How to Grow Quinoa in the UK: The Complete Guide

Quinoa is a popular grain, seed or pseudocereal. It is not only nutritious, it is also relatively easy to grow in many climates, including our own here in the UK, and can be a great addition to a home grown diet. This article will show you how to grow quinoa in the UK in plant form.

What is Quinoa?

A member of the amaranth family, quinoa is known by the latin name Chenopodium quinoa. It is a herbaceous annual plant that is primarily grown for its edible seeds.

Human consumption of the plant is believed to have begun around 3-4 thousand years ago in the Lake Titicaca basin of Peru and Bolivia, in its native range.

Can Quinoa Be Grown in the UK?

As you learn how to grow quinoa in the UK, you should be aware of the basics, including its hardiness levels, and where else in the world it can be grown.

Chenopodium quinoa can traditionally be grown outdoors in the garden in USDA zones 10-12. However, there are now cultivars that are successfully grown even in cooler temperate climates Quinoa is now grown here in the UK, as well as in much of the US, and as far north as southern Canada.

It is a warm-season crop that requires full sun, however. Best germination occurs when soil temperatures range from 65 to 75°F. For those with a cooler, more northern location, this means that quinoa grows best under cover in a greenhouse or polytunnel than it will do outdoors.

How to grow quinoa plants as a summer crop can be an interesting option to consider if you would like to save money and become more self-sufficient however, even in northern parts of the UK.

If you fancy growing fruit in your garden or domestic polytunnel, make sure to use our customised fruit cages.

Why Grow Quinoa in Your Garden?

Quinoa is one of the grains that could be a good option to consider for small-scale home growers. While other crops like wheat, oats and barley require a lot of space to provide a worthwhile yield, even a small stand of quinoa in a home garden could yield enough seed to be worthwhile.

Did you know that as you learn how to grow quinoa, it is relatively easy to grow at home?! And the good news is that it will grow in a wide range of climatic conditions. It is related to chard and beetroot and it will produce a quantity per plant, so require far less space to grow than common grains like wheat.

Quinoa can be cooked like rice and is high in protein. It is one of the few sources of complete protein that is suitable for vegans, and so can be a key part of an eco-friendly vegan or vegetarian diet. Giving up meat (or at least reducing your consumption) is one of the very best ways to reduce your carbon footprint.

As you may or may not recall from high school science lessons, protein is made up of amino acids, nine of which must be obtained from the food we eat. A ‘complete’ protein source is one which provides all these essential amino acids.

All meat, seafood, eggs and dairy are compete protein sources – but you can still get enough of all the essential amino acids through a vegetarian or vegan diet.

Even if you are unable to rear your own livestock or keep any animals, you can still make sure your home-produced diet is rich in protein – doing a service to our planet by eschewing meat and dairy while you are at it.

Quinoa can provide around 1696 calories per lb, which means that it can be a cost-effective use of space when trying to make the most of the land and generate a yield for self-sufficiency.

Another good thing about quinoa is that it can be harvested without any specialist equipment.

Where to Grow Quinoa

Quinoa can be grown outside in your garden, or in a polytunnel or other undercover growing area. Quinoa will do best in areas which have relatively short days with cool night temperatures and daytime temperatures below 35 C.. The plants tolerate night time temperatures as low as -2 C.

The plants will do best in sandy or loamy, well-drained soils with low nutrient content, moderate salinity and a pH of between 6 and 8.5. They will benefit from the addition of available nitrogen to the system and may do well, therefore, when interplanted with nitrogen fixing plants such as legumes.

Sowing Quinoa

As you learn how to grow quinoa, it is best to sow quinoa in around April either in seed trays for later transplantation, or where it is to grow. Wait until after there is no longer a danger of frost in your area. Cover the seeds you sow with a thin layer of compost – no more than ¼ inch deep. Space your quinoa seedlings around 1-2ft apart and expect the plants to grow almost 6ft tall (when they will require staking) in optimum conditions.

One thing to note as you learn how to grow quinoa seedlings is that they strongly resemble the common weed known as Lamb’s Quarters during the initial stages of growth. So if you have direct sown, be careful not to weed them out by mistake.

