Mary Washington - Asparagus Seeds

Start asparagus seed indoors about 10–14 weeks before the expected last spring frost, or sow outdoors once the soil has warmed and can be kept evenly moist. Seed-grown plants take longer to reach harvest size than purchased crowns, but they establish well when given steady care.

Transplant seedlings after the danger of severe frost has passed and the plants are sturdy enough to handle. Plant dormant crowns in early spring as soon as the soil can be worked. In mild climates, fall planting may also be possible where crowns have time to root before cold weather arrives.

Soak seeds in room-temperature water for several hours before sowing to help soften the seed coat. Plant about ½ inch deep in individual cells or small pots filled with moist seed-starting mix. Keep the soil warm and evenly moist; germination may take two to four weeks.

Provide strong light once seedlings emerge. Grow them on until they are well rooted, then harden them gradually before transplanting. Space plants about 12–18 inches apart in rows 4–5 feet apart.

For crown planting, open a trench roughly 6–8 inches deep. Set crowns on small mounds of soil with the roots spread outward, then cover with a few inches of soil. Fill the trench gradually as the shoots grow until the bed is level.

Choose a permanent site in full sun with deep, well-drained soil. Because asparagus remains in place for many years, prepare the bed thoroughly before planting by removing perennial weeds and working in finished compost.

Keep young plantings evenly moist through their first seasons while the crowns become established. Mulch to conserve moisture, limit weeds, and protect the soil surface. Weed carefully, since asparagus roots are shallow near the crown and can be damaged by deep cultivation.

After harvest ends, allow the shoots to grow into tall, fernlike stems. These ferns feed the crown and build the reserves needed for the following spring. Leave them standing until they yellow naturally, then cut them near the ground after they are fully dormant.

Do not harvest during the first year after planting. Seed-grown plants may need two full seasons of growth before light picking begins. During the first harvest season, gather spears for only a short period, then allow the remaining shoots to fern out.

Cut or snap spears when they are about 6–8 inches tall and before the tips begin to loosen. Harvest every day or two during active growth. Established beds can usually be picked for several weeks each spring, but stop when new spears become noticeably thinner than a pencil.

Asparagus provides fiber, folate, vitamin K, vitamin C, and potassium. It also contains carotenoids, flavonoids, and other naturally occurring plant compounds.

Use the spears steamed, roasted, grilled, sautéed, pickled, or added to soups, omelets, pasta, and grain dishes. Freshly harvested asparagus is especially tender and sweet when cooked soon after picking.

Asparagus beetles may feed on spears and foliage, while cutworms and slugs can damage young shoots. Inspect plants regularly, handpick adults and larvae where practical, and remove heavily infested plant debris.

Good airflow, clean beds, crop rotation before establishment, and well-drained soil help reduce rust, crown rot, and other disease problems. Avoid planting asparagus in low, wet ground, and do not cover the crowns so deeply that water collects around them.

Asparagus is an insect-pollinated perennial, and most varieties produce separate male and female plants. Female plants form round berries after flowering, while male plants produce pollen but no fruit.

Save seed from several healthy, vigorous female plants and keep them growing near enough male plants for good pollination. Grow only one asparagus variety for seed or provide generous isolation from other flowering asparagus plantings.

Allow the berries to ripen fully until they turn red. Wear gloves when handling them, since the berries should not be eaten. Crush the ripe fruit in water, separate the seed from the pulp, rinse thoroughly, and spread the cleaned seed to dry in a warm, airy place out of direct sun. Store fully dry seed in a labeled container in a cool, dark location.

• Choose the planting site carefully because asparagus is difficult to move later.
• Remove perennial weeds before planting the bed.
• Do not harvest young plants too soon.
• Let the ferns grow fully after harvest.
• Add compost and mulch each year without burying the crowns deeply.