How to Plant Asparagus:
Crowns, Beds, and Harvest Guide
Learning how to plant asparagus is one of the best long-term investments you can make in a vegetable garden. A well-planted bed can produce fresh spears every spring for fifteen to twenty years or more. No other vegetable gives that kind of return on a single afternoon of work.
★ SaveThe catch is patience: asparagus needs two to three years to settle in before you can harvest a full crop. Get the planting right at the start, and that patience is repaid many times over. This guide covers crowns or seed, the best varieties, the permanent bed, the trench method, and the waiting years that trip up so many first-time growers.
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Asparagus at a Glance
| What | Recommendation |
|---|---|
| Start from | Crowns (one-year-old roots); seed adds a year |
| Best varieties | All-male hybrids like Jersey Knight, Jersey Giant, and Jersey Supreme |
| Sun | Full sun, 6 to 8 hours a day |
| Soil | Deep, well-drained, rich in compost; pH 6.5 to 7.5 |
| When to plant | Early spring, when soil reaches about 50 to 55 degrees |
| Trench | 12 to 18 inches wide, 6 to 8 inches deep |
| Spacing | Crowns 12 to 18 inches apart; rows 3 to 5 feet apart |
| First harvest | Light harvest in year 2; full 6 to 8 weeks from year 3 |
| How long a bed lasts | 15 to 20 years or more |
According to Utah State University Extension, asparagus thrives in full sun with fertile, well-drained soil rich in organic matter, and a well-prepared bed can stay productive for twenty years or longer with only modest yearly care.
Crowns or Seed? Choosing Your Starting Point
★ SaveCrowns are one-year-old asparagus roots, sold dormant and ready to plant. They are by far the most popular way to start, because they save a whole year: expect a small, careful harvest in year two and a full harvest by year three. Crowns are sold by mail order and at garden centers in late winter and early spring, usually in bundles of 10 or 25. Plant them as soon as you can, keep them slightly moist until then, and never let them dry out.
Seed costs less, and some gardeners find seed-grown plants more vigorous in the long run, but it adds a year. Start seed indoors 12 to 14 weeks before your last frost, soak it for a few hours first, and set seedlings out once frost danger has passed.
| Factor | Crowns | Seed |
|---|---|---|
| First light harvest | 2 years | 3 to 4 years |
| Full harvest | 3 years | 4 to 5 years |
| Cost | Higher per plant | Lower per plant |
| Where to buy | Garden centers and mail order, late winter and spring | Seed catalogs, year-round |
| Best for | Most home gardeners; faster results | Patient gardeners; big plantings on a budget |
For almost all home gardeners, crowns are the practical choice, so the rest of this guide focuses on how to plant asparagus crowns.
Choosing an Asparagus Variety
★ SaveChoose an all-male variety. Whichever you pick, the steps for how to plant asparagus are the same. Female plants make pretty red berries, but the berries take energy away from the spears. All-male varieties were bred to put that energy into thicker, more plentiful spears.
| Variety | Type | Why Grow It |
|---|---|---|
| Jersey Knight | All-male hybrid | The top pick for beginners: vigorous, disease resistant, productive, and adaptable |
| Jersey Giant | All-male hybrid | Large spears and good cold tolerance |
| Jersey Supreme | All-male hybrid | Early and very productive |
| Purple Passion | Male and female plants | Sweet, tender purple spears; less productive |
| Mary Washington | Older open-pollinated | A classic, now outproduced by the all-male hybrids |
Choosing the Right Site for Asparagus
★ SaveThe site is the first big decision in how to plant asparagus. Choose carefully, because the bed will stay put for twenty years. Asparagus isn't a crop you move or rotate like lettuce or beans.
- Full sun: six to eight hours of direct sun a day.
- Out of the way: the ferny summer foliage grows 4 to 5 feet tall, so put the bed at the edge or back of the garden, where it won't shade shorter crops or get tilled.
- Good drainage: asparagus roots rot in soggy soil. If your soil is heavy clay or stays wet, build a raised bed just for asparagus. It's worth getting right the first time.
Preparing the Asparagus Bed Soil
★ SaveThorough soil preparation is the most important step in how to plant asparagus. You won't be able to dig the bed deeply again for two decades, so this is your once-in-a-generation chance to get the soil right.
- Test the pH. Asparagus likes 6.5 to 7.5. Add lime now if your soil is more acidic; it's much harder to fix later.
- Add compost and aged manure, plus a phosphorus-rich amendment like bone meal for strong roots.
- Loosen the soil 12 to 15 inches deep, deeper than for almost any other vegetable, and remove stones and break up hard layers.
See our guides to vegetable garden soil and raised bed gardens.
How to Plant Asparagus Crowns Step by Step
★ SaveThis is the trench method recommended by university extension services, and the most reliable way to plant a long-lived bed.
- Dig a trench 12 to 18 inches wide and 6 to 8 inches deep. Go shallower (6 inches) in heavy soil, and deeper (8 inches) in sandy soil or cold climates. Space rows 3 to 5 feet apart.
- Make a ridge. Build a 2- to 3-inch ridge of soil down the center of the trench floor.
- Soak dry crowns briefly in lukewarm water if they dried out in shipping.
- Set each crown on the ridge, roots spread out like the spokes of a wheel and the pointed bud facing up. Space crowns 12 to 18 inches apart.
