who attributed the smell to methanethiol. These compounds originate in the asparagus as asparagusic acid and its derivatives, as these are the only sulfur-containing compounds unique to asparagus. As these are more present in young asparagus, this accords with the observation that the smell is more pronounced after eating young asparagus. The biological mechanism for the production of these compounds is less clear.
The onset of the asparagus urine smell is remarkably rapid while the decline is slower. The smell has been reported to be detectable 15 to 30 minutes after ingestion and subsides with a half-life of approximately 4 hours.
Three types of asparagus are on display, with white asparagus at the back and green asparagus in the middle. The plant at the front is Ornithogalum pyrenaicum, commonly called wild asparagus, and sometimes "Bath asparagus".
- Latin velocius quam asparagi conquantur (or celerius quam asparagi cocuntur), ascribed to Augustus by Suetonius (The Lives of the Twelve Caesars, Book 2 (Augustus), para. 87). See List of Latin phrases (V).
- In the eleventh century AD the word "sparagus" appeared in an English text. See Brunning (June 2010), p. 6. – Brunning uses the term "in print", though no printing technique was used in England at the time. In the same sentence, she states that peasants often called it "sparrow grass", and further on mentions a 1667 diary in which Samuel Pepys bought a bundle of "sparrow grass" in Fenchurch Street, London.
- The Plant List, Asparagus officinalis L.
- "The French Chef; Asparagus From Tip to Butt". The Julia Child Project. WGBH Open Vault. 25 April 1966. Retrieved 16 September 2016.
- Plants of the World Online. (n.d.). "Asparagus officinalis L." Royal Botanic Gardens, Kew. Retrieved 31 May 2018.
- Flora Europaea. (n.d.). "Asparagus officinalis". Royal Botanic Garden Edinburgh. Retrieved 19 May 2010.
- Euro+Med Plantbase Project. "Asparagus officinalis". Botanic Garden and Botanical Museum Berlin-Dahlem. Archived from the original on 11 August 2011. Retrieved 19 May 2010.
- "Asparagus officinalis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 19 May 2010.
- Grubben, G.J.H.; Denton, O.A., eds. (2004). Plant Resources of Tropical Africa 2: Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen.
- Diderot, D. (2009) . "Asparagus". The Encyclopedia of Diderot & d'Alembert. Retrieved 1 April 2015 – via Collaborative Translation Project, University of Michigan.
- Garden Grow. (n.d.). "Growing Asparagus". Retrieved 19 November 2019.
- Blamey, M. & Grey-Wilson, C. (1989). Flora of Britain and Northern Europe. ISBN 0-340-40170-2.
- Stace, C. van der Meijden, R.; de Kort, I. (eds.). "Asparagus prostratus (Asparagus, Wild)". Interactive Flora of NW Europe. ETI BioInformatics. Archived from the original on 23 September 2009. Retrieved 19 May 2010.
- "Asparagus prostratus". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 19 May 2010.
- Brunning, Pam (June 2010). "Asparagus – Liliaceae–Asparagacease" (PDF). Food & Wine (103). Retrieved 26 August 2011.
- "Over asperge – Oudheid" (in Dutch). Stichting Afzetbevordering Asperges. Retrieved 26 August 2011.
- Vaughan, John Griffith; Geissler, Catherine Alison; Nicholson, Barbara (1997). The New Oxford Book of Food Plants. Oxford University Press.
- "Wit goud en koningin der groente: vorstelijke asperges" (in Dutch). Netherlands: Infoyo (web publisher). 20 May 2009. Archived from the original on 19 January 2012. Retrieved 26 August 2011.
- Blackburn, Roderic H.; Kelley, Nancy A. New World Dutch Studies: Dutch Arts and Culture in Colonial America, 1609-1776 : Proceedings of the Symposium. SUNY Press. ISBN 978-1-4384-2989-2.
- Murphy, Andrew R. (8 October 2018). William Penn: A Life. Oxford University Press. ISBN 978-0-19-023426-3.
- "Growing Asparagus in the Home Garden; Section on harvesting" (PDF). Purdue University Cooperative Extension Service. p. 2. Retrieved 31 January 2014.
- Snyder, Harry. (1908). "Human Foods and their Nutritive value". The MacMillan Company.
- "Nutrition Facts".
