Wednesday, 17 September 2014 02:29

How does asparagus grow?

Find out why your urine smells after eating asparagus!!

 

 

  • Latin Name:

    Asparagus oficinalus

  • Growth:

    USDA Hardiness Zones 4 - 9

    Asparagus is a herbaceous plant and one of the few perennial vegetables that grows in North America, meaning that it is a vegetable crop that needs to be planted only once, but is harvested year after year. A well-maintained asparagus plant may continue producing edibles for up to twenty years.

     

    Asparagus thrives in all zones in North America, except for the warmest zones with climates higher than USDA Hardiness Zone 9. It grows best in sunny areas in well-drained soil. Without full sun exposure, the plant is too weak to produce robust stalks for consumption. Asparagus should be planted in soil with a pH level between 6 and 7. 

    Asparagus shoots, which emerge in spring, are what we think of as the asparagus spears we eat. They remain shoots for only a few days at which time they need to be harvested.  At this point, they are 6 to 8 inches in height and the end of the spear is tightly closed. Then they quickly mature into feathery, fern-like clouds that grow up to 5’ tall and 3’ wide. Full maturation must occur annually so the ferns can transfer energy to the roots for good spear development the following season. For this reason, it is important to leave some asparagus stalks in the crop during each spring harvest.

    Why does asparagus make your pee smell?

    Asparagus contains mercaptan, a sulphurous compound also found in rotten eggs, onions and garlic.  When mercaptan is broken down by your digestive system, it releases by-products that cause the strange odor.  This happens so quickly that your urine can develop the smell within 15 to 30 minutes of eating asparagus.

     

  • Propagation:

    Asparagus may be grown from seed, but will take up to three years to begin producing stalks. Asparagus crown division is a more common process, due to its higher success rate and more timely yield.

  • Harvest:

    Spears are harvested in spring when the plant’s edible new shoots are approximately 6 to 8 inches tall, with tips that are still firm and tight.  If the spear has begun to open and produce foliage, it will be too tough to eat and should be left to mature in the field. Spears harvested from young plants should be at least the diameter of a pencil. Older plants produce spears that are finger-width.

    To harvest asparagus, the spears are cut just below the soil line. Care is taken not to slice the crown or the younger, developing shoots that have yet to poke through the soil. Some commercial growers use mechanized harvesters that are designed especially to harvest asparagus. 

  • Storage:

    Fresh asparagus can be stored for approximately one week in the refrigerator. The stalks are washed and patted dry with a paper towel. They can be bound with a rubber band or string, bagged or wrapped, and stored in the refrigerator’s vegetable crisper. 

    Asparagus can be frozen for longer storage time. To do so, wash and then submerge the spears in boiling water for 3 to 5 minutes. They are then doused in cold water, dried and packaged in airtight containers or Ziploc bags. Asparagus can kept in the freezer for 8 to 12 months. 

  • History:

    Asparagus is native to the regions throughout Europe, the Mediterranean and Asia Minor. Its record of cultivation extends thousands of years throughout western Asia, northern Africa and most of Europe. Historians believe that the ancient Egyptians may have been among the first people to cultivate asparagus, as its image appears in friezes dating back as far as 3000 BCE. 

    Asparagus’ name is derived from the Greek word, asparagos, which means “sprout” or “shoot.” Although the vegetable borrows its name from the Greek language, it was the ancient Romans who produced the first literature about the cultivation of asparagus. 

    Under Roman farming practices, asparagus became the first frozen food item in history. The Romans ate asparagus when it was fresh in season, but they also brought it high into the Alps to freeze for later consumption and commercial purposes, and Emperor Augustus developed the “Asparagus Fleet” used specifically to transport the vegetable throughout the Roman empire.  Augustus also coined the Roman phrase, velocius quam asparagi conquantur, which means “faster than cooking asparagus,” for quick action.

    Galen, a prominent Greek physician during the Roman empire, hailed asparagus for its “cleansing and healing” benefits. Apicius, a collection of Roman cooking recipes dating to the 4th century AD, contains recipes that call for asparagus. Apicius is the oldest surviving history book in the history of civilization. 

    After the fall of the Roman empire, asparagus received little attention throughout the Middle Ages. However, in the 16th century, asparagus had a resurgence of popularity in England and France, where King Louis dubbed it “the king of vegetables” and had special greenhouses built so that he could enjoy asparagus year-round. Today, asparagus remains popular, and is cultivated throughout the world.

  • Top Producers:

    China is the world’s top producer of asparagus, followed by Peru, Germany,  the United States. and Mexico (FAOSTAT, 2010).

