April Harvest of the Month: Asparagus

Asparagus greets us every spring but requires a bit of patience if you wish to receive the benefits of its harvest. In fact, it takes two to three years for this bulb and stem species to produce the delicately flavored stalks we enjoy so much.  BUT, If you are patient, this plant can be productive for up to 20 years (Old Farmers Almanac).

Copyright ©2013 MDidea.com

Copyright ©2013 MDidea.com

History

Asparagus has been a delicacy since ancient times and has a long history of use in India and Asia as a botanical medicine.  The vegetable has been largely exalted for the saponins in its root system. Studies have shown that saponins have anti-inflammatory and anti-cancer properties. Intake of saponins is also related to improved blood pressure, improved blood sugar regulation and better control of fat levels.

Did you know? Asparagus has a much faster respiration rate than many other vegetables, which means that is will lose water, wrinkle and harden faster than most vegetables.  In fact, like all vegetables, asparagus doesn’t instantly “die” when it is picked. Instead, it continues to perform metabolic activities [termed the respiration rate] such as taking in oxygen, breaking down starches and sugars and releasing carbon dioxide (Old Farmers Almanac). For a frame of reference, the respiration rate of asparagus is 5x greater than the rate for onions and potatoes; 3x greater than the rate for lettuce and tomato; and twice as fast as the rate for cauliflower and avocado [1]. Due to this fast respiration rate, it is important to wrap the ends of the stalks with a damp towel and refrigerate or freeze the asparagus.

Fun fact: the Romans used to store their asparagus in the Alps during the winter.

Asparagus reached America in the Colonial times and was a particular favorite of Thomas Jefferson.  He grew asparagus in his garden at Monticello and preferred a common centuries-old french preparation of the vegetable.  Jefferson first enjoyed this dish while he was Minister to France and even had an enslaved french-trained chef at his home in Monticello, who [most likely] prepared this dish for him and his American guests.

Thomas Jeffeson's Marinated Asparagus

Click here for Thomas Jefferson’s Marinated Asparagus recipe. photo credit: The City Tavern Cookbook

This recipe originates from The City Tavern Cookbook, a compilation of historical recipes collected by Walter Staib, the executive chef at The City Tavern Restaurant in Philadelphia.

How to Grow Asparagus

Asparagus should be planted in the early spring, as soon as the soil can be worked. The crowns [which is the root system of a one year-old plant] should be planted in a place with good drainage in full sun.

Diagram of asparagus

Diagram of asparagus, photo credit: cottageatthecrossroads.com

Click here to get a more in-depth description of how to plant your asparagus!

Asparagus is a useful companion plant for tomatoes and parsley. The tomato plant repels the asparagus beetle while the asparagus repels harmful root nematodes.

Asparagus also tends to thrive when planted with dill, coriander, basil, comfrey and marigolds.

Fun Fact: when coupled with basil, asparagus encourages frequent visits from ladybugs.

Also – did you know that white asparagus is not a different species of asparagus but is the result of a growing technique? This type of asparagus is very popular in the Netherlands, Spain, France, Poland, Belgium, Germany Austria, Italy and Switzerland. Compared to green asparagus, white asparagus is less bitter and much more tender [however it does have less fiber], and is often called “white gold”, “edible ivory” and “the royal vegetable”. To grow white asparagus, you simply cover the shoots with soil as they grow. This technique is called “earthed up”. Without exposure to sunlight, the plant produces no chlorophyll, stunting the production of green pigment.

Purple asparagus – this kind of asparagus is bred to be purple, but it turns green when it is cooked. Purple varieties tend to have thicker but fewer spears and are sweeter and tenderer.

Fun Fact: A pinch of baking soda in the cooking water keeps beans, spinach and asparagus greener.

Nutrition Facts

Asparagus is low in calories and very low in sodium. This hearty spring vegetable also has trace amounts of the mineral chromium, which enhances the ability of insulin to transport glucose from the bloodstream into cells . Asparagus is also rich with amino acids.

.Asparagus_Traceelements

How to prepare

Only young asparagus shoots are commonly eaten.  Once the buds start to open, which is also called “ferning out,” the shoots quickly turn woody.

There are a number of ways to prepare asparagus. It can be stir-fried, quickly grilled over charcoal or hardwood embers, used in stews and soups or even eaten raw, as a component of a salad. Asparagus can also be pickled and stored for several years.  In Colonial times, asparagus was typically boiled or marinated till tender, much like Jefferson’s dish mentioned above.  George Washington also favored asparagus, particularly served as a ragoût.  He not only grew asparagus at Mount Vernon, much like Jefferson, but was also known to serve his favorite dishes to his guests.

Mount Vernon gardens

Mount Vernon gardens

For another common asparagus recipe, see the excerpt below from the 1842 Virginia Housewife cookbook, by Mary Randolph,

“Set a stew-pan with plenty of water on the fire, sprinkle a handful of salt in it, let it boil, and skim it; then put in the asparagus prepared thus: scrape all the stalks till they are perfectly clean; throw them into a pan of cold water and you scrape them; when they are all done, tie them in little bundles, of a quarter of a hundred each, with bass, if you can get it, or tape; cut off the stalks at the bottom, that they may be all of a length; when they are tender at the stalk, which will be in from twenty to thirty minutes, they are done enough…While the asparagus is boiling toast a slice of a loaf of bread, about a half an inch thick; brown it delicately on both sides; dip it lightly in the liquor the asparagus was boiled in, and lay it in the middle of a dish; pour some melted butter on the toast, and lay the asparagus upon it; let it project beyond the asparagus, that the company may see there is a toast. Do not pour butter over them, but send some in a boat.” [2]

The Food Heritage Project thanks you for taking the time to read about the history and heritage of asparagus and asks you to consider eating fresh asparagus this spring!

   This blog was posted as part of City Schoolyard Garden‘s Harvest of the Month program.

This post was written by Abigail Sandberg

References:

1. Nassef, Dalia; El-Gaid, M.A. Abd (2012). “Evaluation of yield and its components of intercropped tomato – garlic in New Valley Governorate”Research Journal of Agriculture and Biological Sciences 8 (2): 256–260

2. Mary Randolph, The Virginia Housewife, Published by E.H. Butler & Co., 1860, Philadelphia. page 100.

3. Jefferson, Thomas. Garden Book, 1766-1824 [electronic edition]. Thomas Jefferson Papers: An Electronic Archive. Boston, Mass.: Massachusetts Historical Society, 2003.http://www.masshist.org/thomasjeffersonpapers/garden/.

4. Hatch, Peter. “Thomas Jefferson’s Favorite Vegetables.” Twinleaf Journal Online, 2000. Available on Monticello’s website: http://www.monticello.org/site/house-and-gardens/thomas-jeffersons-favorite-vegetables.

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