Unlike most vegetables, asparagus plants are perennial, which means the same plants grow in your garden year after year. The spears that we enjoy as a vegetable are the new shoots that emerge in spring. The most important part of growing asparagus is to realize that it will take a couple of seasons before you taste the first bite of homegrown asparagus. Plants need to be allowed to mature before you can harvest. They will remain in the same place in your garden for many years—15, 20, sometimes 30. In fact, a productive asparagus bed is a good reason to renovate your house, rather than move!
Asparagus can be grown in most parts of the country, but does especially well in cooler regions with longer, colder winters. These periods of dormancy allow asparagus stalks to grow more robustly in the spring than they do in warmer regions with milder winters.
Planting asparagus is like preparing for a trip. Careful preparation makes the journey easier. It is the same with asparagus. Before you buy the plants, you need a prepared bed. Hopefully this is the only time you’ll plant asparagus. How well you prepare the bed determines the vigor of your asparagus patch for years to come.
Space plants 12 to 18 inches apart. In autumn, prepare the soil by mixing in several inches of organic matter (think compost or aged leaves) with the native soil in each row. Have your soil tested and amend it with lime if the pH is below 6.0 to 6.5. Add any other nutrients as recommended on test results. Mulch for the winter, or grow a cool season cover crop that can be turned under before planting in spring.
In spring after danger of frost has passed, dig a depression 6 to 8 inches deep running the length of the row, mounding the amended soil on each side for later use. Set seedlings into lowest part of the depression, planting about 2 inches deeper than they were originally growing. Space plants 12 to 18 inches apart.
As plants grow taller, rake a little of the soil on the edge of the row into the depression where plants are growing. Soon the bed will be level. Mulch to prevent weeds.
Then all you need to do is be patient. The ideal is to wait at least 2 seasons and probably 3 before harvesting. It may be hard to resist tasting the first spears to emerge, but go easy on the plants until they mature. You’ll be rewarded in the long run!