Prized for their edible stems or spears, asparagus plants are one of the few vegetables that grow perennially, and are harvested in the spring—long before other crops have even sprouted. But while most gardeners grow green, white, or purple asparagus from annual transplants or “crowns,” you can save money and make your garden more self-sufficient by growing asparagus from seed.

In this guide, we’ll walk you through the basics of when and how to plant asparagus seeds and teach you how to transplant, care for, and harvest your asparagus.

When and where to plant asparagus seeds

The main difference between growing asparagus from seed versus asparagus tops is that you will have to wait another year to harvest the asparagus grown from seed. But the good news is that asparagus seeds are easy to grow and can be started indoors or directly in the garden.

Asparagus seeds are usually planted in pots or trays in early spring – about 10 to 12 weeks before the last frost. However, asparagus seed can also be direct sown in underground or raised gardens after the last spring frost.

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How to plant asparagus seeds

Many growers keep asparagus plants in nurseries in their first year of growth to avoid competition with weeds and provide the young plants with the right conditions for strong root development. Whether you plan to plant asparagus seeds indoors or outdoors, here’s how to make a simple nursery bed and sow asparagus seeds.

Preparing a child’s bed

To get started, choose a growing location that receives at least seven hours of direct sunlight per day and follow these tips to create a nursery bed.

1. Loosen the soil to a depth of 10 to 12 inches and remove all rocks and weeds.
2. Test the soil and add soil amendments (if necessary). Asparagus grows best in rich, well-draining soil with a pH between 6.5 and 7.0.
3. Before planting asparagus seeds or transplanting, mix a few inches of compost or aged manure into the top few inches of soil.

Indoor Sowing

Planting asparagus seeds indoors in early spring takes a little more time, but gives you more control over the growing conditions and health of the young seedlings.

1. Soak the seeds in water for a few hours before planting. While the seeds are soaking, fill seed starter trays or containers with pre-moistened seed starting mix.
2. Sow one to two asparagus seeds per pot or seedling cell, cover the seeds with ½ inch of seed starting mix and add a moist dome.
3. Place the seedlings under a grow light and on top of a seedling heating mat and set at 75 to 85 degrees Fahrenheit. Water regularly until the seeds sprout. This may take a few weeks, so please be patient!
4. Once the seedlings have germinated, remove the wet dome and heat mat. Continue to water regularly to keep the soil moist but not soggy.
5. When the seedlings are a few inches tall, leave one seedling per pot or planting cell and thin out the rest.
6. Transplant indoor seedlings outside when they are a few inches tall and the danger of frost has passed.

Sowing outdoors

For easier access, plant asparagus seeds outdoors in prepared beds after the last spring frost.

1. Plant seeds ½ inch deep, 2 to 3 inches apart, in rows about 1 foot apart. If possible, soak asparagus seeds in water before planting to speed germination.
2. Water frequently to keep the soil moist and weed regularly to prevent weed competition. Asparagus seeds should germinate in a few weeks.
3. When the seedlings emerge and are several inches tall, spread a light layer of straw around the soil line to block weeds.

Transplanting Seeds

Seedlings started outdoors will not need to be repotted during the first year of growth. However, indoor seedlings should be transplanted outside after the last spring frost.

1. Harden off the seedlings for one to two weeks by moving them outdoors during the day and indoors at night. Gradually increase the time the seedlings are outside and the amount of sun they are exposed to until the plants can tolerate full sun.
2. Transplant the asparagus seedlings in rows spaced about 1 foot apart in a prepared nursery bed. Set each plant back about 1 foot from its neighbors and bury the seedlings deep enough to cover their roots.
3. Water well and apply a light layer of straw mulch.

How to care for asparagus

After a year of growth in the nursery, asparagus crowns can be transplanted into your main garden in early spring. Before planting, loosen the soil and add amendments, then plant the old-year asparagus tops in 6-inch-deep trenches 2 to 3 feet apart. Spread the plant roots, space individual plants 2 feet apart, cover the roots with 2 inches of soil, and follow these quick care tips to maintain a healthy asparagus crop.

• Mounding. Add more soil over the top of the asparagus every few weeks until the tops are covered with a small mound of soil. In winter, apply a 4- to 6-inch layer of straw over the roots for insulation.
• Watering. Provide asparagus plants with about 1 inch of water per week.
• Fertilization. Fertilize asparagus once or twice a year in early spring and after harvest with a well-balanced fertilizer or compost.
• Weeding. Asparagus does not compete well with weeds and the beds need to be weeded regularly.
• Circumcision. Do not cut the fern-like fronds from asparagus plants until they die back in the fall. Those leaves are the fuel for the next year’s asparagus growth.

Harvesting asparagus

If you start an asparagus plant from seed, you will have to wait at least three years to harvest the edible spears. Asparagus season starts in the spring and runs through the end of June, but you should only harvest spears for two to three weeks during the first harvest season. Harvest the spears when they are as wide as your finger and about 6 to 8 inches long, and use a sharp knife to cut the spears at the soil line to limit damage to the plants.