grow Asparagus in a Greenhouse

How to grow Asparagus in a Greenhouse?

How to grow asparagus in a greenhouse. Plant seeds or crowns in spring, to ensure adequate space and dormancy. 

Water weekly and mulch for moisture. Fertilize late summer with a potassium-phosphorus mix. 

Prune dead ferns in late summer. Watch for weeds, pests like thrips and aphids, and diseases like rust and root rot. Harvest 6-8 inch spears at soil level for fresh eating.


Feel free to grow asparagus in a greenhouse successfully with perseverance and patience. 

You should be fully aware that new asparagus plants are not established rapidly. And, you will have to wait a few years to harvest them.

You can grow Asparagus outdoors such as in a cold frame and greenhouse. However, need to provide them ample space and let them for a certain period.

It can be said that when you start growing asparagus in a greenhouse, you have numerous benefits. You can provide complete protection to common asparagus pests and weeds. Moreover, the complete care of asparagus plants for 5 years, rewards you extra harvests in coming years

How to grow asparagus in a greenhouse?

Asparagus comes under the scope of flowering perennial and you can cultivate it in the shape of a vegetable for thousands of years. However, the best investment is planting asparagus in your greenhouse.

In many climates, you can grow asparagus outdoors, but the only facility for growing it is in only cold frame or greenhouse. To ensure the long life of greenhouse asparagus, you need to know how asparagus grows.

What is the size of this Plant (Asparagus)?

What is the size of this Plant (Asparagus

As far as the size of the asparagus plant is concerned, it grows to four to 5 feet, quite above the soil. Moreover, it also grows deep underground to 10 to 15 feet.

That is why, during planting it in your greenhouse, you need to select a kind of spot that can fit according to its extra growth.

Furthermore, in containers, asparagus can be grown successfully. But make sure that containers can manage their roots.

Asparagus Plants Require the Complete Dormancy

Growing asparagus in the greenhouse can be challenging for you. Because ensures that the asparagus plant goes through a certain dormancy period.

Due to dormancy, asparagus plants gain and store extra energy and nutrients to produce the latest shoots in the spring season.

When you start growing asparagus in USDA zones 3-8, asparagus enters a dormancy period naturally between the winter months and then re-emerges especially in early spring. 

So, then the harvest season is ended, and the asparagus plants start moving to their fern stage. And it is important to promote its healthy root development.

It is also noticeable that if you keep equipped your greenhouse with heaters or grow lights, you can keep growing asparagus plants in the winter.

How can you Plant Asparagus in a Greenhouse?

How can you Plant Asparagus in a Greenhouse

Well, from two major ways, you can plant asparagus in a greenhouse. Crown Cuttings (2 years old planting) and from seed.

It all depends on which plantation method you select. And both methods contain their distinctive benefits.

Beginning with the Crowns of Asparagus

To start asparagus quickly, use crown cuttings. They speed up growth, letting you harvest in just 1 year instead of 3. Growers often sell 2-year-old male crowns because they produce more spears.

Here is how to plant them:

  • Soak the crowns in room-temperature water or compost tea for 30 minutes to rehydrate the roots.
  • Dig a trench 6-10 inches deep.
  • Make a small hill in the trench and place the crown on top.
  • Spread the roots on each side of the hill.
  • Cover the crown with soil.
  • Space crowns 12-18 inches apart, or follow the producer’s recommendation.

Taking Asparagus Seeds and Starting

Starting asparagus from seed takes more time but can result in a stronger crop and allows for unique varieties. Here’s how:

  • Soak seeds in room temperature water for a few hours.
  • Plant seeds in seedling flats.
  • Transfer seedlings when they reach 2-3 inches tall.

Organizing and locating the greenhouse

 When you want to plant asparagus in your greenhouse:

  • Choose a permanent spot with full sun (6-8 hours) or partial shade.
  • Plant them on the edge of a bed or in their own space to avoid shading other plants.
  • Space individual plants 12-18 inches apart and rows 2-3 feet apart.

How to take care of asparagus growing in a greenhouse?

How to take care of asparagus growing in a greenhouse?

The best part is about to start once you’ve planted asparagus in your greenhouse and located the ideal spot! We provide you with the necessary advice in this part to ensure that your recently planted asparagus seedlings or crowns not only survive but flourish.

Watering asparagus in your greenhouse:

  • Aim for moist soil, especially when plants are young.
  • Mature plants can handle some drought.
  • Typically, one inch of water per week is sufficient.
  • Check soil moisture before watering; avoid if the soil is still moist.
  • In summer, apply a few inches of mulch to retain moisture and heat, especially for young plants.

Fertilizing asparagus in your greenhouse:

  • Use high-potassium and phosphorus fertilizers.
  • Apply in late summer or early fall.
  • Avoid over-fertilizing to prevent burn.
  • Follow fertilizer instructions carefully for best results.

 Pruning asparagus in your greenhouse:

  • Wait until the end of summer when ferns turn yellow or brown.
  • Avoid pruning until ferns are completely dead.
  • Cut stalks to the soil level.
  • Minimal pruning is needed, except for tidying up unruly foliage.
  • Avoid excessive pruning of green foliage for healthy growth.

Asparagus Harvesting 

  • Wait until the third year for harvest, or one year after transplanting from crowns.
  • In the first year, let small spears grow into ferns.
  • In the second year, refrain from harvesting to allow plant establishment.
  • During the third year, lightly harvest for 2-3 weeks.
  • Subsequent years, harvest for 6-8 weeks.
  • Harvest spears when they reach 6-8 inches tall.
  • Cut at the soil level to avoid damaging new shoots.
  • Harvest before spears start to open, as they become woody.
  • Enjoy fresh asparagus, cooked, or grilled.
  • Store harvested asparagus in the fridge for up to several weeks, but note flavor loss over time.

FAQs(Frequently Asked Questions)

1). Does asparagus grow nicely indoors?

Be patient as plants establish. After a few years, abundant harvests await. Enjoy a surplus of asparagus for years to come. Requires patience and perseverance, but worth it in the end.

2). How much time does asparagus take to grow?

Starting asparagus from 1-year-old crowns is common, as it matures in 3 years. Despite the wait, plants can be productive for over 10 years. Begin planting in late winter or early spring when the soil is ready.

3). How may asparagus be grown most easily?

Plant in spring, one inch deep. Space seeds 2-3 inches apart in rows one foot apart. Germination takes about three weeks. Keep the nursery bed weed-free to avoid competition for seedlings.


Growing asparagus in a greenhouse is a rewarding endeavor, offering abundant harvests for years to come with proper care. 

Whether from seeds or crowns, providing adequate space, dormancy, and regular maintenance like watering, fertilizing, and pruning ensures healthy growth. Harvesting fresh spears adds the final delight to this enduring investment. Also, read How To Grow Olive Trees In A Greenhouse?