Asparagus may be one of the most costly vegetables at the supermarket. However, this perennial vegetable may be one of the easiest to grow. Perennials are plants that live for many growing seasons. Perennial plants dieback in the winter and come back in the spring from the same root system. Asparagus plants will produce for 20 years, if not longer, providing the tender green spears every spring. It will take 2 – 3 years before the asparagus reaches full production. So, before you begin planting, choose the perfect site and prepare the bed well, it’s going to be there a long time.
There are several varieties of Asparagus officinalis altilis to choose from. Most have heard of Mary Washington. This is an older variety that has been a standard for many decades. It is a female variety. No, you do not need more than one variety, and it doesn’t matter if you have male or female plants. I really like some of the newer male hybrids such as Jersey Knight and Jersey Gem. Often, they produce more spears. The male plants do not produce seeds which can lead to seedling asparagus that may become a nuisance in the garden. There is also a purple cultivar of asparagus that grows well here, Purple Passion. Once cooked, it will turn green. Green, purple, blue, or yellow, fresh asparagus spears from the garden is hard to beat.
Dormant asparagus crowns can be planted as early January through March in Alabama. Use one year old crowns or plants as it takes one to two years longer to produce asparagus from seed. Purchase the plants from a garden store, nursery or through a seed catalog. Set crowns out in the Spring. The most common planting method is to dig a trench 10 to 12 inches deep and just as wide. Incorporate rotted manure or compost in the bottom of the trench before setting the crowns into the trench.
Set plants in the sun – Asparagus, like most vegetable plants, needs full sun. Full sun means at least 6 – 8 hours of uninterrupted sunlight every day. Asparagus beds planted near trees may receive full sun at the time the bed was prepared. Remember the trees will grow and years from now, the bed may become shaded. Plan accordingly. Plant asparagus along the perimeter of the vegetable garden so it will not be in the way of garden equipment. .
Soil- Asparagus prefers a high organic soil. Most soils in Alabama will have to be amended to grow asparagus successfully.
Fertility– Asparagus has medium to high fertility requirements. A soil test is the best way to calculate fertilizer requirements. Before planting, incorporate 1 pound of actual nitrogen into the planting bed. Another pound of actual nitrogen can be applied after harvest. One pound of actual nitrogen per 1000 square feet is equal to approximately ¾ lb of ammonium nitrate per 100 feet of row.
pH – 6.0 to 7.0
Moisture – Asparagus requires a moist soil – about 1 to 2 inches of water per week (more on a sandy soil; less for a clay soil).
Spacing and Depth
Set the crowns 12 inches apart in the trench. Asparagus beds or trenches should be at least 3 feet apart. Place the crowns on top of a small amount of loose soil in the bottom of the trench. Make sure the roots of the crown are spread out over the soil. The crowns should be covered with 2- 3 inches of soil. The asparagus will grow up and through this soil. When it does pull the soil in around the crowns and cover them up with a couple of inches of soil. Again, the asparagus plants will grow through. Cover them again and repeat until the trench is filled. Take care of the plants. Asparagus is a fern like plant. Let it grow until frost turns the asparagus plant brown. At that time you can cut down the brown ferns. Early the next year, use your soil test results to fertilize the plants.
Harvesting and Storage
Early in the year, you will see the asparagus spears start to poke through the ground. But, be patient. Do not harvest any asparagus the first year, much like blueberries. Harvesting too much too early will result in a week plant. The second year, you will be able to enjoy about 6 weeks of harvest…and maybe 8 weeks the next year. Harvest the spears daily when they are 5 to 7 inches tall. Snap off above the soil line. Harvest in the early morning and use or refrigerate immediately.
Asparagus is low in calories and carbohydrates, and compared to other vegetables it is relatively rich in protein. Asparagus is an excellent source of potassium, vitamin K, folic acid, vitamins C and A, riboflavin, thiamine, and vitamin B6. It is also a very good source of dietary fiber, niacin, phosphorus, protein, and iron.
by Dani Carroll