Top Of The Crops - Asparagus

If you love eating Asparagus, it’s crucial that you learn how to plant it too. Although the plant may not give you the rewards you want for several years, it’s important to keep taking care of it. Once it starts showing its stride, it will provide you with a rich set of crops every spring for the next twenty to thirty years!

Unlike other types of vegetables, the Asparagus is a perennial crop. This means that it can always keep growing in your garden. The spears that we love eating are just the new shoots which mostly emerge during spring. The crucial part of planting Asparagus is learning that they need several years to mature before harvesting. Therefore, it will take you some seasons to finally enjoy a tasty meal of Asparagus.

You should waste no time in planting this fantastic crop. It can grow in several parts of the country but does tremendously well in regions with cold temperatures. Besides, it’s one of the most sought-after winter crops that you’ll come across. You can also plant it in a polytunnel for proper growth and protection.

This simple planting guide will take you through all these processes to help you out when you finally decide to grow some Asparagus. With that said, here’s all that you’ll ever need to know:

Growing Asparagus in Polytunnels

A polytunnel is not only used for planting of annual crops. You’ll find that it also provides more protection for different types of perennial crops such as Asparagus and Artichokes. These are two perennial crops that grow well in such a structure. For instance, Asparagus needs adequate shelter, favourable sunlight and a place where it’s safe from high winds.

Another reason why a polytunnel is perfect for perennial plants is that plants grow in one position. After planting your Asparagus; you’ll leave it growing in the structure for quite some time. As it keeps on maturing, you can remove the bulbs and enjoy its sweet flavour. In this case, you won’t have to move the plants in your polytunnel as they will just wear out with time.

Free Drainage Soil - It’s always good to plant your Asparagus in fertile and loose draining soil. A polytunnel allows you to choose the type of soil you need. However, in a garden, you’ll probably have to use a lot of organic manure to get the soil fully fertile.

Protection - Frost and wind are enemies of Asparagus. They even cause the water in the crops to crystallise further damaging its cells. However, with a polytunnel, the plant is protected from ice and frost.

Warm Soil - Remember to give your Asparagus good, warm soil for stronger growth and a much-improved growing season. Even so, these plants don’t like too much heat, so it’s better to plant them in colder parts of the structure. Suitable examples include near ventilation windows or doors.

Good Pest Control - Several pests like to feed on Asparagus eventually spoiling your expected harvest. Some of the notorious insects that might invade your polytunnel include Aphids, Ladybirds, Spiders, and Ants. But you shouldn’t panic when faced with a pest invasion. You’ll only need to maintain a fresh breeze running through the structure. It will blow away these tiny insects and also assists in preventing fungal spores.

Seed Sowing

While you can quickly grow Asparagus using seeds, many farmers prefer using crowds of 1 to 3 years old. However, before planting, you should prepare a suitable growing area for these crops.

Here is how to go about it:

  • Dig a trench that’s around 30 to 20cm deep. Enrich the bottom of the trench by using well-rotted organic matter and then create a ridge of 10cm at the bottom of your channel.
  • Place your crowds at the top by carefully spreading the roots out on either side.
  • Slowly re-fill your trench with the removed soil, but ensure that the tips of the buds are still visible.
  • Lastly, water and adequately mulch your crops with weed-free manure.

It’s essential that you remove all weeds growing around your crops as they don’t take competition too kindly. So instead of using a rake, it's better to use your hands as it helps you not to damage the good crops!


To plant Asparagus the following guide will help you:

  • You should prepare your soil by placing close to 3 inches of organic matter in all rows. You can use leaf mould, or compost manure or anything else that can improve soil fertility.
  • Also, have your bed tested and add some lime if you find that the pH is below 6.5.
  • Before planting your crops in spring, you should first mulch during winter. You can even choose to plant an impressive seasonal cover crop which you can harvest before planting your Asparagus.
  • When you start planting, dig a shallow hole of 6 to 8 inches deep and space your seeds 12 to 18 inches apart.
  • Cover them with fertile soil and feed them using bonnie vegetable and herb plant food twice in a week.
  • Be patient even as they grow through the coming years.

It’s advisable to wait for at least 2 to 3 seasons before you start harvesting. Although you’ll feel compelled to uproot them as soon as spears begin to emerge, it’s wise to easy on the crops until they finally mature. Don’t worry; you’ll be adequately rewarded in the long term!


You’ll need a lot of discipline while harvesting this fantastic crop as spears start appearing within the first two years. If you collect them earlier than this, you’ll end up destroying the plants or severely stunting their growth. Here are some of the necessary steps to follow when the time finally comes for you to harvest your Asparagus:

  • Harvest them once the spears start appearing in spring. They should be 6 to 10 inches above the soil surface. Remember to do this before the buds open.
  • You can snap or cut off the spears while at their ground level.
  • Continue harvesting your crops for about eight weeks.
  • If you find that there is decreased vigour and production in your vegetables, stop the entire process and allow the plant to keep more energy for the following season.
  • If you notice spears which are above 10 inches, let them keep continue growing for firmer roots and improved strength for harvesting in the next season.

In April, you’ll need to water and provide your crops with proper ventilation. Keep in mind that just like in August; sunlight is stronger in April too! Sometimes, it might not feel as if it’s warm enough. But in the polytunnel structure, plants begin to heat up extremely fast.

If you don’t take care of them, the constant heat and lack of water will cause your crops to wither and die. In the garden, take care of slugs and other breeds of pests which may damage your Asparagus. Once you deal with them in April, they will not cause any problems as the year progresses.

As we’ve previously mentioned, you’ll probably have to harvest your Asparagus within their third year. Here, harvesting should start when the stems are around 5 to 8 inches to avoid weakening or otherwise killing the plant. Once you know how to harvest your Asparagus, you’ll have an easy time doing so in future. With such a simple growing guide, you’ll quickly get high yields for several years (15 to 30yrs) as the vegetable starts improving in abundance.


Planting Time

March to April

Harvesting Time

April to May, after two to three years from the time of planting


After harvesting, you’ll need to allow your spears to grow naturally. They will go up to 6 feet high with light-green and lacy foliage. During this time, keep the garden adequately mulched, watered and free from weeds. Always remember that maintaining rich fertile soils as the crops grow rewards you with a bountiful harvest the next season.

So, these are just the most important tips that you’ll need to consider before planting your Asparagus. They should guide you through the entire process, whether you choose to plant them in a polytunnel or in an open garden. However, you’ll find that it’s better to grow them inside a polytunnel as this protects them from the harsh winds and unpredictable climatic conditions.

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