What is Asparagus?
Also known as garden asparagus or sparrow grass, asparagus is a flowering perennial plant and a spring vegetable. Known scientifically as Asparagus officinalis, the asparagus plant belongs to the Asparagus genus.
Just like garlic and onions, Allium species, the asparagus plant was classified under the lily family (Liliaceae). However, it was split with asparagus under the Asparagaceae family while plants that look like onions fall under the Amaryllidaceae family.
Believed to be native to northern Africa, many parts of Europe and western sides of Asia, asparagus is widely grown as a vegetable crop for its nutritious benefits. The word asparagus was obtained from a Latin word 'sparagus', English word 'sperage', Greek word 'asparagos' or 'aspharagos' and the Persian word 'asparag'.
The word asparagus means 'shoot' or 'sprout'. This can be identified with the fact that only the plant's shoots or sprouts are eaten. Although there are over 300 asparagus species, only 20 are edible.
The Biology of the Asparagus Plant
Typical of feathery foliage and stout stems, asparagus is a herbaceous plant that grows to a height of 100cm to 150cm. The perennial plant has a stem with cladodes (needle-like leaves) acting as scale leaves. The leaves grow to a length of up to 32mm and breadth of 1mm.
The needle-like leaves are clustered in a group of 4 to 15 and grow in the shape of roses. The asparagus plant has fasciculated types of roots with adventitious properties. Asparagus flowers are yellowish to green-white, in addition to being shaped like a bell.
The flowers grow up to 6.5mm in length, with a minimum of 6 petals. They're produced in 2 or 3 clusters or singly at points where the leaves or branches join the main plant. The female and male flowers of this plant are dioecious, and sometimes even hermaphrodites.
It yields small, red berry fruits that grow up to 10mm in diameter. However, they're poisonous for human consumption. Prostratus (Dumort) Corb., subspecies of asparagus officinalis, are native to the European western coasts, including northern Ireland and northern Spain, northwest Germany and the Great Britain.
The plant's slow-growing prostrate stems can attain up to 70cm in height while shorter needle-like leaves grow up to 18mm in length.
The History and Origin of the Asparagus Plant
Asparagus has diuretic properties and a delicate flavor, hence has been used for its medicinal value and as a vegetable for many years, about 2000 years ago. Spain and Syria are some early users of the asparagus plant. The Egyptian frieze that's believed to date back to 3000BC features the plant as an offering, indicating its ancient use.
The Roman and Greeks used the plant as a vegetable; it was eaten fresh during the growing season and dried or frozen in the Alps Mountains to preserve the plant for later use in the Epicurus Feast. The Roman Emperor Augustus developed a vegetable-hauling machine that was known as the 'Asparagus Fleet'.
The hauling machine was deemed faster than the process of cooking the asparagus plant. The De re coquinaria version 3, the oldest recipe book written in the 3rd Century AD by Apicius, features an asparagus recipe for cooking the vegetable.
Although asparagus did not draw so much attention during the Medieval era, the plant was mentioned by Galen, a prominent ancient Greek physician, during the 2nd Century AD as a herb that's beneficial. Similarly, Ananga Ranga, an Indian, claimed that the plant can fight fatigue due to its high phosphorous content.
'The Perfumed Garden,' a piece written by al-Nafzawi, praises asparagus for its aphrodisiacal power. The plant was first noticed in 1538 in England and in 1542 in Germany. However, French monasteries began growing asparagus much earlier in 1469. The tips of the asparagus plant has the most delicate and strongest flavor, and the finest texture.
Uses of the Asparagus Plant
Asparagus can be grilled, used as a vegetable or an appetizer or stir-fried. It can also be used to prepare vegetable soups or as an ingredient in certain stews. The plant can also be pickled for storage or marinated.
It's also eaten raw in salads and can be steamed or boiled. Asparagus is peeled for faster poaching. Only young shoots or buds of the plant are often cooked or eaten raw.
Nutritional Content of Asparagus
Asparagus has a high nutritional value. It is rich in vitamins (A, B1, B2, B3, B5, B6, C, E and K), minerals and essential proteins. Apart from folates, niacin, riboflavin and thiamine, the vegetable contains calcium, iron, manganese, magnesium, potassium, phosphorous, zinc and selenium.
It is low in sodium and calories with no cholesterol content. Asparagus plant is also rich in dietary fiber. According to the United States Department of Agriculture National Nutrient Database, a cup containing 134 grams of asparagus has 27 calories and 2.8g of dietary fiber.
Health Benefits of Asparagus
Asparagus reduces the risk of low birth weight in pregnancy due to its folate content. It eases premenstrual cramps, maintains homocysteine levels, improves digestion and fertility, controls diabetes, fights tumors, treats rheumatism and improves vision for better eye care.
It also relieves depression and cures epilepsy and treats neurodegenerative diseases and tuberculosis. Asparagus has anti-inflammatory properties, maintains the right cholesterol levels in blood and treats urinary tract infections, among other health benefits.
White Asparagus in Europe
Also known locally as 'edible ivory', 'white gold' or 'the royal vegetable', white asparagus is popular in Germany, Netherlands, Austria, Spain, Switzerland, Italy, France, Belgium and Poland. The shoots of green asparagus plants are earthed up (covered in soil) during growth to prevent sunlight exposure and thus no photosynthesis.
The resulting plant shoots, the edible parts, remain white. White asparagus is believed to be fresh, more tender and tastier. Turkey also cultivates white asparagus.
Cultivation of Asparagus
Asparagus thrives in saline soils. Traditionally, salt was mixed with soil intended for planting asparagus to suppress weeds. Asparagus crowns are planted in winter and in spring, budding begins. Sprue asparagus are the first plant 'thinnings' to be picked after the shoots appear and grow in spring.
An early season asparagus in the UK grows at 7 0C and matures two months earlier than the normal variety that thrives at 9 0C. 'Violetto d' Albenga' is a purple asparagus variety native to Albenga, a city in Italy. The 'Pacific Purple' variety resulted from breeding work going on in New Zealand and the U.S.
Unlike white and green asparagus varieties, the purple variety has low fiber content and is rich in sugar.
Asparagus as a Tomato Companion Plant
Asparagus can be inter-planted with tomatoes as a companion plant because it can repel tomato root nematodes. On the other hand, tomatoes repel asparagus beetle, creating a symbiotic relationship.
Large-Scale Asparagus Production
China, France, Mexico, the U.S and Germany are the top asparagus producers worldwide, in that order, according to 2013 statistics. China produced 7 million tonnes while Germany only 57,000 tonnes in that year.
California, Germany and Northern Europe hold asparagus festivals annually.
Asparagus in Urine
When asparagus is eaten and digested, the asparagusic acid in it is broken down into compounds that contain sulfur, leading to a powerful odor in urine. The plant can also causes gases when eaten.
Asparagus Recipes to Try
Grow Asparagus at Home
You can grow asparagus plants at home either indoors or outdoors in a raised bed or pot to enjoy their various health benefits through delicacies of your choice.
Browse our collection of gardening tools and supplies to order what you need to grow asparagus plants at home.