ASPARAGUS IN THE HOME GARDEN

When I bought my home in Thoreau, one of the first things I looked for was a place to put an asparagus bed. Asparagus is one of the earliest harvested vegetables each spring. The spears are crisp, tender, and essential to an asparagus lover!

I didn’t grow up eating asparagus. When I moved away from home, I tried the canned variety, which does not even resemble the taste and texture of fresh asparagus. That changed when I had a friend who lived in an old farmhouse. They had an orchard with asparagus planted under the trees and we had asparagus every week for two months. I was hooked! I steamed or boiled it (only for a few minutes) and served it with butter, Bearnaise, or cheese sauce. Now I grill a lot of the asparagus for a healthier diet.

Asparagus is for the long run. You plant asparagus in the spring and begin harvest two years after planting crowns and three years after planting seeds. The first year of harvest is only to pick the largest spears for three weeks. After that first year, you can pick asparagus for two months (as long as the spears are as wide as a pencil). Most plant guides say a plant can live for 15 years but most beds will last a lot longer. Some people break off the spear by hand close to the ground but I don’t like the stem that is left in my garden so I use a knife and cut below the surface of the ground being careful not to injure spears coming up near your cut.

Asparagus grows well in New Mexico. It does not mind soil and water being alkaline. It grows best with lots of sun, warm days, cool nights, low humidity, and is drought and salt tolerant. Everything New Mexico has.

Almost all of our vegetables are planted, grow to maturity, and eaten the same summer. Asparagus is called a perennial because it continues to grow for years. The edible parts of the plant are called spears. They are the stems of the summer plant which looks like a fern. The spears emerge from buds at the top of the root system called a crown. The root system is extensive and spreads up to ten feet deep and wide. The fern can also get large, six feet tall and three feet wide. Keep that in mind when you look for a place for asparagus.

Asparagus can only be harvested for two months in summer because the plant needs to build up energy to survive the winter and produce the crop for next year. The fern creates energy that will be stored in the roots to produce the following year’s spears. It is important to take care of the ferns even after the harvest is over to make sure you will have good future harvests. This is by doing three things: fertilize, water, and weeding. One year I had a worse than usual grasshopper invasion. They chewed all the ferns until they were dead. I was afraid they would not survive. Needless to say, they did not produce a good crop of asparagus the next year.

Because asparagus will produce for so many years, it is important to consider where you place them and how you prepare the planting bed. If you have never had your soil tested, this is a good time to do it. You can get information from the internet or from your county extension office which is listed at the bottom of this article.

LOCATION – Choose a sunny site. A fertile soil that holds moisture is an asset. On lava or bedrock, look for areas that have the most soil. You can always add more soil if needed. Asparagus will rot if drainage is not good, so be sure water does not sit for prolonged periods after rain. If you have an existing garden, place the asparagus bed at the north end of the garden so the tall ferns don’t shade the other crops. Avoid sites with established perennial weeds, particularly bindweed and nutsedge. You cannot just dig them out or pull them. They Will Return! Late spring frosts can kill emerging spears. Find an area that is not low-lying or exposed to frost. My plot is protected by wood fences but every year I have to save my early spears from freezing with buckets or protective cloth.

Varieties that do well in New Mexico include: Hybrids with only male flowers that produce no seed: Jersey Giant, Jersey Knight, and Millennium. They have high yields, tend to live longer, and produce more spears. Heirloom varieties are open pollinated: Mary Washington and Martha Washington do well here. They are very cold tolerant and produce larger but less spears. The asparagus seeds that germinate in your garden can be a benefit or a nuisance. There is also a purple variety that appeals to people who love the unusual. You can buy asparagus in stores, on line, and in gardening catalogues.

When you’ve decided where to place your asparagus patch, it is time to prepare the bed. In May, or when your ground has warmed to around 50 degrees, you can plant the asparagus you bought. Dig a trench where the crowns will be planted. If you have clay soil, make it six inches deep and if you have sandy soil, go twelve inches. Place the dirt to the side to be returned to the trench as the ferns grow. Allow 12 inches between crowns and three feet between rows. You can plant a single row that is 10 feet long for 10 asparagus plants or several shorter rows each three feet apart. Plant the crowns along the trench either “head to toe” (bud to root tip) or spread the crown out in the middle of the trench like an octopus. (Just don’t put the crown upside down--that will delay growth). Adding a fertilizer at the time of planting will ensure good growth. Use an organic balanced fertilizer(10-10-10) or compost that has no fresh manure that may burn tender roots. Cover the crown with 3-4 inches of the soil that was removed from the trench. The rest of the soil will be added gradually as the ferns grow. Make sure you don’t bury the thin stalks or break them off from hard soil clods. After planting, water the buried asparagus crowns well. The narrow spears will start coming up in two to three weeks. Keep your asparagus growing well by giving them at least one inch of water every week if no rain. If soil is sandy, water more often. Control weeds because they will compete with the asparagus for water and nutrients. It is important not to damage the asparagus roots. Remove weeds by hand or shallow hoeing. You can also use cover crops or mulch.

There are two ways to plant asparagus seeds. One way is to plant 2 to 8 seeds in pots that are 4-5 inches deep. Cover with ½” of seed starting soil, wet well, and cover with plastic wrap or a tray top to keep the soil from drying out. Keep the pots at 70 %F either with bottom heat or a warm room. The seeds will germinate in 2 to 4 weeks. Once they start germinating, remove the cover and put them in bright light. When the weather has settled in early summer, plant the asparagus that is several inches tall into the same trench you would dig for crowns. You will have to be more careful about adding the dirt as they grow. Asparagus seeds can also be planted directly in the garden. Prepare an area for babies to grow their first year. It should be level, have sandy soil, and will need one foot between rows with seeds spaced 2 to 3 inches apart. Wait until the soil is 70 ℉ and water daily until germination. The plants stay in this bed until next spring when you dig the plants in early April and move them to their permanent location. For established beds: Fertilize in early spring before the spears come up. Harvest spears as directed above. In July, fertilize again and continue watering and weeding during the summer. In October, as the ferns start to turn yellow, decrease watering which will signal the plant’s roots to shut down and harden off for winter. When the stalks are brown, cut them down at the surface and remove them to reduce overwintering sites for insects and diseases. This is a good time to add two to three inches of compost to give protection to the crowns in winter and extra an start in the spring. Now for the eating! Wash the spears of dirt and place them on a cutting board. Starting from the bottom end, cut at 1” sections until the spear turns tender and the knife meets little resistance. You can break the spear with your hand but it is not a very accurate way to determine tenderness. Also, you can cut off 1” of the bottom and shave the outer layer with a vegetable peeler for more tender spears. Steam or cook asparagus in ½” water for three to four minutes. If they have turned dull green, you cooked them too long. Asparagus is great on the grill. Puncture the spears several times with a fork and soak them in a salt solution for 15 minutes. Dry them off, have the grill temperature low, and cook them for 10 minutes. Check out the internet for other ways to cook asparagus.

Enjoy your asparagus. Plan for the future. PLANT ASPERAGUS!

Edith Iwan is a Cibola-McKinley County Master Gardener who lives and works in Thoreau. As a Master Gardener she assists the County Cooperative Extension Service in providing accurate, research-based gardening information to county residents. If you have any gardening questions, please call the NMSU Cibola County Extension at 505287-9266 or NMSU McKinley County Extension at 505-863-3432