When to Grow Asparagus in a Container
There is no getting around the fact that asparagus is best grown in a large, deep garden bed, whether in the ground or in a raised bed on top of the ground. However, there are times when this simply is not possible. For example:
- You have a very small yard or limited garden space for this crop.
- You have no garden space, only a porch, deck, or balcony.
In these cases, growing asparagus in a container may be your only choice if you want to produce this vegetable at home.
Choosing a Container and a Variety
If you are planting asparagus in a container, starting with crowns is best because your crop will already be at a disadvantage and crowns will maximize your chances of success. Choose a high-yeilding asparagus variety with all-male or predominately male plants like Jersey Supreme. This will also give you an edge on getting as much from you asparagus container garden as possible.
Expect a three to five year lifespan for the plants. While starting from crowns is the fastest way of harvesting a crop, even in a container, you should not pick the spears for the first two seasons after planting in order to allow the root system to develop as fully as possible.
Use as large a container as possible and at least 30 gallons (113 liters) in size. The container can be made of terra cotta, wood, or plastic as long as it has adequate drainage holes. A large plastic tote can be used by drilling approximately 20 ¼ inch (.6cm) holes in the bottom to allow for drainage. Make sure the container is at least 18 inches (46cm) deep and fill it with a high-quality potting soil.
Caring for Asparagus in Containers
Asparagus prefers full sun, so situate the container where it will receive at least 8 hours of direct sun during the growing season. If you live in an area with hot summers, you may need to protect the outside of the container by placing straw around it to keep it from heating up too much during summer days.
Plants grown in containers can dry out easily in hot weather, so water frequently, keeping the soil moist but not soggy starting in the spring and continuing throughout the summer. Care for asparagus plants in containers in the same way as plants growing in the ground by fertilizing them in spring and cutting back the ferns in winter.