Thin seedlings out (or transplant) as soon as they are large enough to handle. You will find that the rate of growth will tend to be slow initially. But then the plants will have a sudden growth spurt and will quickly grow to their eventual height over the summer months. Flowers will form in around June or July, and seed heads will then begin to form.

Caring for Quinoa

Quinoa will require some watering in extremely dry conditions, or if grown under cover. However, it is important not to over water.

Other than watering, your quinoa will require little care. Quinoa is generally unbothered by pests and the seeds’ bitter coating prevents then from being eaten by rodents or birds. You may find that the leaves get small holes from flea beetles. However, this will not usually affect the growth of the plants.

How to Grow Quinoa: Harvesting Techniques

The quinoa is ready to harvest as soon as the seed starts to form and the flower heads begin to change colour. (In around September or October.) Rub the flower heads gently between your palms and when the quinoa is ready to harvest, you will notice that some seed can be rubbed out easily.

Drying the Seeds (Step One)

Once your quinoa plants reach this stage, cut the heads and put them somewhere to dry out for a few days. The best way to do this is to hang them up with something below them to catch the seeds as they fall out. Good airflow and low temperatures are essential to prevent the plants from beginning to get mouldy. You can also help with this process by removing any larger leaves and bits of stem.

Separating the Seeds

After drying out the seed heads for a few days, any seeds that have not already fallen out can fairly easily by rubbed out by hand. Simply roll the heads gently between your palms to knock out the seeds. (You will now have a pile of seeds, but there are likely to also be several bits of plant in there too.)

If you have a riddle, you can use this to separate out the seeds. However, if you do not have one, you can simply pick out the larger pieces by hand. Now you should have a pile of seeds in their flower bracts that are somewhat dry, but which need to be dried out a little more.

Drying the Seeds (Step Two)

Lay out the seeds in their flower bracts in a thin layer on a baking tray or sheet and put them somewhere to dry. Give them a quick stir each day as you pass to make sure it all dries well. When fully dry, the seed can be easily rubbed out of the flower bracts (between two palms).Wearing some rubber gloves could make this process easier.

Winnowing

Once you have a pile of seeds, separated from their flower bracts and other small pieces of debris, you should winnow them. Winnowing basically involves pouring the seeds gently from one container into another in a breeze, so that small, light pieces and lighter, unviable seeds blow away.

Using & Storing Quinoa

Before using your quinoa, you will need to soak your seed overnight, and rinse it a few times in cold water. This will remove the coating that naturally protects the seed from insects, rodents and birds. You can also store the seeds in an airtight, dry container for later use. When stored correctly, quinoa seeds can be kept for around a year.

Quinoa can be used in any recipes where you might ordinarily consider using rice or couscous. It can be used as a side dish, or as part of the main event. It can be used to stuff a range of vegetables, or to make stews, casseroles or bakes. You should have no difficulty in finding uses for the quinoa that you grow.

Production Cycle of Quinoa

To know how to grow quinoa plants efficiently in the UK, here are the accurate steps to take throughout the year.

April – Planting

• Plant tiny seeds at a sensible depth to ensure they emerge successfully.
• Seeds germinate fast but are slow to establish until the weather gets warmer.
• The crop needs to grow quickly so that it can stay ahead of weed growth.

May – Weed control

• Evoke sensible weeding methods to reduce number of weeds that will grow.
• Avoid using artificial herbicides.

June – Flowering

• Will begin to flower in the summer when seeds begin to develop.
• Seeds will be initially full of water as summer progresses they will start to swell and become denser.

September – Harvest

• Crop will start to mature in the summer sun; combine harvester can be used to collect seeds from head of the plant.
• Rapidly dry them to preserve quality. 
• Store collected seeds in a dry environment such as a shed until ready for cleaning.

October – Cleaning

• After harvesting the crops prepare them for consuming.
• Weed seeds and chaff to ensure purity, and will help remove small and discoloured quinoa grains to ensure a good quality product.

For more tips about polytunnel gardening, learn about growing grains in a polytunnel now.

FAQs

Sources:

Plants for the Future (n.d.) Chenopodium Quinoa – Willd. [online] Available at: https://pfaf.org/user/plant.aspx?LatinName=Chenopodium+quinoa [accessed 05/09/23]