Organic Gardening: Growing great asparagus
Driving west on Interstate 94 in midsummer, the trained eye can spot asparagus ferns growing on the freeway embankments from a fast-moving car. It’s a distinct shape, tall and willowy, like a puff of green smoke. Asparagus takes advantage of areas like roadsides and railroad tracks that are too sandy or too salty for other plants.
That asparagus grows wild is one of several unique features that make it different from other crops. Unlike most garden vegetables, asparagus is a perennial, sending up shoots from roots or “crowns” that were fattened on last year’s ferns. Importantly, it can take several years to establish a patch of asparagus that is strong enough to withstand harvesting. The rule of thumb is that crowns can be planted one year and then harvested for the first time two years later. If you’re growing asparagus from seed it takes three years, with transplants requiring about 12 weeks of growth before planting.
The benefit of the work and patience required to start your own asparagus patch is one of the first vegetables of spring and a product that is superior to anything found in stores. In this respect, asparagus is similar to sweet corn because it’s a vegetable that quickly loses its sugar content and thus its eating quality if left to sit on the shelf. Once established, plants will often produce for 20 years or more.
Like other common vegetables, asparagus needs a lot of sun. Those planting crowns usually do so in trenches 12 inches deep, with the spidery crowns laid out every 18 to 24 inches. As the spears and ferns grown, periodically add soil to the trench until it is filled in. Allow for 5 feet between rows.
Mulching with straw is a good idea so perennial weeds don’t get established in the asparagus patch. This will also cut down on the need to water. Jersey Knight and Jersey Giant are popular varieties that do well on account of being all male plants that don’t make seeds and have more energy for sending up shoots.
A good top-dressing of compost is necessary at planting and in subsequent years. Growers can plant a green-manure of white clover between rows to keep weeds down and add nitrogen. Leave old ferns over the winter to protect the crowns and then add them to the compost pile in spring. Water asparagus plants well for the first few years and then during dry spells thereafter.
Once an asparagus patch is harvestable, gardeners will usually cut the spears off the plant for a week the first year, two weeks the second and three the third, maxing out at a month to six weeks of harvest thereafter. Plants will often let you know when the harvest is over by putting up thinner, more spindly spears, a sign that the plant is stressed and needs to begin producing food for itself. These spears then turn into the 4- or 5-foot tall ferns that grow all summer and sometimes produce small red berries that make them look like strange Christmas trees.
Spears are best cut on the small side, 8 inches long or so, before they begin to sprout branches from the tip of the spear. Cut them off just beneath the surface of the soil and store them in the refrigerator until you can cook them.
Try not to overcook your spears. Asparagus is best grilled, steamed or fried for a short period of time or even eaten raw. Asparagus soup is an exception if you have a taste for it.
Also, be warned, as is commonly known, asparagus may produce odoriferous urine in some users. Scientists are currently debating whether this difference is due to the way asparagus is processed by different people or if it’s caused by variations in the sense of smell between individuals. No doubt enlightened inquiry will soon get to the bottom of this. In the mean-time it’s a small price to pay for savoring one of the earliest and perhaps best vegetables the garden has to offer.
Brian Allnutt is a freelance writer and organic gardener in Metro Detroit. You can reach him at firstname.lastname@example.org.