Conovers Colossal Asparagus spears with some chopped on a white background.
Cut and whole Conovers Colossal Asparagus with coins and props to show size on white.
Grilled Conovers Colossal Asparagus in a tin plate with a vintage Springfield Newsleader.
Overhead view of grilled Conovers Colossal Asparagus lined up on a blue plate on black.
Freshly picked Conovers Colossal Asparagus in a wood basket on a wooden cutting board.
Conovers Colossal Asparagus spears with some chopped on a white background.
Cut and whole Conovers Colossal Asparagus with coins and props to show size on white.
Grilled Conovers Colossal Asparagus in a tin plate with a vintage Springfield Newsleader.
Overhead view of grilled Conovers Colossal Asparagus lined up on a blue plate on black.
Freshly picked Conovers Colossal Asparagus in a wood basket on a wooden cutting board.

Asparagus Seeds,
Conovers Colossal

4.79 ReviewsSKU: #AS103Min. seed count: 40
Price
Regular price $3.50
Regular price $0.00 Sale price $3.50
Save $-3.50
/
Shipping calculated at checkout.
Description

(Asparagus officinalis). It is no wonder that Conover’s Colossal was developed specifically for market farmers: this variety is hearty, vigorous, and sure to please with its buttery, tender spears. This 19th century heirloom is still beloved by market farmers and home gardeners today. Produce merchant S.B. Conover of New York City developed it in the 1860s, selecting for the superior market qualities of massive spears and super high yields. This superb variety has been praised by the likes of famous 19th century market gardener Peter Henderson, as well as the Royal Horticultural Society. Spears can reach one inch thick and remain supremely soft and juicy. This heirloom asparagus is a true culinary delight and not to be missed.

Growing Tips: Conover’s Colossal is a vigorous heirloom asparagus variety prized for its extra-large, tender spears and excellent cold hardiness. Though it requires patience to establish, it can produce reliable, delicious harvests for 15+ years once mature.

Plant Details

Botanical Name
Asparagus officinalis
Life Cycle
Perennial in zones 3–8
Sun Requirement
Full sun
Days to Germinate
10–21
Days to Maturity
730
Planting Depth
½ in. (seeds); 6–8 in. (crowns)
Plant Spacing
12–18 in.
Ideal Temperature
60–85°F
Frost Hardy
Yes

When to Grow

Start seeds indoors 10 to12 weeks before your last spring frost, or sow directly into well-prepared garden beds in early spring. Asparagus benefits from a long season to establish deep roots before winter dormancy. If you’re not sure how to find your first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

How to Sow and Plant

Sow seeds ½ inch deep in seed-starting mix indoors or outdoors in rich, loose soil. Once seedlings are 10 to 12 weeks old, transplant into a trench 6 to 8 inches deep, spacing plants 12 to 18 inches apart.

How to Grow

Keep young plants weed-free and well-watered during their first two seasons. Avoid harvesting spears in the first year. In year two, harvest lightly, then allow ferns to grow and recharge roots for next spring’s crop.

How to Save Seeds

  • Allow some ferns to mature and flower in year two or later
  • Collect red berries after they ripen in late summer or fall
  • Remove seeds from berries and rinse thoroughly
  • Dry seeds completely before storing
  • Store in a labeled, airtight container in a cool, dry place

FAQ

Can I harvest Conover’s Colossal asparagus the first year?

No. Seed-grown asparagus needs two full seasons to build the crown a purchased crown already has, so do not cut in the first or second year. Take a light harvest of 2 to 3 weeks of spears in the third year, and harvest fully from the fourth year onward.

How long does Conover’s Colossal asparagus live?

When properly cared for, a single planting can produce high-quality spears each spring for 15 to 20 years. Annual weeding, fertilizing, and allowing ferns to regrow are key to longevity.

Is it better to start from seed or crowns?

Seeds are more cost-effective and disease-resistant but take longer to mature. Crowns provide a head start, but seed-grown asparagus often yields stronger, longer-lived plants in the long run.

Browse our full range of asparagus seeds.
FREE SHIPPING IN THE U.S.A.
Alternate domestic shipping options available at checkout.
You may also like