learn how to grow quinoa in a garden

How to grow quinoa in a vegetable garden

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Quinoa is a cool season crop grown for its tiny, protein-packed seeds. It’s also a beautiful vegetable, producing tall plants with silvery-green leaves and brilliant red, pink, and gold seedheads. It’s easy to grow, drought tolerant, and disease resistant with the seed harvest taking place in autumn before the first hard frost. If you want to learn how to grow quinoa in a vegetable garden, keep reading. 

Quinoa seedhead in the fall garden

A single quinoa seedhead can produce around a half cup of seeds.

What is quinoa?

Quinoa is indigenous to the Andes Mountain region in South America and has been cultivated for thousands of years. It grows best in regions where summer temperatures don’t exceed 90 F (32 C), but plant breeders have been working on varieties that grow well in both warmer and coastal climates. The plants of most varieties of quinoa grow four to six feet tall, producing seeds in shades of light tan, red, or black. The plants need a long season to grow and mature with most varieties ready to harvest 90 to 120 days after seeding. 

Quinoa is related to amaranth, also grown for its edible seeds. It’s also a close cousin of the common weed lamb’s quarters, a popular plant among foragers (Learn more about foraging for lamb’s quarters in this excellent article). Like lamb’s quarters, the tender young leaves of quinoa can be eaten. We enjoy them in the same ways we eat spinach; raw in salads as well as cooked in pastas, casseroles, and even dips. It’s important to note that like sorrel and New Zealand spinach, the leaves of quinoa contain high levels of oxalic acid which can increase the risk of kidney stones in sensitive people.

How to grow quinoa from seed

There are two ways to plant quinoa: by direct sowing the seeds in the garden or by starting them indoors. I usually give the plants a heads start indoors under my grow lights. This is because I live in a short season climate and it gives my plants enough time to mature their seed heads.

I first grew quinoa in my garden seven years ago and it’s become an annual crop for me. In fact, I even include it in my award-winning book, Veggie Garden Remix! There are so many reasons to love this plant. First, it’s easy to grow, drought tolerant and bothered by few plant diseases and pests. Quinoa is also beautiful with showy, colorful seedheads and ornamental foliage. Finally, it offers several edible parts: tender young leaves as well as protein-rich seeds. 

How to start quinoa seed indoors

Quinoa is relatively quick to grow and shouldn’t be seeded indoors too early. Sow the small seeds in cell packs and trays or pots four to five weeks before the last expected spring frost. Don’t plant them deeply, just under a thin layer of soil. Place the containers beneath grow lights or in a sunny window and mist the soil often to keep it evenly moist.

The seeds germinate quickly, usually in four to five days. I keep my grow lights on for sixteen hours a day, using an inexpensive timer to turn them on and off. Keep an eye on soil moisture, watering when it’s dry to the touch. Fertilize seedlings with a diluted water soluble organic fertilizer after they have developed their second set of true leaves. Harden off and transplant them into the garden once the risk of frost has passed.

Quinoa seed packet

Wondering how to grow quinoa? You can direct sow in the garden or give the plants a head start indoors under grow lights.

How to grow quinoa: direct seeding

Grow quinoa in a site that offers plenty of sun and well draining soil. Quinoa plants grow great in my raised beds. I prepare the site in mid-spring by amending the soil with compost or aged manure. A slow release organic fertilizer can also be applied at this time if your soil isn’t particularly fertile.

Once the last spring frost has passed and the soil is in the 60 F (15 C) range, direct sow the tiny seeds a scant quarter inch deep. Space them two to three inches apart. Keep the seedbed consistently moist until the seeds germinate in 4 to 7 days. Lay a row cover overtop the bed to help the soil retain moisture. Lift the cover daily to check and see if you need to water. Once the seeds have sprouted, remove the cover. 

seedling in a vegetable garden

Quinoa is a pretty plant with silvery-green leaves. The young leaves can be eaten in the same way as spinach.

How to grow quinoa in a vegetable garden

Quinoa is a low care plant but there are a few things you can do to encourage healthy growth and a heavy crop of seeds:

  • Thin – When the seedlings are a couple of inches tall, thin them 12 to 18 inches apart depending on the variety you’re growing. Shorter varieties can be spaced a foot apart, while tall growing ones should be given at least 18 inches between plants. Eat the thinning in salads. If you wish to grow quinoa solely for the greens, not as a seed crop, space the plants 8 to 10 inches apart.
  • Water – Established plants have vigorous root systems that make them very tolerant of drought conditions. That said, plants that are watered occasionally (or rained on) respond with increased growth and yield.  Mulching the plants with straw helps the soil retain moisture and reduces weed growth. Stop watering at the end of summer when the seed heads are developing.
  • Weed – Young quinoa plants don’t compete well with weeds so pull any that emerge. If you intend to save seeds from your quinoa plants for future crops, remove any lamb’s quarters plants that pop up in your garden. Quinoa can cross with this botanical relative and if that happens, the saved seeds may not grow true to type. 
  • Stake – As noted above, quinoa plants can grow quite tall, mine generally grow four to six feet but I’ve had the occasional plant reach eight feet. Those plants eventually get top-heavy and can topple over in gusty winds. It’s helpful to stake the plants when they’re two to three feet tall. I use six foot tall bamboo stakes or fibreglass stakes, securing the plants to their supports with garden twine as they grow.
quinoa plants in a garden

I often plant quinoa next to magenta spreen, a related plant. They have similar growing needs and habits and offer tender, edible leaves and ornamental seed heads.