- USDA Agricultural Research Service Data section 11 (pg 61) Archived 13 January 2012 at the Wayback Machine
- Anderson, R A (October 1997). "Nutritional factors influencing the glucose/insulin system: chromium". Journal of the American College of Nutrition. 16 (5): 404–410. doi:10.1080/07315724.1997.10718705. ISSN 0731-5724. PMID 9322187.
- Randhawa, Jessica (1 July 2019). "The Forked Spoon". The Forked spoon. Retrieved 29 November 2019.
- Salad Recipe Archived 19 July 2010 at the Wayback Machine
- "Ingredients – Asparagus". DrGourmet.com. Retrieved 20 July 2011.
- Wolford, Ron; Banks, Drusilla. "Asparagus". Watch Your Garden Grow. University of Illinois Extension. Retrieved 3 May 2020.
- Oxford Times: "Time to glory in asparagus again". Archived 7 September 2009 at the Wayback Machine
- "Page Redirection".
- "Wit goud en koningin der groente: vorstelijke asperges" (in Dutch). Netherlands: Infoyo (web publisher). 20 May 2009. Archived from the original on 19 January 2012. Retrieved 26 August 2011.
- Jules Gouffé; Etienne Antoine; Eugène Ronjat (5 August 2016). ""Chapitre XVI Légumes 71.Légumes"". Le Livre de cuisine: Comprenant la cuisine de ménage et la grande cuisine, 1893 (in French). ISBN 9782346013760. Retrieved 28 April 2020. (Asperge is French for asparagus.)
- Evans, Stephen (21 April 2012). "Asparagus, royalty and the joys of seasonal eating". BBC News. Retrieved 22 April 2012.
- "Glossary – 'S'". BBC Food. Retrieved 8 June 2007.
- "New breed of early asparagus hits the shelves". The Daily Telegraph. 19 March 2011. Retrieved 20 March 2011.
- Raymond, Francine (21 May 2014). "Asparagus: this season's hottest shades to grow". The Telegraph. Retrieved 21 May 2017.
- "Introducing the latest superfood... Purple asparagus". Daily Mail. 26 April 2007. Retrieved 21 May 2017.
- "Plants for a Future".
- "Food and Agriculture Organisation Statistics (FAOSTAT)". Retrieved 8 September 2019.
- "Food and Agriculture Organisation Statistics (FAOSTAT)". Archived from the original on 7 November 2007. Retrieved 11 November 2007.
- USDA (January 2006). Vegetables 2005 Summary. National Agricultural Statistics Service.
- Spence, Molly. "Asparagus: The King of Vegetables". German Agricultural Marketing Board. Archived from the original (DOC) on 13 October 2007. Retrieved 26 February 2007.
- Hart, Carolyn (5 September 2015). "Asparagus in autumn? Meet the man behind its extended season". Retrieved 3 January 2019.
- "U.K. grower creates asparagus market – Vegetable Growers News". Vegetable Growers News.
- Bhowmik, Pankaj Kumar; Matsui, Toshiyuki; Ikeuchi, Takao; Suzuki, Haruo (November 2002). "Changes in storage quality and shelf life of green asparagus over an extended harvest season". Postharvest Biology and Technology. 26 (3): 323–328. doi:10.1016/S0925-5214(02)00062-5.
- "About the Festival". British Aparagus Festival. British Asparagus Festival. Retrieved 26 March 2019.
- Davis, William A. (14 May 2008). "Buried treasure: white asparagus". The Christian Science Monitor. Schwetzingen, Germany. Retrieved 26 March 2019.
- Walker, John (1806). A Critical Pronouncing Dictionary, and Expositor of the English Language. Retrieved 18 November 2016.
- Ewart Evans, George "Ask the Fellows who Cut the Hay"
- "How to consume asparagus" (in Turkish). 1organik.com. Retrieved 21 May 2017.
- McGee, Harold (2004). "6". McGee on Food and Cooking. Hodder and Stoughton. p. 315. ISBN 978-0-340-83149-6.
- Arbuthnot J (1735). An Essay Concerning the Nature of Aliments (3rd ed.). London: J. Tonson. pp. 64261–262.
- Franklin, Benjamin (c. 1781). "Letter to the Royal Academy of Brussels". Archived from the original on 15 December 2012.
- From the French "[...] changer mon pot de chambre en un vase de parfum", Du côté de chez Swann, Gallimard, 1988.
- Stromberg, Joseph. "Why Asparagus Makes Your Urine Smell". smithsonianmag.com.
