Asparagus Grows in USDA Hardiness Zones 3-8

Humans have been growing asparagus spears for over 2,000 years, and for good reason. It’s a perennial vegetable that can produce for up to 20 years or so! Now THAT’S a great reason to dedicate a “forever asparagus bed” to the amazing asparagus plants, (and presuming you and your family also enjoy eating it)!

Delicious, nutritious and versatile, this wonderful perennial vegetable takes awhile to grow up to its full capacity. However, once it does it will serve your family for many years to come.

However, if you’re interested in growing asparagus commercially, as a market gardener or farmer, it’s recommended to clear your asparagus fields after 10 years. Apparently, the yield begins to decline after a decade of production and as the plant roots grow more dense, they become more susceptible to fungal pathogens such as Fusarium spp., which cause the roots to rot and can spread to crown rot.^[1]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7022954/#B19-metabolites-10-00017 

Asparagus can produce for 15-30 years in the home garden, and for 10 years as a commercial crop.

GROWING ASPARAGUS

How Long Does it Take Asparagus to Grow?

It takes four years for asparagus to reach its full production capacity. However, you can reduce the time to fuller harvests by planting one year old crowns or two year old male crowns. [#affiliatelink]

Until then, you can harvest lightly beginning in the second year. Once in full production, one asparagus plant can produce up to a half pound per week for up to eight weeks.

We’re growing asparagus and just added a second asparagus bed this year, (2021). It turns out we didn’t have nearly enough to satisfy our family’s love of this unique vegetable. And given the long-lived production plus high nutrients, it’s a no-brainer to give this perennial vegetable a permanent home in our little garden.

If your family wants to munch on asparagus regularly in season, you’ll want to plant around 10 plants per family member.

Sure, you have to be patient when growing asparagus, but it’s so worth it for this perennial vegetable will continue producing for an average of 20 years. Plant it once, practice a little patience then reap the rewards for many years to come.

It takes 4 years for asparagus to reach its full production capacity. For best results, plant 2 year old crowns.

Favorite Varieties of Asparagus

• Jersey Giant – hardiest and highly productive medium to large spears and is especially good asparagus for colder climates
• Jersey Knight – highest quality yield of the Jersey asparagus varieties and highly disease resistant
• Mary Washington [#affiliatelink] – purple tinged tips with heavy yields; long lasting tight buds
• Sweet Purple [#affiliatelink]- sweet deep burgundy spears with 20% higher sugar content especially good for raw salads or as crudités

When to Plant Asparagus

In our NC zone 7a, we plant asparagus in winter, from mid-January to mid-March, while the plants are dormant.

Plant Asparagus in Winter to Early Spring

Regardless of your growing zone, a good rule of thumb is to plant asparagus roots in late winter or early spring as soon as the soil is not frozen and is dry enough to dig an 8 inches deep by 12 inches wide trench.

Where to Plant Asparagus

• In sandy soil, 8″ deep x 12″ wide rows
• Raised beds or rows with good drainage and free of perennial weeds
• Full sun (partial shade tolerant)

Raised garden beds work well for asparagus, for they thrive on deep, rich, well-drained soil. We’re growing asparagus in our hugelkultur bed as well as a wood frame raised garden bed. Raised beds can also facilitate earlier planting time without having to wait for the idea soil temperature and structure.

While asparagus can tolerate partial shade, you’ll get the best production and healthiest growth if you can plant asparagus in full sun. For best results, plant asparagus in sandy soils that have been well amended.

How to Plant Asparagus in 8 Steps

Plant asparagus from the roots of male plants. For vegetable gardening, plant only male asparagus plants as they are more productive in food value.

The female plants add ornamental value with their bright red berries that can add color interest and fern texture to edible landscapes and foodscaping. However the asparagus female plants do not produce as much in edible spears because they use up a lot of their energy making beautiful — but inedible — berries.

If asparagus roots (called crowns) are dry, soak them in water at least 30 minutes before planting. For best results, add recommended amendments.

We like to put mix the compost together with the amendments in a 5 gallon bucket or wheelbarrow, then shovel (or scatter from the bucket) the amendments into the bottom of the trench.

