By Ajay Nair
A worldwide crop that is one of the first to be available for harvesting in the spring, asparagus is one of the most popular vegetables grown by home gardeners and commercial producers alike.
The commercial production aspect of asparagus is discussed in a new Iowa State University Extension and Outreach publication written by Ajay Nair, assistant professor and extension vegetable specialist at Iowa State University, and Brandon Carpenter, agriculture specialist with Iowa State University Research and Demonstration Farms.
"Commercial Asparagus Production" (HORT 3059) is available online through the Extension Store.
“More and more growers who are entering into the production arena are in it for the long term and asparagus is a long term plant,” Nair said. “These new growers see that the local foods movement is going to continue to expand so they are thinking about the kinds of crops consumers in the state want to buy. Since asparagus comes into the market first in the spring, growers can receive a better price for the vegetable before other crops begin to reach harvest.”
The publication highlights all aspects of production, from site selection to post harvest care. An in-depth discussion of hybrid cultivars is included and can be used by producers to determine the type of asparagus that is best to be planted.
“Asparagus has both male and female plants; we want to make sure that growers understand the difference and that they plant the male one,” Nair said. “Male plants establish quickly, produce higher yields and don’t make berries which can consume energy that would otherwise go into the crown.”
Proper fertilization, weed management practices and how to combat insect pests also are covered. The most common pests in asparagus are discussed in detail, including management strategies that can help keep the crop healthy.
No asparagus should be harvested during the first two years after planting, with the first harvest coming early in the plant’s third year. Starting with the fourth year, asparagus has a six to seven week window for harvesting, resulting in 22-24 harvests per season.
“This crop does not provide instant gratification, but once it is established it will yield for the next 15-20 years,” said Nair. “Taking care of the crop initially will allow it to establish and adapt well to our soil and weather conditions and allow for sustained yields."
Information on yields from field trials conducted at Iowa State University Research and Demonstration Farms also are included in the publication.