  • Varieties:

    Although green asparagus is most commonly grown, white and purple asparagus is also available. White asparagus is grown in the dark, shielded from sunlight during the growing process to prevent photosynthesis and the production of chlorophyll, keeping the plant white, more tender and sweet.

  • Products:

    Uses:

    Asparagus is primarily used for culinary purposes. It can be eaten raw or cooked, and is widely used in salads, pastas, and as a side dish.

  • Top Health Benefits:

    Asparagus is an alkaline food that is low in calories and carbohydrates, but rich in protein. It contains a variety of antioxidants, including vitamins C, A, E, K and traces of vitamin B complex, minerals including zinc, manganese, selenium, calcium and magnesium, and is a good source of dietary fiber. 

    Asparagus is also a rich source of the antioxidant, glutathione (GSH), which contains three amino acids combined into one molecule. GSH helps the body break down the carcinogens and free radicals that cause conditions such as cancer and heart disease.

    Asparagus contains a unique combination of anti-inflammatory nutrients. Among these are saponins, including  asparanin A, sarsasapogenin, protodioscin and diosgenin. In recent research, sarasapogenin, in particular, has become an anti-inflammatory compound of interest in its relation to the disease, amyotrophic lateral sclerosis (ALS; Lou Gehrig’s Disease). Because excessive inflammation may be a cause of death for certain nerve cells in ALS, asparagus’ anti-inflammatory components could play a preventative role. 

    The combination of antioxidants and anti-inflammatory components found in asparagus contribute to the prevention of conditions such as type II diabetes, heart disease, cancer, arthritis, and Alzheimer’s disease. 

    Asparagus contains significant levels of the nutrient, inulin, which is a unique type of carbohydrate called a polyfructan, or a “prebiotic.” Rather than being broken down in the first segments of the digestive tract like most carbohydrates, inulin passes undigested all the way to the large intestine, where it becomes an attractive food source for bacteria associated with lower risk of colon cancer, lower allergy risk, and better nutrient absorption. 

    Asparagus is also rich in fiber and protein, which work together to promote digestive health by keeping food moving through the digestive tract at the proper rate. 

    Asparagus provides approximately 3 grams of fiber per cup, including one gram of soluble fiber. Research has shown that repeated intake of soluble fiber is effective in lowering the risk of heart disease and type II diabetes. 

    The high vitamin B content in asparagus makes it a powerful vegetable for regulating the metabolism of sugars and starches, which relates to healthy blood sugar management. 

  • Grow it yourself:

    How to grow asparagus yourself

    From seed:

    1. If you have an asparagus plant available, collect the red berries from a mature fern at the end of the season, before the first frost, as seeds will only be viable if they have not been frozen.
    2. Crush the berries to separate the seeds and soak them to remove the rest of the pulp.
    3. Allow the seeds to dry out for a few days, then store in a cool, dry location until ready to plant. 
    4. Start seeds indoors and transplant to a garden in spring, after the danger of frost has passed.
    5. An asparagus plant grown from seed will require two to three years to mature before it is ready for harvest.

    By crown division:

    1. Look for fresh roots with firm flesh. Roots that are withered or papery may be too old to produce healthy new stalks. 
    2. Choose a healthy parent plant and dig up the root crown in late fall, after the last of the ferns have yellowed and died off. Cut the crown into several pieces, making sure to leave plenty of healthy root attached to each piece. 
    3. Asparagus crowns must be planted when they are dormant. This means the crowns can be planted immediately.  They can also be stored (in a cool, dry place in a mesh or paper bag filled with sawdust) to be planted later, in early spring, when the ground is workable between frosts. As long as there is at least 2 inches of soil covering the crowns, they will tolerate a frost.
    4. Plant crowns in a bed that receives at least eight hours of full sunlight, spaced 15 to 18 inches apart, in rows spaced 5’ apart. Use well-draining soil with a pH balance between 6 and 7, amending with nutrient-rich fertilizer as necessary. The optimal depth to plant root crowns is 6 to 8 inches, as shallower planting produces weak spears, and deeper planting produces thicker, but significantly fewer, spears.
    5. Allow the spears to grow through spring and summer, watering the plant regularly--but be careful not to overwater. In fall, the spears will mature into cloud-like fern spreads. Once this foliage has died off, remove to discourage pests. After fronds have been cut back in fall, top dress with a layer of mulch or compost. Do this annually.
    6. An asparagus plant propagated from root crown must go through one full growth cycle before it will begin to produce edible stalks. Optimally, the plant will be allowed two full growing seasons to feed itself and grow strong before it is harvested. 

    This may seem like a lengthy time investment before yielding an edible crop, but an asparagus plant that is cared for properly in its early stages will thrive and produce edibles for fifteen years or more.