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Planting Asparagus – How To Plant, Grow & Harvest Perennial Asparagus

When it comes to planting asparagus, a few simple tips can go a long way to big success, year after year.

Homegrown asparagus is in a league of its own when it comes to fresh, crisp, delicious flavor. Asparagus is one vegetable that no matter how fresh it might look in the supermarket, it can’t ever compare to the incredible taste of just picked spears from the garden.

And the best part is of all? Not only is it easy to grow and maintain but it’s a perennial crop as well. So with one year of planting, you can set yourself up for years and years of future harvests.

In fact, a single planting of asparagus crowns can keep on producing for 20 years or more. Now that is a serious return on a little planting effort!

growing asparagus
There is nothing quite like the joy of seeing asparagus spears poking through the soil in early spring. But the real joy comes when you taste the unbelievable freshness of a homegrown crop!

Here is a look at how to plant, grow and maintain your asparagus beds, and start enjoying the home-grown difference! Be sure to check out our YouTube video near the end of the article that walks you through the planting process as well.

Planting Asparagus – The Keys To Success

Preparing The Planting Area

Because asparagus is a perennial crop and will grow in the same space for many years to come, selecting a good planting location is vital to its long term success.

First and foremost, asparagus needs to be planted with the sun in mind. Select an area receiving at least 8 hours of full sunlight each day. Although asparagus will tolerate partial shade, it will thrive in full sun.

In addition to adequate sunlight, overall soil quality needs to be considered before planting as well. Asparagus grows best in fertile, loose, and well-draining soil.

Remember that your crop will be growing in the same space for up to 20 years or more. With that in mind, it is extremely important to fill the soil with nutrients from the start.

The best way to do that is by working in large amounts of compost before planting. Compost is the absolute king in helping improve soil’s fertility and structure. It not only provides nutrients to the soil, but also increases drainage, all while improving the soil structure.

digging in compost
Mixing in generous amounts of compost into your soil will pay big dividends for your asparagus crop.

For every 5 square feet of planting space, work in the equivalent of (2) 5 gallon buckets of compost. Aged or composted manure also works well as an alternative to straight compost. Either way, work those nutrients in before planting your asparagus!

From pitchforks to shovels and more, there are a wide range of gardening tools that can work well to work the compost in.

Planting Asparagus – Should You Grow From Crowns Or Seed?

Asparagus can be grown directly from seed, or from crowns. When planting a backyard crop of asparagus, growing from crowns is the far easier, and usually more successful option. It also leads to a much earlier harvest.

Asparagus crowns are the roots of 1 to 2 year-old asparagus plants. They produce an edible crop much quicker than seed because of their advanced stage of growth.

Seed crops, with their small, early growth, are difficult to keep weed-free during the early years. And nothing impacts a crops production levels like competing weeds! Asparagus seeds can also be hard to germinate, and are easily mistaken for weeds when maintaining the beds.

asparagus crowns
Although you can plant via seed, planting asparagus crowns is the far easier and faster way to grow asparagus. Crowns can produce an edible crop within the first year or two of growing, while seeds can take up to 3 years to develop.

Asparagus crowns can produce an edible crop the following year after planting. Unfortunately, when growing from seed, it can take up to three years to begin any type of sizable harvest.

Selecting Asparagus Plants

Asparagus plants can be either either male or female. And when it comes to growing in the garden, male varieties are usually the preferred choice.

Male plants tend to grow larger, and have higher spear production levels. Although there are a lot of varieties to choose from, we have had a lot of success growing Jersey Giant, Jersey Knight and Purple Passion at the farm.

Not only are they heavy producers, they have outstanding flavor as well. And let’s face it, purple asparagus makes for quite the conversation piece when placed at the dinner table!

asparagus types
Traditional green and purple asparagus are both wonderful options for the backyard garden. White asparagus however is not a variety, but the result of growing regular green asparagus in a completely dark environment.

Most local nurseries will stock crowns for planting, but you can also find several on-line nurseries who stock crowns as well. (see links below)

How To Plant Asparagus Crowns

Planting asparagus is best done using what is known as the trench method. To plant, begin by digging a trench 6″ deep and 8″ wide in the soil.

Next, place crowns at the bottom of the trench, water in, and cover with about 2″ of topsoil. Allow about 18″ between crowns, and 12″ between rows.

As the crown begins to grow through the soil, keep adding a few inches of soil, filling in the trench slowly. Eventually, the trench will be filled in completely over the course of a few weeks.  

This trench and fill process allows the asparagus to develop deep roots in the soil. All of which leads to years of excellent crop harvests.

First Year Growth & Maintenance

Here is the hardest part of planting and growing asparagus – you shouldn’t harvest spears until the second year. Unfortunately, although the crowns will send up some delicate spears, it is best to let them grow in year one.

Why? By allowing them to grow, it lets the crowns develop underneath the soil to their full potential. That means larger and better production in the years that follow. It is hard to do – but allow your crop to grow at will the first year. Once it has died off in the fall, you can cut it back to the ground.

In year two, you can harvest some spears early. Then, again allow the crop to grow to full maturity. After year two, you can harvest at will, but always allowing the plants to grow after until fall.

Maintaining The Crop – Mulching & Fertilizing Asparagus

The biggest key to growing asparagus successfully is keeping beds weed free. Weeds and grass compete for valuable nutrient. Unfortunately, beds that fill with weeds will result in smaller, less productive harvests.  

late summer care
Asparagus should not be harvested in year one. Instead, allow the plants to grow at will to develop stronger roots.

The best way to help keep weeds at bay is with a thick layer of mulch. Not only will it help suppress and eliminate weeds and weed seeds, it also keeps valuable moisture in the soil for plants.

We use either straw or shredded leaves to mulch and keep our beds weed-free throughout the year. A two to four inch thick layer will work well to keep beds under control. In late fall, we add a few more inches to help insulate and protect the crowns through winter.

We use shredded hardwood bark around the edges of our beds. Many tree trimming companies have large supplies on hand each spring from trimming trees.

Fertilizing – How To Plant & Grow Asparagus

Because they are a perennial crop, asparagus plants benefit greatly from added nutrients over time. As with any perennial, they can slowly drain the soil of nutrients as the years roll by.

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Fertilizing plants is best done in late summer / early fall, and once again, compost is all you will need. Simply pull back the mulch, and spread a few inches of compost around the base of each plant.

These nutrients will work slowly into the soil to help re-energize the soil and crowns. By doing this in late summer or early fall, it provides a valuable source of fresh nutrients for the following spring harvest.

Beyond that, there is little need for maintenance other than removing weeds. Once established, your asparagus beds will provide you with years of fresh and amazing tasting crops each spring!

Here is to growing your own delicious crop of asparagus this year. And even better, enjoying the fruits of your labor for years to come! For more vegetable gardening tips and secrets, check out our Raised Row Gardening category on the blog.

Happy Gardening! Jim & Mary