1. SOAK asparagus crowns if dry
2. DIG a 8″ deep by 12″ wide trench in row or raised bed
3. MIX compost with soil amendments as indicated below
4. SHOVEL amended compost mixture into 3-4″ mounds at bottom of trench at 12″ intervals
5. PLANT crowns by placing an asparagus root upright on each mound at about 2″ below ground level or what will be the top of your raised bed or row.
6. TOP with 2 inches of soil that’s roughly 70% compost mixed with 30% amendments to 2″ over the top of asparagus crowns
7. WATER your new bed
8. MULCH is optional and has its pros and cons.

If you choose choose mulch to help with weed control, use good organic mulch such as the deep mulch gardening method. We use free wood chips for our garden, and prefer a mulched garden for a cleaner pathways and fewer weeds, however the downside of mulch is that it gives more places for pests to hide and reproduce.

As with many things in the garden, there’s no one right way and sometimes we have to choose the one with fewer negatives, or that which suits our preferences and circumstance.

Soil Amendments for Planting Asparagus

• Organic compost
• Test soil pH a minimum of 7 days prior to planting;
  • ideal pH is 6.5
  • add lime if soil pH is below 6.0
• Add 2” of compost in the trench along with lime and bone meal, (according to package instructions)
• Mix backfill soil with ~30% compost

When to Fertilize Asparagus

Fertilize your asparagus plant in mid spring with two to three pounds of 10-10-10 fertilizer [#affiliatelink] or organic compost and amendments per 100 square feet.

When to Water Asparagus

Asparagus is happiest with moist soil and a weekly deep watering. Asparagus roots grow down to ten feet deep, so deep watering helps to insure that all of the roots are being watered.

Stages of Growing Asparagus

• GERMINATION: 21 days or more
• TRANSPLANTING: ~3.5 weeks to reach 2″ for transplanting seedlings to the garden
• MATURITY:
  • ~3.5 years
  • Can produce for 20 years on average after year 4
• YIELD (average):
  • ½ pound / week x 8 weeks per season from years 4-20
  • 4 pounds of asparagus per plant per season
  • 64 pounds of produce for the life of the plant for 16 years of optimal production.

Common Asparagus Pests

• Beetles –
  • Asparagus beetle
  • Spotted asparagus beetle
• Slugs
• Snails
• Worms –
  • Armyworms
  • Cutworms

Apply beneficial nematodes in the fall to help set protect your asparagus come spring. Beneficial nematodes can overwinter deep in the soil and surface hungry and looking to devour asparagus beetles and other pests.

Common Asparagus Disease

• Cercospora
• Fusarium Wilt
• Gray mold
• Rot –
  • crown rot
  • root rot
• Rust / needle blight

When to Harvest Asparagus?

• HARVESTING ASPARAGUS:
  • Late April-July
    • Harvest asparagus spears at six to eight inches tall
    • Young plants produce for 2-3 weeks
    • Mature plants produce for 6-8 weeks
  • Harvest Asparagus:
    • Harvest sparsely in year 1, at less than 20% of spears, which helps stimulate more growth.
    • Full harvesting begins in 3rd year, clipping at the base of plant.
    • Harvest 7-9″ stems every 2-4 days, including skinny spears.
    • Leave 2-3 spears minimum on each plant during growing season.
• PRUNING: Cut back asparagus ferns after foliage dies back fall.

How to Harvest Asparagus

To harvests asparagus, cut or snap the spear below the soil surface, at or above the soil surface. Whether you cut or snap the asparagus doesn’t seem to make any difference to the plant in how it grows and sends up new shoots. However, the spears tend to snap near the base, leaving the woody stem part behind, so there’s less trimming off required.

For more on harvesting asparagus.

Reasons to Grow Asparagus

Asparagus is more than a unique and attractive perennial vegetable that makes your pee smell funny.

