Asparagus is a perennial plant. Plant asparagus where it can grow undisturbed and be productive for 15 to 20 years.
Asparagus is one of the earliest crops to come to harvest in spring. The edible parts of the asparagus plant are young, tender, green shoots, called spears. Spears are young leaf stalks—eaten leafless—that grow from the plant’s roots in early spring. If not harvested leafless, the spears will become tall ferny-leafed plants.
Asparagus can be grown from seeds or root divisions called “crowns”.
Asparagus spears are commonly not harvested in the first year after planting. It’s best to allow plants to develop a strong root system before you begin harvesting spears in the spring of the second or third year after planting.
Grown from seed, the first harvest will come during the third year. Started from one-year-old roots or crowns, the first crop will come the second year after planting.
Asparagus Sowing and Planting Tips
- Grow asparagus from seed or root divisions also called crowns.
- Seed can be started indoors 8 to 6 weeks before the last frost in spring; plants can be transplanted to the garden when they are well established, 2 or 3 weeks after the last frost in spring.
- Sow seed ¼ to ½ inch deep (6-13 mm); pot up young plants until they are well established before transplanting to the garden. Set transplants in a trench 6 to 8 inches (15-20 cm) deep; the trench will be slowly and naturally fill in as the plant grows over the course of the first two years.
- In the spring of the second year, cover all but the tops of spear growing tips to help plants establish strong roots.
- If you start plants from crowns, set out crowns in late winter or early spring when the soil can be worked—usually about 2 weeks before the last frost in spring.
- Plant crowns in trenches 8 to 10 inches (20-25 cm) deep and 12 inches (30 cm) wide.
- Set crowns at the bottom of the trench then cover with 2 inches (5 cm) of soil.
- Space crowns and plants 8 inches (20 cm) apart for slender spears to 14 inches (36 m) apart for thick spears.
- Space trenches 4 feet (1.5 m) apart.
- Grow asparagus in loose, aged-manure- or aged-compost-enriched soil.
- After shoots emerge in spring and begin to grow, gradually fill in the remainder of the trench with soil, but never fully cover the growing tips.
- Fertilize with fish emulsion or a soluble complete fertilizer at half strength.
- Add aged compost to planting beds in advance of planting.
- Asparagus prefers a soil pH range of 6.5 to 7.0.
- Grow asparagus in full sun for best yield.
- Plant asparagus in a dedicated bed; plants will live up to 15 years.
Interplanting: Plant in a dedicated bed; asparagus plants can live and be productive for up to 15 to 20 years.
Asparagus Planting Calendar
- From seed: start seed indoors 8 to 6 weeks before the last frost in spring; plants can be transplanted to the garden when they are well established, 2 or 3 weeks after the last frost in spring.
- From crowns: set out crowns in late winter or early spring when the soil can be worked—usually about 2 weeks before the last frost in spring.
Asparagus Recommended Varieties
- ‘Martha Washington’ and ‘Mary Washington’ are old-time varieties.
- All-male varieties produce larger spears; they include ‘Jersey Giant’, ‘Jersey Knight’, and ‘Greenwich.’
Botanical Name: Asparagus officinalis
Asparagus is a member of the Asparagaceae (Liliaceae) family
More tips: How to Grow Asparagus.