Growing Asparagus

April 30, 2024

Ever wonder how asparagus is grown?

Every spring, we harvest bunches of delicious asparagus. Asparagus, Asparagus officinalis, are the edible shoots, commonly called spears, that rise early in the season from underground stems called crowns. These perennial plants require patience and at least a few years to become well-established. I made sure an asparagus crop was planted when I first bought my farm. I also now have a large asparagus bed in my new vegetable garden. And while we're careful not to harvest too much too soon, this patch is already proving to be very productive.

Enjoy these photos.

: I’ve been enjoying homegrown asparagus for many years. The asparagus crop in my flower garden is already more than 10-years old and well-established.

: When I created my new half-acre vegetable garden last year, I made sure one of the biggest beds was earmarked for asparagus.

: These are asparagus crowns from Johnny’s Selected Seeds. Each of these is about a year old. Asparagus crowns usually come in bundles of 10 to 25 bare-root plants.

: Asparagus has modified adventitious roots that swell to store food and to support the plants.

: Asparagus grows in trenches like these. Depth of planting is critical. If too shallow, the plants will produce a large number of small spears. If planted too deep, the spears will be large, but few in number. These furrows are at least eight-inches deep and a foot wide.

: Asparagus roots grow very deep because they can survive very long in the soil.

: Here they are lined up in the trench. Last spring, we planted two varieties – ‘Purple Passion’, which produces attractive purple spears with a mild, nutty flavor and are reputedly sweeter than most other asparagus varieties. And ‘Millennium’ – a productive plant that produces high-quality spears that are tender, green, and delicious.

: Asparagus needs lots of room to grow. The crown and root system can develop to an enormous size – about five to six feet in diameter and 10 to 15 feet deep. When planting, the roots should be splayed to direct the root growth outward and not downward.

: Once all the crowns are positioned, the trenches are covered with several inches of soil. As the weeks progress and growth appears, the rows are backfilled a bit more making sure the tips of the shoots are all but completely covered.

: Asparagus beds require consistent soil moisture during the first growing season. Once established, the plants are relatively low-maintenance.

: By June, the bed is full of growing young ferns. This fern production is crucial to the success of a developing asparagus patch. The number of spears produced each year and the overall health of the plants, is affected by how many ferns are left to mature.

: The bigger the ferns, the more food is created to fuel the following year’s spear production.

: First spears can appear within a couple of months after establishing an asparagus patch, depending on soil temperatures and moisture, but they should be left alone, so the plants could start to develop and become more established.

: And here is the bed last August. The asparagus ferns are more than four-feet tall. The food produced travels back down to the crown and the roots of the plant in fall as the fern dies back. The carbohydrates are held in the dormant crowns through the winter.

: And then earlier this month, the heads of stronger, more robust spears poked out of the soil.

: ‘Purple Passion’ asparagus is nuttier, sweeter, and more tender than other green varieties because it has about 20-percent more sugar in its stalks. While the stalks are purple on the outside, the inside is the same as a green spear.

: ‘Millennium’ asparagus is high yielding, long lived, cold hardy, and adaptable. The best time to harvest is when the asparagus spears are about six to eight inches tall. Harvesting can be done by breaking the spears off by hand near the soil level.

: This is an earthenware cloche specifically for growing white asparagus. The plants are the same, but the spears of white asparagus are blanched, or kept from light while growing. Crossing fingers they’re white under there.

: It’s widely thought that thin asparagus are tastier, based on the notion that slender spears are younger. However, thick spears are already thick when they poke up from the soil. The two are just different varieties. I love both kinds of asparagus, but I do find that fat stalks tend to be a little more succulent.