The most common type of asparagus and, like most plants, the colour is the result of chlorophyll produced during photosynthesis.
Sweeter than green asparagus but turns green when cooked.
Is actually green asparagus grown without light in a technique called blanching. The spears are covered in mounds of dirt as they’re growing and therefor don’t receive any light. No photosynthesize takes place so they don’t build up chlorophyll which provides the green colour. This process is popular in Europe and creates a more delicate, earthy taste than traditional green asparagus.
How to Buy:
Asparagus is often bundled and positioned upright with the end of the plant in water. This helps absorb moisture up to the top of the plant and keeps it plump. Look for straight, firm spears with smooth skin, even colour and tight, darker-coloured heads. Crispness is more important than size when buying asparagus, so avoid droopy or soft stemmed bundles. Also make sure the heads or ‘flowers’ on the stems are not slimy or moist.
How to Store:
If you’re going to use the asparagus within a day or two, simply wrap the bottom ends with a wet paper towel and store in the refrigerator.
To keep asparagus fresh for a week or even two, trim off approximately 2 cm from the ends, stand the asparagus in a jar or other tall container filled with 1 inch (2.5 cm) of water, cover the tops loosely with plastic and store in the refrigerator.
Frozen asparagus can last for eight to twelve months but may become mushy when thawed so choose your preparations carefully. You can reduce the chances of mushy asparagus by choosing thicker spears and processing them quickly.
First, sort the spears according to size then blanch in boiling water. Large spears will take 4 minutes, medium spears 3 minutes and small spears 2 minutes. Take them out of the boiling water and immediately immerse in cold water. Quickly blot spears dry then spread in a single layer on a parchment lined cookie sheet before placing in the freezer for four to six hours. Once frozen, transfer to a freezer bag. If you aren’t processing many, you can skip the cookie sheet and lay the blanched spears in a single layer in a sealable freezer bag and place them as flatly as possible into the freezer. Remember to remove as much air as possible from the bag.
You may skip the blanching process and quick-freeze spears by spreading them on a cookie sheet and placing them in the freeze prior to placing them in a sealable freezer bag.
How to Prepare:
Asparagus is a very versatile vegetable and can be sauteed or roasted as a side dish, added to pasta or made the star of a delicious soup or frittata. Before using, snap or cut off the bottom end of the asparagus as it will be woody and tough.
Asparagus is very low in sodium and low in calories (~4 calories per spear). It is a good source of dietary fibre and Vitamins A and C.
Asparagus is a diuretic. It brings about an increase in the excretion of chlorine and phosphate compounds. This dilutes the urine, which helps prevent renal and urinary tract inflammations. The ‘stinky pee’ phenomenon some people experience after eating asparagus is the result of sulfurous amino acids in the spears that are released during digestion. However, only about 25% of the population has the gene that makes them able to smell the amino acids.
Asparagus is rich in rutin, a powerful antioxidant which may help thin blood, improve circulation, inhibit blood clots and act as an anti-inflammatory.
How They Are Grown:
The majority of Canadian asparagus is grown in fields in Norfolk County, Ontario with some minor production in Quebec and British Columbia. As a perennial, asparagus fields aren’t cultivated at the end of the harvest, which happens in the spring. It can take up to 5 years for an asparagus fern to produce a reliable crop and a healthy fern will produce for up to 20 years.
A single fern will produce around 14 spears per season and a spear can grow 6 inches in one day so the plants are harvested multiple times over the course of 8 weeks. Asparagus is hand picked when it is the ideal length of at least 10 inches (25 cm) by workers with specially designed cutting tools. This is done during early mornings or during cooler hours in the evening to maximize freshness.
It is gathered in crates and sent to a packing facility where it is washed and graded based on thickness, length and quality of the head. Asparagus will continue maturing after it’s picked so it is quickly cooled to remove any heat left from the field. The extra length of the woody stem is cut off so the spears are relatively the same size for packaging 10 inches (25 cm). Asparagus is bundled in 1 lb (500 g) bunches or loose packed in boxes and shipped on refrigerated trucks to the grocery store where it arrives within two to three days of harvesting.
After harvest, the remaining spears are left to grow to full size ferns 5 to 8 feet (1.5 – 2.5 m high). This helps store nutrients in the roots that will be used to produce new growth for the next year.
Canadian Crop is Available: April to Late June
Grown in: Ontario, BC and Quebec
For More Information:
- Asparagus Farmers of Ontario
- BC Vegetable Marketing Commission
- BC Ag in the Classroom – Asparagus Fact sheet
- Ontario Fruit and Vegetable Growers Association
- Quebec Produce Growers Association (Association des producteurs maraîchers du Québec)