- Cover with 2 to 3 inches of soil, leaving the rest of the trench open for now.
- Fill in slowly. Every few weeks, as shoots come up, add more soil, always leaving the newest tips above the surface. By mid to late summer the trench should be level with the bed.
| Element | Recommendation |
|---|---|
| Trench width | 12 to 18 inches |
| Trench depth | 6 to 8 inches (shallower in heavy soil, deeper in sandy soil or cold climates) |
| Spacing between crowns | 12 to 18 inches |
| Spacing between rows | 3 to 5 feet |
| First soil covering | 2 to 3 inches over the crown |
| Best planting time | Early spring, soil about 50 to 55 degrees |
When to Plant Asparagus
★ SavePlant in early spring, once the soil can be worked and has warmed to about 50 to 55 degrees, before the crowns start to sprout. In most of the US that's between late March and mid-May, earlier in the south and later in the north. Our free zone finder shows your frost dates.
Don't plant into cold, soggy soil. Crowns can rot before they get started. If a wet spell delays planting after your crowns arrive, keep them cool with the roots covered in slightly damp peat moss or sand.
The Waiting Years: Why Asparagus Takes Time
★ SaveThis is the part that surprises first-time growers. In the first year, the plant needs every spear to grow ferny foliage and build a bigger root system. Cutting spears too early weakens the plant and can set it back for years.
| Year After Planting Crowns | Harvest Guidance |
|---|---|
| Year 1 | No harvest. Let all spears grow into foliage to build the roots. |
| Year 2 | Very light harvest, 2 to 3 weeks at most. Cut only the thickest spears. |
| Year 3 | Harvest for 6 to 8 weeks. The bed is now established. |
| Year 4 on | The standard 6 to 8 week harvest every spring for the life of the bed. |
This slow start is the single most important part of how to plant asparagus well. It's the difference between a bed that produces for twenty years and one that never recovers from early overharvesting.
Caring for Your Asparagus Bed
★ Save- Keep it weed-free, especially the first two years. Young asparagus competes poorly with weeds. A 3-inch layer of weed-free straw mulch keeps weeds down, holds moisture, and keeps the soil cool enough in spring to delay spears past a late frost.
- Water deeply the first season. Once established after two or three years, asparagus handles dry spells well and needs water mainly in long droughts.
- Feed after harvest. Use a balanced or phosphorus-rich fertilizer at planting, then a nitrogen-rich feed each year after the harvest ends to power the summer ferns. Side-dress with compost every year. See how to fertilize a vegetable garden.
| Season | Asparagus Bed Jobs |
|---|---|
| Early spring | Pull weeds, side-dress with compost, and plant new crowns |
| Mid to late spring | Harvest spears daily during the harvest window |
| After harvest | Stop cutting, feed with nitrogen, and let the ferns grow |
| Summer | Water in dry spells, weed, and watch for asparagus beetles |
| Fall | Cut down ferns once they turn yellow, clear them away, and mulch |
Harvesting Asparagus
★ Save- Pick spears 5 to 9 inches tall, snapping or cutting them at or just below the soil. Snapping by hand breaks the spear at its tender point and won't nick nearby buds the way a knife can.
- Harvest in the morning, when spears are crisp.
- Check daily. In warm weather, spears can grow several inches in a day and turn tough if left too long.
- Stop after 6 to 8 weeks. Let the rest grow into ferns. They look untidy, but they feed the crowns for next year. Leave them until they yellow in fall, then cut them down and clear them away to reduce pests and disease.
Have more than you can eat? See how to freeze vegetables.
Common Asparagus Problems
★ Save| Problem | Likely Cause | What to Do |
|---|---|---|
| Thin, spindly spears | Crowding, too little food, or harvesting too hard when young | Shorten the harvest for a season or two and feed with compost and balanced fertilizer |
| Chewed spears and ferns | Asparagus beetles and their grayish larvae | Hand pick in small beds; use insecticidal soap or spinosad in larger plantings |
| Crowns rot and plants die | Soggy, poorly drained soil | No cure; prevent it with good drainage or a raised bed |
| Slow, weak young bed | Weeds competing in the first two years | Mulch and hand weed through the establishment years |
Asparagus beetles: the common asparagus beetle is blue-black with cream spots and a reddish edge, and the spotted asparagus beetle is orange-red with black spots. Both feed on spears and ferns.
How to Plant Asparagus: Questions and Answers
★ SaveHow many asparagus crowns should I plant?
About 10 to 20 crowns per person who loves asparagus, since each established crown gives roughly half a pound of spears a year. A family of four might plant 40 to 60; a household that wants an occasional spring treat could be happy with 10 to 15.
Can I move an established asparagus bed?
Asparagus doesn't transplant well once established. Moving mature crowns usually sets them back for years, so choose the permanent spot the first time.
Why didn't my asparagus crowns come up the first year?
Some thin, slow growth is normal the first year. If nothing came up at all, the crowns may have dried out before planting, been planted too deep in cold or heavy soil, or rotted in soggy ground.
Do I need male and female plants to get a harvest?
No. Asparagus doesn't need a pair to make spears. Most varieties for home gardens are all-male because male plants put all their energy into spears.
How long will an asparagus bed keep producing?
A well-sited, well-prepared bed with yearly mulching, weeding, and feeding can produce for 15 to 25 years, and some home beds go even longer.
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