1. Asparagus initially came from the eastern Mediterranean area and was brought to the Americas by early explorers.
2. Garden asparagus commonly escapes cultivation and grows wild in many areas of the world.
3. Historically, asparagus was used medicinally rather than as a food plant.
4. In ancient Roman times, Emperor Augustus enjoyed asparagus that was dried for use in the off season. This led to the term “quicker than you can cook asparagus”.

Asparagus is high in vitamins A,C,E, K, folate, riboflavin, thiamine and fibre. Check here for detailed information from the USDA National Nutrient Database for Standard Reference.

The Canadian Food Guide recommends that roughly half of the food on your plate should be fruits and vegetables.

Asparagus transplants and crowns should be planted out in spring or early summer, as soon as the ground has thawed and soil can be easily worked.

If growing asparagus from seed, start seeds in February for planting out as transplants in spring.

The timing of planting should coincide with your frost-free dates. We've given suggested dates below, but you can adjust these to your local conditions. 

• Knowing the last expected spring frost date for your location will help you plan when to sow seeds. The date is based on averages and varies according to where you live – it is as early as mid-May for Saskatoon, Estevan and Swift Current, SK, while Yellowknife is May 30 and the Moosonee region in Manitoba is June 10. Find the date of the last spring frost at this link: https://climateatlas.ca/map/canada/lastspring_baseline# Click on where you live on the map.
  

Although seeds can be directly planted out in spring, they need at least one more year of growing compared with transplants to become a productive patch.  It is best to start seedlings indoors in February for planting out in spring.  

Plant seeds 0.5 cm deep in a soil-less mix made of peat or coir, mixed with a small percentage of vermiculite and/or perlite. Choose a 4" pot (or larger) with a hole at the bottom to accommodate and encourage a large root system. 

Asparagus seed is slow to germinate: it can take up to two weeks at room temperature. Asparagus seeds benefit from warmth. Use a heat mat if you have one, or place containers in a warm place like the top of the fridge until they germinate.  Place a clear dome or plastic over the seeded containers to keep moist until germination.

Once seedlings have emerged, place them under grow lights or set them in front of a south-facing window.

Asparagus plants are very tender and fragile when they emerge. To avoid seed rot, do not overwater. Allow the soil to dry out very slightly in between watering. 

Begin fertilizing asparagus seedlings once/week with 20-20-20 water-soluble fertilizer after the seedlings have emerged and are at least 5 cm tall.  Mix the fertilizer according to label directions. 

Seedlings should be hardened off before planting outdoors.

Since asparagus is a perennial crop, it is very important to prepare the soil in the asparagus patch with care and attention.  Choose an area with loam to sandy loam soil.  The soil must have good drainage.  Poorly drained soil will promote Fusarium crown rot disease. 

Before planting, add a layer of well rotted manure (at least 5 cm thick).  Work the manure into the soil and ensure the area is worked well. 

Asparagus transplants and crowns should be planted out in spring or early summer, as soon as the ground has thawed and soil can be easily worked.

Planting instructions for crowns (roots) or transplants

1. Dig a trench at least 20 cm deep. 
2. Plant crowns or transplants in the trench 30 cm in the row and allow 2 m between rows. Cover seeds with  and transplants with 5 cm of soil.
3. After planting crowns or transplants, water in with 10-52-10 fertilizer mixed according to label directions.  This fertilizer is high in phosphorous and will encourage root growth.
4. As the growing season progresses, fill in the furrow a little with more soil every few weeks. Cover part of the plant but never bury the entire plant.  By the end of the growing season, the trench should be level with the surrounding soil. 

Other cultivar recommendations:

1. Here are cultivar recommendations from the North Dakota State University Cultivar Trials, as they share a similar prairie climate and soils. You may download their list here: North Dakota State University Vegetable Cultivar Recommendations for 2021
   • •  'Jersey Giant', 'Jersey Knight', 'Jersey Supreme', 'Millennium', 'Purple Passion'

While new seedlings need moisture for good growth, it is very important not to overwater your new asparagus patch.  It is best to water less frequently but deeply: about 2.5 cm of water every 7 - 10 days depending on your soil type. Allow at least the top 2.5cm of soil to dry thoroughly before watering.  Wet soil conditions encourage the development of Fusarium crown rot. 

Keep your asparagus patch weed free.  Weed control in perennial crop areas can be a challenge.  Use a shredded arborist woody mulch or seed-free straw mulch between rows to keep weeds down. 

As the season progresses and harvest ends, the asparagus patch turns into a ferny hedge by mid-summer.  Weeding can be a challenge during this time but it is critical to keep weeds to a minimum in this perennial crop.  

Once the asparagus ferns turn yellow and die in the fall, the ferns should be either mowed or removed from the patch in fall.  Gardeners at northern latitudes tend to leave their asparagus ferns in place over winter in order to catch snow to provide extra frost protection to the asparagus crowns.  This is a good practice unless you have noticed asparagus beetles in your patch; most notably, the common asparagus beetle and the spotted asparagus beetle. In that case, mow the ferns to ground level to prevent beetles from overwintering. 

Blanching asparagus

Have you ever wondered how white (blanched) asparagus is grown?  To blanche asparagus mound soil or mulch around the spears in early spring to completely cover them. Another way is to cover crowns with an opaque bucket or box to exclude light.

These mounds exclude the light and limit the amount of chlorophyll that is produced, which results in white spears.  Harvest the blanched spears by digging into the mound. 

Asparagus is not suited to fall seeding.

Asparagus can be a challenge in the far north, but it is possible. Asparagus is rated to Zone 2 Plant Hardiness rating.

Asparagus needs a deep layer of soil: 30 - 35 cm or deeper, which can be difficult if you live in an area where soil is thin.

Grow asparagus from crowns instead of seeds. Crowns are available from many on-line seed suppliers. 

An asparagus patch in the far north may benefit from extra winter protection. If you have access to mulch such as straw, lay a thick layer of mulch over the asparagus patch just before the ground freezes. 

If not, bank extra snow over the patch throughout winter to help insulate the soil. 

Here is how Louise Piche grows asparagus in Dawson City, Northwest Territories: 

Fresh northern asparagus

See our preservation section for more videos.

Not applicable.

Seed saving is not recommended for asparagus. Although asparagus do produce seeds inside round red berries produced by female plants in the fall, there is little control in the quality of plants produced from saved seed. 

If you want to grow asparagus from seed, we recommend purchasing asparagus seeds. 'Guelph Millenium', a top producing asparagus is available as seed from seed catalogues.

Spears should be harvested when they are 10-20cm (4-10”) in length.  Old spears will be fibrous.  Cut spears with a sharp knife up to 5cm below the soil line.

For longer term storage, we recommend freezing, fermenting, dehydrating (drying) or canning.

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