Asparagus

Male vs. Female

There are male and female asparagus plants. Since male plants can be three to five times more productive than female plants, choose a male plant whenever possible. Popular male hybrids include ‘Jersey Giant’, ‘Jersey Supreme’, ‘Jersey Knight’, and ‘Jersey King’.

Asparagus Care Must-Knows

Asparagus grows best in full sun and moist, well-drained soil. Select the location carefully as your asparagus patch will last for many years. Look beyond the traditional vegetable garden when selecting a location for asparagus. A perennial garden might be a great spot for asparagus, as would a shrub border.

Plant asparagus as soon as the soil can be worked in spring. Most commonly started from established crowns purchased at your local garden center or through a mail order source, asparagus can also be started from seed. If starting from seed, plan to harvest your first crop about 4 years after planting. When started from crowns, asparagus is ready for harvest 2 to 3 years after planting.

To plant asparagus, place crowns in a trench 12 to 18 inches wide and 6 inches deep. Space the crowns 9 to 12 inches apart in the trench. Cover the crowns with 2 inches of soil, and water well.

Regular fertilization encourages a prolific crop of asparagus. For 3 years after planting, fertilize asparagus plantings in early spring. After 3 years, transition to fertilizing plants right after the last harvest in June or July. Apply a balanced fertilizer, such as 10-10-10 at the rate of 1 to 1.5 pounds per 100 square feet.

It’s important to control weeds in asparagus beds because they can reduce your harvest. In spring and during the harvest season, pull and hoe weeds to remove them. Some gardeners apply large amounts of table salt to asparagus beds to control weeds. This is generally ineffective and not recommended. Adding a 3-4 inch thick layer of mulch is a better route to go to prevent new weeds from sprouting.

After asparagus stems are cut to ground level at the end of the harvest, the plants will send up new shoots. All the shoots expand to form tall, ferny seed heads through the growing season. Cut them back in late fall or winter after they turn brown.

Harvest Tips

Allow asparagus to grow without harvesting the year it is planted. In the second year, harvest spears that are ½ inch in diameter, but only for 2 weeks. Cut or break off 7- to 9-inch-long spears with tightly closed tips. In subsequent years, harvest for 5-8 weeks, then allow the shoots to develop into ferny growth to build up the roots for the following year’s crop.

More Varieties of Asparagus

‘Jersey Giant’ asparagus

This is the most widely grown variety. It is more disease-resistant and more productive than older varieties. Its green spears with purplish tips are all male so it wastes no energy on flowering and seed production.

‘Purple Passion’ asparagus

‘Purple Passion’ bears purple spears that are sweeter than green ones, but the yield is less and spears turn green when cooked.

‘UC 157’ asparagus

This type is a great choice for warm-winter regions. Developed in California, it’s better suited to hot, dry conditions.