Can Asparagus Be Grown in Containers?

Choosing a Container

• Use as big a container as you can manage -- at least 20 inches deep and with a large enough diameter to allow 20 inches of horizontal space for each plant. The more space the plants have, the happier they'll be. The container also needs holes in the bottom for drainage. Plant asparagus crowns on a small mound of compost in the middle of a hole 6 to 8 inches deep and cover the roots with soil; add soil to the hole as the shoots grow until the hole is full.

Location

• Since a large container will be difficult to move once it's planted, choose the best place for your asparagus pot from the start. Asparagus needs plenty of sun, so position your container where it will get at least eight hours of sun each day. Because asparagus does not transplant well, consider the container its permanent home and don't count on being able to move it to a garden bed later.

Watering and Fertilizing

• Keep the container's soil moist, but don't over water. If you allow the top layer of soil to dry out before you water, you'll reduce the risk of the plants' roots rotting from excess moisture. Add a superphosphate 0-20-0 fertilizer to the hole when you initially plant the crowns, and fertilize each spring with a balanced fertilizer or organic compost.

Harvesting

• Don't harvest container-grown asparagus until the third year after you plant the crowns. During the first two seasons, allow the plants to produce stems and leaves, and cut them back to ground level in the fall. Harvest stems in the third season, breaking them off just below the level of the soil, but stop harvesting when the new stems the plants produce are small, about 3/8-inch in diameter, so that the plants can gather strength for the next season.

Longevity

• When planted in the ground, asparagus makes use of all the space available; in loose soils, the plants' roots may grow 10 feet deep. Robust plants in garden beds can continue to produce well for more than 20 years. Container-grown plants don't have room to establish themselves as well, and it's unlikely that they will continue to produce for more than three or four years.