- C. RICHER; N. DECKER; J. BELIN; J. L. IMBS; J. L. MONTASTRUC; J. F. GIUDICELLI (May 1989). "Odorous urine in man after asparagus". Br. J. Clin. Pharmacol. 27 (5): 640–1. doi:10.1111/j.1365-2125.1989.tb03431.x. PMC 1379934. PMID 2757887.
- S. C. MITCHELL (May 1989). "Asparagus and malodorous urine". Br. J. Clin. Pharmacol. 27 (5): 641–2. doi:10.1111/j.1365-2125.1989.tb03432.x. PMC 1379935. PMID 2757888.
- Pelchat, M. L.; Bykowski, C.; Duke, F. F.; Reed, D. R. (2010). "Excretion and Perception of a Characteristic Odor in Urine after Asparagus Ingestion: a Psychophysical and Genetic Study". Chemical Senses. 36 (1): 9–17. doi:10.1093/chemse/bjq081. PMC 3002398. PMID 20876394.
- "The scientific chef: asparagus pee". The Guardian. 23 September 2005. Archived from the original on 4 May 2007. Retrieved 21 April 2007.
- Hannah Holmes. "Why Asparagus Makes Your Pee Stink". Discover.com. Archived from the original on 29 February 2008.
- Lison M, Blondheim SH, Melmed RN (1980). "A polymorphism of the ability to smell urinary metabolites of asparagus". Br Med J. 281 (6256): 1676–8. doi:10.1136/bmj.281.6256.1676. PMC 1715705. PMID 7448566.
- Eriksson N, Macpherson JM, Tung JY, Hon LS, Naughton B, Saxonov S, Avey L, Wojcicki A, Pe'er I, Mountain J (2010). Gibson G (ed.). "Web-Based, Participant-Driven Studies Yield Novel Genetic Associations for Common Traits". PLOS Genet. 6 (6): e1000993. doi:10.1371/journal.pgen.1000993. PMC 2891811. PMID 20585627.
- White RH. (1975). "Occurrence of S-methyl thioesters in urines of humans after they have eaten asparagus". Science. 189 (4205): 810–11. Bibcode:1975Sci...189..810W. doi:10.1126/science.1162354. PMID 1162354.
- Pelchat, M. L.; Bykowski, C.; Duke, F. F.; Reed, D. R. (26 July 2010). "Excretion and Perception of a Characteristic Odor in Urine after Asparagus Ingestion: a Psychophysical and Genetic Study". Chemical Senses. 36 (1): 9–17. doi:10.1093/chemse/bjq081. PMC 3002398. PMID 20876394.
- Waring RH, Mitchell SC, Fenwick GR (1987). "The chemical nature of the urinary odour produced by man after asparagus ingestion". Xenobiotica. 17 (11): 1363–1371. doi:10.3109/00498258709047166. PMID 3433805.
- Mitchell S.C. (2001). "Food idiosyncrasies: beetroot and asparagus". Drug Metabolism and Disposition. 29 (4): 539–543. PMID 11259347.
- Nencki, Marceli (1891). "Ueber das vorkommen von methylmercaptan im menschlichen harn nach spargelgenuss". Arch. Exp. Pathol. Pharmakol. 28 (3–4): 206–209. doi:10.1007/BF01824333.
- Somer, E. (14 August 2000). "Eau D'Asparagus". WebMD. Archived from the original on 21 August 2006. Retrieved 31 August 2006.
- Research completed and verified by Dr. R. McLellan from the University of Waterloo.
- van Hasselt, J. G. Coen; Elassaiss-Schaap, Jeroen; Ramamoorthy, Anuradha; Sadler, Brian M.; Kasichayanula, Sreeneeranj; Edwards, Yin; van der Graaf, Piet H.; Zhang, Lei; Wagner, John A. "The proof is in the pee: Population asparagus urinary odor kinetics". PAGE. Abstracts of the Annual Meeting of the Population Approach Group in Europe. 25. Retrieved 7 July 2016.
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- Kew Species Profile: Asparagus officinalis (garden asparagus)
- PROTAbase on Asparagus officinalis
- Asparagus officinalis – Plants for a Future database entry
- "World Asparagus Situation and Outlook" (PDF). Archived from the original (PDF) on 18 October 2012. (55.0 KB) – 2005 USDA report
- Asparagus Production Management and Marketing at the Library of Congress Web Archives (archived 17 September 2002) – commercial growing (OSU bulletin)