Asparagus Benefits

• Antioxidant
• Anti-inflammatory
• Low in calories / aids in weight loss
• Diuretic (due to the amino acid asparagine)
• High in fiber
• Great nutrients, including:
  • folate
  • vitamins A, B6, C & K
  • potassium
  • thiamin
• Improves digestion
• Support healthy pregnancy
• Lowers blood pressure
• Fights cancer

Asparagus Uses in Traditional Medicine and Cosmetics

Asian cultures have used asparagus in traditional medicine for centuries. Asparagus root extract is used as a tonic in Chinese medicine and in India, Asparagus officinalis root extract is used to aid female reproductive health, as well as a tonic for the lungs in consumptive diseases such as tuberculosis (TB).

Asparagus contains the non-essential amino acid asparagine, which is used in cosmetics to help with the absorption of moisturizers.

SOURCE: A Consumer’s Dictionary of Cosmetic Ingredients [#affiliatelink]

Asparagus Nutrition

Green asparagus is in the top ten list of healthiest foods in the world. White asparagus is also nutritious, however not as rich in nutrients as antioxidants as the green and purple asparagus varieties, and likely because white asparagus is grown without sunlight and deprived of the photosynthesis that brings on the green.^[2]https://www.livestrong.com/article/541837-nutritional-value-of-white-asparagus-vs-green/

Here’s a fantastic asparagus nutrition chart by HerbaZest.

Why Does Asparagus Make Your Pee Smell Funny?

That funky smell in your urine after eating asparagus is caused by asparagusic acid which breaks down into a smelly sulfur compound when digested.

Apparently, asparagus is the only food to contain the chemical asparagusic acid, which name it bears its name. While this odiferous effect may not be pleasant, it’s not so much that it’s awful, it’s just different and definitely notable almost immediately after consuming asparagus.

How to Prepare Asparagus

Our most favorite way to enjoy asparagus and other vegetable is as roasted vegetables.

What is the Healthiest Way to Prepare Asparagus and Does Cooking Diminish Nutrients?

While consuming raw vegetables presents higher values of C and B vitamins, these are actually destroyed at heats high enough to cook the veggies. However, interestingly, cooking can render other nutrients more bioavailable.

“Mushrooms, asparagus and cabbage supply more antioxidant compounds when cooked compared with raw. And antioxidant compounds in foods we eat may help protect against cancer and other diseases.”
~Sharon Palmer, RD

Ways to Prepare Asparagus

RAW: Some ways to enjoy it raw is to snack on it as a crudité finger food, the way your would celery and carrot sticks, with or without dips like guacamole, hummus or your favorite salad dressing.

We also enjoy chopping up raw asparagus for crunchy variety in salads or as finger food along with other crudités. But there’s no limit to ways to enjoy asparagus.

STEAMED: For the highest retention of nutrients, asparagus is best al dente or lightly steamed until just tender. We find asparagus delicious on it’s own, without the need for any seasoning. Of course to add seasoning can definitely enhance it and provide many variations to enjoy.

The next healthiest way to enjoy it is to steam it until tender and then to lightly drizzle with lemon juice and olive oil.

ROASTED: As indicated earlier, we love roasted vegetables. Just toss with a little olive oil, salt and pepper and roast or bake at 375°F for ~20 minutes. You can of course also roast it with other similarly sized foods like onions, garlic, mushrooms and summer squash.

And, here are some more favorite was to enjoy asparagus.

Delectable Asparagus Recipes

• Orange-Glazed Salmon with Asparagus
• Mediterranean Roasted Vegetables
• Grilled Asparagus With Gremolata Sauce

Now, that our mouths are watering, let’s move onto growing asparagus!

How to Grow Asparagus

Coleman talks more about the stages of growing asparagus in this video.

Contributions from the Community

“Planted about a hundred crowns each of Jersey Supreme, and Purple Passion. The Jersey Supreme never did well in our soil. The Purple Passion produces very well. They’ve both been in the ground for eight years.”
~Kris Gasteiger, WV

So the moral of Kris’ story is twofold.

Two Lessons on Growing Asparagus

1. If at first you don’t succeed, it doesn’t mean you can’t grow asparagus!
2. So when planting asparagus, it’s advisable to plant more than one variety

Top feature Image by Yvonne Huijbens from Pixabay

Thanks for visiting and we hope you’ll come again soon. Let us know if you have any questions or tips to add.

Let’s keep on growing!