Asparagus

Bushy plants in early September

Asparagus is a low upkeep perennial that will produce for 25+ years without replanting.  Once established, the asparagus bed will produce up to 2 pounds of asparagus per square foot every year.  With fresh asparagus being relatively expensive, the investment will pay for itself quickly.

Thin first shoots in mid June

Asparagus likes a rich, well drained soil.  They do very poorly in constantly wet soil.  This makes a compost-filled raised bed nearly ideal.  When planning for your bed, determine how many times a week through the year that you would like to dine on asparagus.  Go to the store and purchase some to get an idea of how much asparagus each meal requires and how many pounds of asparagus you want to grow each year.  In a sunny location, build a raised bed that is approximately 1 square foot for each pound of asparagus desired (example a 4'x8' bed will produce at least 32 pounds per year).  This bed should be 8" deep and no wider than 4' to allow picking without walking on and compacting the soil.  Our customer's bed (pictured) is 2' wide because it is against the house and accessible only from one side.

In late winter, order asparagus crowns to be delivered in early spring (April in Northwest Arkansas).  The number or crowns ordered depends on how quickly you want the bed to reach maximum production.  At a minimum, order one crown per square foot.  For quicker maximum production, plan on four crowns per square foot (do not exceed 4).  There is also the choice of one year old or two year old crowns.  Again, two year old crowns will reach maximum production more quickly than one year olds.  Determine what balance of cost and time until maximum production is the right balance for you.  Our customer wanted maximum production as soon as possible, so we planted 2 year old crowns, 4 per square foot.  As you can see, they took off like gangbusters.  When the crowns arrive, fill the bed with a 1-2" layer of compost.  Arrange the crowns as desired in the bed, while spreading the roots out horizontally as much as possible.  Now, cover them with 5-6" of well finished compost.  After planting the crowns, water the bed as necessary to maintain the soil moisture as damp as a well wrung out sponge.  Small, spindly shoots should begin emerging in the ensuing weeks.  Do not harvest them.  For the first year, the crowns need to gather energy from the sun to establish themselves and to make it through the winter.  The next season, when spears are the thickness of a pencil, you may begin harvesting.  When the diameter of 75% of the spears become too small to harvest, stop harvesting for the year.  In the first year or two of harvest, you may have a shortened harvest season.  When fully established, the bed will produce for up to 8 weeks.

Harvest by snapping the spears off by hand.  When harvesting, take every spear available.  Do not allow any spears to begin to open up until you have determined that harvesting is done for the year (when 75% of spears are smaller than a pencil).  Once harvesting is over, the plants will grow fern like stalks up to 5 feet tall.  Do not trim these.  More greenery = more photosynthesis = more and bigger spears for you.  Leave the dead stalks in place all winter to insulate the bed and retain moisture.  In early Spring, trim the old stalks close to the ground and remove them.  Apply an inch of well broken down compost.  When the spears begin to emerge, harvest as described above.

Tips and Tricks:

• Build the bed from materials that will last as long as the asparagus, such as stone, masonry block, thick metal, concrete, etc.  Avoid wood.
• Purchase an all-male hybrid variety.  They produce three times as many spears as older varieties and do not produce seed, which produce a weedy mess.  
• Place a thick layer of cardboard in the bottom of the empty bed to serve as a weed barrier.
• Asparagus grows very thick later in the summer, which reduces air flow through the bed.  This lack of air flow can keep the interior from drying out, increasing the odds of fungal issues.  To reduce this, we prefer to bury a soaker hose 1/2" below the surface to allow us to water in a way to reduce moisture on the greenery.  Fortunately, our customer has not experienced any fungal issues thus far.  

Putting up the Harvest:

• Freezing
• To avoid mushy asparagus, we want it  to freeze as quickly as possible.  This makes smaller ice crystals, which means less cell damage
• Turn your freezer to its coldest setting and place a cookie sheet in there the night before
• Wash and trim freshly picked asparagus as desired
• Blanch by plunging into boiling water for 3 minutes 
• Quickly, plunge asparagus into ice water and leave it there until thoroughly chilled inside
• Pat dry and place on a cold cookie sheet (straight from the freezer) in a single layer
• Place in your freezer in the coldest location
• For forced air freezers, this is in the path of the cold air coming from the vent
• For chest and still air freezers, this is the lowest spot available
• Put in airtight freezer bags with as much air removed as possible
• Canning
• Aparagus cans up to a texture very similar to green beans
• Consult a quality canning manual, such as the Ball Blue Book
• Dehydrating (best for use as a recipe addition such as in soups)
• Wash, blanch, and ice as described above
• Pat dry and dry in your dehydrator at its lowest temperature setting over night or until hard as a rock