It’s no surprise that asparagus is a popular plant for vegetable gardens. Not only is it a tasty and nutritious vegetable, but the plant itself is quite aesthetically pleasing, with fernlike foliage that is bright green in the summer and gold in the fall.
On the other hand, it is far from the easiest vegetable to grow. For one thing, it requires considerable patience, as the first full harvest does not occur for several years.
On the plus side, asparagus is a perennial plant. Once you do get your asparagus up and running, the same root system can continue to give you fresh asparagus for 15 to 25 years.
Follow these steps for successful asparagus growing:
1. Choose your site.
Asparagus grows best in deep, well-drained, soil with a pH between 6.5 and 7, amended with organic material that is rich in potassium and phosphorus. Choose an area that gets plenty of direct sunlight, preferably at least eight continuous hours daily. Consider planting your asparagus alongside tomatoes or parsley, two good companion plants for asparagus.
2. Prepare your site.
Meticulously weed the area of quackgrass and other perennial weeds the summer before planting. Once the asparagus is growing it becomes much more difficult to control weeds.
3. Plant your asparagus.
Late in winter or early in spring, when the temperature has reached about 50 degrees, when the soil does not clump when you handle it, dig one or more 6-8 inch deep furrows. Allow enough space for the asparagus to be 12-18 inches apart in a row, with 3-4 feet between rows. In addition to an inch of compost or manure, you may want to spread a handful of wood ashes and a handful of bonemeal in the furrow(s).
You can plant asparagus seeds or crowns, but most people plant crowns. Crowns are established root systems with dormant top growth. First soak the crown in compost tea for 10 minutes. Make little mounds in the furrow, and lay the crown on its side with the bud up and the roots spread out on the mound. Cover with 1-2 inches of soil.
4. Fill in the furrows.
As shoots emerge, fill in the furrow(s) gradually with soil. This compels the plant to grow tall before foliage appears. Be careful not to cover the shoots themselves. It will generally take until approximately the end of the first growing season to fill in the furrow(s) completely.
5. Tend the plants.
Make sure new plantings receive 1-2 inches of water a week. Once the plants are established, you need only water them about once every two weeks, in the absence of rain.
Side-dress the plants with a balanced organic fertilizer in late summer, and add organic mulch in the fall. Each spring before the spears appear, add fertilizer again.
6. Weed regularly.
In addition to using the mulch, remove weeds as they appear, being careful not to damage the asparagus roots. Don’t let weeds take crucial moisture and nutrients that should be going to the asparagus.
7. Watch for pests.
Two of the most common asparagus pests are aphids and asparagus beetles. Evidence of the asparagus beetle will be shiny black specks of damage on the speartips. The beetles themselves are orange and black and about 1/4 inch long. The pesticide Sevin is sometimes used against these beetles.
8. Cut the foliage between seasons.
Remove the foliage from the asparagus plants in late winter or early spring, before new spears appear out of the ground. Cut it down to ground level.
9. Harvest your asparagus.
You can harvest more asparagus each year as the plants mature. The first year, harvest zero. The second year, harvest at most a few of the thicker 6 inch or longer spears, but preferably harvest zero again. The third year, harvest the thicker 6 inch or longer spears for 2 weeks in the spring. In the fourth year, harvest such spears for 4 weeks in the spring. In the fifth and subsequent years, harvest such spears for up to 8 weeks in the spring.
Snap the asparagus off at the soil line, or carefully use a sharp knife to cut through the spear at an angle an inch or so below the soil line.
Following these steps should give you many successful years of asparagus harvests.
Deborah L. Brown, “Growing Asparagus.” University of Minnesota Extension Service: Yard & Garden Brief.
Martie Young, “Grow Your Own Asparagus.” The Master Gardeners.
“How to Grow Asparagus.” eHow.