Learning how to grow asparagus is simple. Asparagus is a dependable favorite in the home garden. It takes two or three years for the plants to be ready to harvest, but they keep making tasty spears for another ten to fifteen years. Asparagus stalks increase in circumference and number over time — it definitely gets better with age.
I love picking a fresh spear and handing it to garden visitors during asparagus season. Their eyes light up when they taste freshly-picked asparagus for the first time. This is one vegetable that tastes best straight from the garden.
Asparagus is a delicious and nutritious vegetable that also happens to be easy to grow However, timing is critical when it comes to planting asparagus crowns or seeds. This perennial favors cool weather and can be particular about transplanting So is it ever too late to plant asparagus? Let’s explore the ideal times and techniques.
When is the Best Time to Plant Asparagus?
Asparagus crowns or one-year old seedlings are typically planted in early spring as soon as the ground can be worked This gives the plants time to establish roots before hot summer weather arrives
The optimal window is between mid-March and mid-May in most regions Wait until after the threat of hard frost has passed Asparagus grows best when daytime temperatures are around 70°F.
Planting in early fall is another option in mild climates. Fall-planted asparagus should be mulched heavily for winter protection.
Is Late Spring Too Late to Plant Asparagus?
Late May or early June is pushing the limits of appropriate planting times in many areas. At this point, soil and air temperatures are warming significantly. Asparagus prefers cool roots and will suffer transplant shock if planted when it’s hot.
If you must plant asparagus crowns or roots in late spring, focus on providing cool soil conditions:
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Heavily mulch the beds with straw or leaves to moderate soil temperature.
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Water the plants frequently to keep roots moist and cool.
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Provide afternoon shade if possible.
The plants may be stressed and slow to establish for the first year. Be patient and care for them properly and they should perk up and thrive.
Can You Plant Asparagus in Summer?
Summer is a risky time to plant asparagus. The key reasons are:
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High temperatures will shock the transplants.
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Asparagus crowns and roots need 2-3 months of cool weather to establish before going dormant.
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Hot, dry weather makes it difficult to keep the plants adequately watered.
If you live in a very mild climate and are able to provide deep, consistent watering, you may have success planting in early summer. Otherwise, it’s best to wait until early fall or the following spring.
Planting Asparagus in Fall for Spring Growth
In areas with mild winters, planting asparagus in fall for harvest the following spring is an option. Timing depends on your local climate:
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Northern areas: Plant 8-10 weeks before first frost so plants have time to establish.
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Southern areas: Wait until the weather has cooled to plant. Avoid late summer heat.
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Prepare beds and amend soil a few weeks prior to planting.
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Mulch beds well to protect from hard freezes.
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Start harvesting spears lightly in spring 2 years after planting crowns.
Fall planting gives roots the cool conditions they prefer. Just be sure to provide winter cold protection where needed.
Growing Asparagus from Seed
If spring or fall planting isn’t possible, or you want inexpensive plants, growing asparagus from seed is an alternative.
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Start seeds indoors 10-12 weeks before your last spring frost date.
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Transplant outdoors after hardening off when soil is warm, around mid-May to early June.
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Allow these seedlings to grow and overwinter in a sheltered nursery bed.
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The following spring, transplant one-year-old crowns to permanent beds.
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You’ll wait an extra year for harvest compared to purchasing crowns.
Ideal Conditions for Growing Asparagus
Whenever you plant, be sure to give asparagus ideal growing conditions:
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Full sun
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Well-draining loamy soil, high in organic matter
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Soil pH between 6.5-7.0
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Consistent moisture, especially early on
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Space crowns 12-18 inches apart in rows 3 feet apart
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Avoid wetting foliage, which can cause disease
Proper site preparation, timing, care and patience will reward you with an abundant asparagus harvest for 20+ years!
Common Questions about Planting Asparagus
Is it too late to plant asparagus in June?
In most climates, yes – late spring to early summer is too late to plant asparagus crowns or roots. Temperatures are too high, causing transplant shock. Wait for an early fall planting window instead.
When should I plant asparagus crowns?
Ideally, plant asparagus crowns or one-year old roots in early spring as soon as you can dig the beds. Mid-March to mid-May is the optimum window in most regions. Plant in fall at least 8 weeks before a hard frost for an early spring harvest.
Can I plant asparagus in July?
It is best to avoid planting asparagus in mid-summer. The heat will stress the transplants, and they need cooler temperatures to establish healthy roots before going dormant in winter. Start seeds indoors in mid-summer for spring planting instead.
Is September too late for asparagus?
In southern regions with mild winters, early September may still be suitable for fall asparagus planting. In colder climates, plant 8-10 weeks prior to the average first fall frost so roots have time to get established before winter dormancy.
How late in the year can asparagus be planted?
In warm regions, asparagus can be planted through early fall until about 8-10 weeks before your average first frost date. In cooler areas, it’s best planted in spring or early fall no less than 2 months before freezing weather arrives.
Decide on the best location to plant asparagus
Because asparagus plants produce for several years, they require a dedicated bed for that period of time. Choose a location that gets at least 6-8 hours of sun daily. Avoid windy areas and areas where water puddles.
Use raised beds if possible because asparagus roots become soggy and may rot in clay soil. Asparagus needs rich, well-amended soil that is high in phosphate.