Unlike most vegetables, asparagus is a perennial, meaning it lives for more than two seasons. It takes a couple of years to mature before you can harvest and enjoy it, but it lasts for many years. It’s a vegetable that will stay strong and grow bigger and bigger for decades, feeding your family for generations. Although supermarkets stock both canned and frozen asparagus, neither compares to the unique flavor you get from freshly harvested and picked asparagus. Once an asparagus bed is established, asparagus is the first vegetable that is table ready in the springtime and will provide your family with a firm and fresh vegetable treat for up to 20 years, each crown in your bed producing up to 1/2 pound of spears per year.
Plants can be started by seed or you can buy one-year-old crowns from the greenhouse or garden center. Buying year-old plants means you can start harvesting a year sooner. It is best to start with asparagus crowns rather than seed. They are much easier to handle and plant, plus they will be ready to harvest in two years, rather than three. When you’re buying asparagus, look for:
- A variety that will grow well in your zone
- Bundles of 10 to 25 crowns, with firm, fresh roots
- A bundle that is predominately male, as they yield better. Check the plant’s label to find out the mix of male and female plants, as the mix isn’t evident until the plant blooms. If you want to select for all-male plants, then look at your asparagus plants with a magnifying glass once flowers appear. Female plants will have pistils with 3 lobes, males will be larger and longer than females. Pull out all of the female plants and transplant the males to your permanent bed next spring. Popular male varieties such as Jersey Giant and Martha Washington are great choices for those looking for maximum yields.
Starting with Crowns
Great crowns will cost you anywhere from $0.75 – $1.50 per crown. Crowns from a wholesaler that grows the asparagus crowns themselves and got 50 of them for $37.50. Which is cheap. If you’re buying them from someone other than a wholesaler expect to pay twice as much. Asparagus is planted in early spring as soon as the bed can be worked. You want to find a good sized permanent spot that will be used only for the asparagus. Asparagus prefers full sun, although it can tolerate a little bit of shade. Selecting a spot where your asparagus will have optimal sun conditions is best, especially given that it will keep returning year after year. Asparagus foliage will grow tall enough to shade any surrounding vegetation, so it is usually grown in a prepared bed of its own.
Preparing the Bed
Create a lush nutrient-rich spot. Dig the bed well, loosening the soil and adding amendments such as compost and manure. Take a bit of extra time to weed the spot well. Be sure that your planned planting site is completely and totally weed-free. Asparagus does not like competition from other weeds. It’s a good idea to mulch the area very heavily to help prevent weed growth.
Some people advise soaking your root crowns in compost tea for about a half hour prior to planting. If you don’t have compost tea on hand, you can use just water. The goal is to fully hydrate the root mass and make it a bit more pliable and easy to spread. Asparagus crowns are planted in trenches, so you’ll want to dig your trench to a depth of at least 8 to 12 inches and 12 to 18 inches wide. Make mounds down the center of the trench to plant the crowns on. A great idea is to use compost for the mounds, but the garden soil will work as well.
Caring For Asparagus
You can sprinkle a small amount of hardwood ashes and compost or well rotten manure in the bottom of the trench. Space each mound around a foot apart. As the crown begins to grow through the soil, keep adding a few inches of soil until the soil level has filled in the trench over the course of a few weeks. This process allows the asparagus to develop a deep root system to provide for years of crop harvests. Water regularly in the first year to assure the roots have ample moisture to get established. Optimal temperature range for production is between 75-85 degrees Fahrenheit during the daytime, 60-70 degrees at night. In that optimal range, it’s not uncommon for an established plant to grow three to six inches of asparagus spears per day.
Fertilize with compost or rotted manure mixed with hardwood ashes twice a year. Once in the very early spring before the asparagus spears begin to appear and again in the early summer after the harvest time has ended.
3 Years Period
For the first year after planting, do not cut or harvest any stalks. They need to be allowed to grow into the asparagus ferns that feed the roots so they can survive the first winter. In year two, you will begin to see some small spears shoot through the earth in the spring. You can harvest the first week or two of spears, then allow the plants to once again grow tall and build up strength. The year 2 spears will be smaller, but still very tasty. By the third year, you should be able to start cutting some of the larger spears. You’ll want to leave the smaller spears to grow up and fully frond out, so that they’ll feed and support the root system. After each spring harvest, let your asparagus grow tall in the beds and repeat the process of cutting back after they have died off in the fall.
To harvest asparagus spears, use a sharp knife and cut the spear off. Some growers prefer to do this just under the surface of the soil. If you do that, be careful to avoid cutting other spears that may be forming under the soil’s surface. You can also simply grasp the spear and bend it to snap it off just above the soil surface. Harvest spears when they are 6 to 10 inches high and the tips are firm and tight. Do not harvest spears smaller than ¼ inch thick. You can harvest them when they’re shorter if you’d like, but you’ll have less asparagus that way. Extend the harvest each year by 2 weeks until you are harvesting for 6 weeks. Pick asparagus every 3 days, more often in warm weather. Asparagus is best when eaten within 24 hours, but can last several days in the refrigerator.