Things to know about Asparagus:
- USDA Hardiness Zones: 3 and warmer
- Sun exposure: Full Sun, Part Sun
- Bloom time: Harvest in April, May
- Perennial: Continues each year
- Soil type: Sandy, loamy
- Varieties: Mary Washington (rust resistant); Waltham Washington (rust resistant); Heirloom: Jersey Knight
Asparagus (Asparagus officinalis) belongs to the lily family and can be found growing on country roads along road ditches. It grows wild on the shorelines and riverbanks in many parts of Europe and on the prairies of Russia. Both the Romans and Greeks enjoyed this succulent vegetable and transplanted the wild plants to their cultivated gardens.
Where to Grow Asparagus?
A perennial vegetable, asparagus thrives anywhere in the continental United States except where summers are long and humid. Proper soil preparation before planting and good summer maintenance will keep asparagus yielding for a minimum of 10 years and possibly as long as 20 years.
Give it a specific area for planting because it is long-lived and permanent. It is often planted near rhubarb, another long-lived garden perennial vegetable, treated as a fruit.
A sandy, well-drained loam is best for asparagus supplemented with well-rotted manure and compost. The pH should be 6.5 to 6.8 and asparagus will tolerate slightly alkaline soils up to 7.5.
Average garden soil, however, will support a good asparagus crop, provided it drains well. Rocky soil hampers the development of straight spears.
Prepare the soil to a depth of 1 foot, a week to 10 days before planting, adding the rotted manure and compost and working it in well. Add a fertilizer application of 4 pounds of 5-10-10 per 100 square feet, or generous quantities of bone meal or ground phosphate rock and wood ash. Good neighbors for asparagus are tomatoes, basil, parsley and nasturtiums.
When to Plant Asparagus?
As soon as the ground can be worked in the spring when all frost danger has passed, it’s time to plant asparagus. Buy one-year-old, two-year-old or three-year-old plants, or “crowns,” from a garden supply center or a seed catalog. They should have tight compact buds with masses of flexible dangling roots.
Plants are set out in trenches, dug to a depth of 6 to 8 inches and spaced 4 feet apart, in the prepared bed. Mound the soil to the side of each trench because it will be used to backfill as the asparagus grows. Planting asparagus crowns in the base of the trench, with 18-inches between plants, and cover with about 2-inches of soil is best.
As the asparagus tips grow during the summer, the trenches will be filled in gradually until they are completely filled by the end of summer. Asparagus plants have a tendency to “rise” as they grow mature, therefore, the need for the trenching method of planting. It works. This procedure can also be done in early fall.
How to Grow Asparagus?
Asparagus roots grow horizontally rather than vertically (down) and in years to come will produce a thick mat of roots and underground shoots. The first year after planting the spears will be thin and spindly. As they mature they develop into tall, lovely ferny branchlets at the top.
The true asparagus leaves are tucked away into the top and side scales. They are immature leaves and are cut off the stem when cleaning for cooking as they might contain grit. The plant is dioecious, having tiny male and female flowers that have a small berry for fruit. Birds love these seeds and “plant” them all over for more wild asparagus to grow.
The male plants produce more spears so it’s advisable to purchase them rather than female having less spears and making seed. The ferny top collects the sun for producing food for the shoots below the same as bulb foliage renews a bulb underground for next spring’s flowers. For this reason, do not cut off the top growth. Let it turn brown in the fall and wither naturally and fall off. It can be cut off in late fall and used as mulch over the winter.
Weeds are a big problem for asparagus offering much competition for the developing shoots. An untidy weedy asparagus patch can develop quickly if left unattended. Frequent light cultivation is a good preventive. Light mulching is another.
The first cultivation should be in early spring before the spears appear above ground. Now is a good time to add a light fertilizer such as compost and well-rotted manure or 1/2-ounce nitrate of soda, to each plant. Do not put the manure too close to the center of the shoots, but outside. Continue hoe cultivating until the tops have grown thick and high.
Watering is important any time there is a lack of rainfall during the growing season. Do not just sprinkle water; water deeply and thoroughly. After harvest is complete, feed the asparagus with a well-balanced fertilizer to encourage a generous crop of succulent spears for next spring. Full harvest will be available the third year.
TIP: Do not pick spears to eat the first year. The plant is gaining energy. Pick sparsely the second year. After picking, always leave a few spears on each plant to fern out and gain energy for the roots.
The juicy and tenderness of asparagus depends on the quality of the soil, the quickness of shoot development in the spring, and adequate moisture for the soil. Cutting may last 4 to 6 weeks starting in April, depending on rain and sunshine. It also depends on how well the soil has been managed. Asparagus is best when just about 6 inches tall and tight at the tip, not starting to spread into little branches to fern out.
At the height of the growing season, there may be fresh spears each day. Stop harvesting when the spears start to look thin and spindly and when the heat of summer arrives. You can cut off the spears with an asparagus knife at ground level being careful not to go into the soil and damage the roots. or snap a spear where tender meets tough. The woody bottoms are not edible.
Asparagus is similar to corn. The quality deteriorates quickly. Pick it just before it is to be cooked. If unable to do this, refrigerate it promptly in a paper bag, not plastic. Plastic causes condensation and rot. Or put into a container with a snug closure.
Pests: Asparagus beetle: Handpick them off
Diseases: Rust has been eliminated by the development of rust-resistant varieties
Clean under cool running water. Cut off any bad spots. Cut into pieces or leave whole. Pan sauté in a little water with butter and a little lemon juice and salt until still green and fork crisp tender. If the asparagus turns yellow, it has cooked too long and will be mushy. Cook 6 to 8 minutes and it will hold its beautiful green color. Serve with broiled salmon and rice pilaf. Delicious. The flavor is nothing like store bought.
Asparagus can be used raw in salads. Only use the most tender top part of the spears. Use the bottoms for cooking or creamed asparagus soup.