How to grow quinoa in containers

No garden? No problem! You can grow quinoa in containers. Ideally, choose large pots or planters. I like fabric planters as they drain well and are available in many sizes. You’ll want to grow at least five or six plants to harvest enough quinoa for a meal so pick a pot that is at least two feet across, or a planter that is two to three feet long. Place the pots in a location that receives plenty of sun. 

Fill the pot with a mixture of potting mix and compost. Two-thirds potting mix to one-third compost is a good ratio. You may also wish to add a slow release organic fertilizer to the growing medium to provide a steady feed all summer long. 

Sow seeds about three inches apart, eventually thinning them to 10 to 12 inches apart. Garden grown quinoa plants are drought tolerant but you’ll need to keep a closer eye on container crops, watering several times a week. Allow the top two inches of soil to dry out in between waterings. Support tall quinoa plants with wooden or bamboo stakes or place containers at the base of a trellis or fence. 

seedhead in a vegetable garden

Quinoa is a beautiful plant growing four to six feet tall with striking seedheads in bold hues of gold, orange, red, or pink.

Common pests of quinoa

Quinoa is generally trouble-free, but I have found a few pests that find the plants attractive. Here are three common pests of quinoa: 

  1. Aphids – Aphids are soft bodied, pear-shaped insects that suck the sap out of plant tissue. They are a familiar garden pest and seldom cause major damage. Aphids are also a favorite food source of ladybugs, lacewings, and other beneficial insects. Because of this, I tend to leave aphid colonies alone to provide food for these good bugs. If they’re still around after a couple of days, and close inspection shows no sign of beneficial insects (look closely, they can be small!) I use a strong jet of water from my hose to knock the aphids off. 
  2. Leaf miners – Quinoa is related to beets and Swiss chard, two crops susceptible to leafminers. It’s therefore not unexpected that quinoa would also be attractive to leafminers. This pest is identified by its damage; brown trails and tunnels on the leaf surface. The damage rarely kills a plant, but it does make it less palatable. If you have problems with leafminers in your garden, float a lightweight row cover or insect barrier fabric over the bed after planting. This prevents the adult females from laying eggs on the leaves. No eggs, no leafminers. 
  3. Slugs – Slugs are a common garden pest that can quickly devor beds of young seedlings or cause damage to mature plants. They can be a challenge to eradicate, but Jessica comes to the rescue with this excellent article on organic slug control methods. Definitely worth a read if your garden is plagued by slugs.
leafminer damage on a leaf

While my quinoa plants are seldom bothered by pests, occasionally I see leafminer damage in early summer. Row covers applied early in the season can prevent leafminer damage.

When to harvest quinoa 

As summer turns to autumn, keep an eye on your quinoa patch. You’ll notice the seedheads start to dry as the plants mature. The leaves also fall from the plant as as harvest nears. Check for maturity by running a hand along a seed stalk. If seeds fall into your hand, it’s time to cut the seedheads. Use sharp pruners to cut the stalks just below the seed head, dropping them into a clean container or bucket. If they’re not fully dried, you can hang them in a dry, well ventilated spot for a week or so. I’d suggest placing a clean sheet beneath the drying heads to catch any falling seeds. 

If frost threatens before the plants are ready to harvest, cover them with a lightweight row cover. Remove it the next morning so the plants can continue to dry in the sun. If rain is in the forecast, harvest as soon as the plants are mature. Note that quinoa self seeds easily so try not to spill too many seeds in your garden. If you find colonies of quinoa the following spring, just turn them over as a green manure crop or dig them up and transplant them to a new spot. 

How to clean quinoa seeds

Unlike grains, quinoa seeds don’t have seed coats to remove and you don’t need any special equipment to clean them. I do clean away chaff (small bits of leaves and debris). The easiest want to winnow them is by tossing them gently in the air in front of a fan to blow away any bits. You can also use a screen to clean the seeds. Once your seeds are clean spread them on a screen or tray to dry for a couple more days. Store the dried quinoa seeds in a jar or container.

Before eating your homegrown quinoa you need to clean it of saponin, a bitter tasting compound that coats the seeds. I put the seeds in a blender with some cold water and run it on a low speed for 10-15 seconds. Rinse and repeat. I usually do this four or five times, or until the water is no longer foamy. Cook equal parts quinoa and water for 15 to 20 minutes or until the seeds are tender.

when to harvest quinoa seedheads

Harvest the seedheads of quinoa when they are dry, seeds come loose in your hands, and the leaves have fallen from the plant.

Quinoa varieties

Many seed companies now offer quinoa seeds in their catalogs. While there are many varieties available, Cherry Vanilla and Brightest Brillant are the two most widely grown in home gardens. They’re reliable, productive, and adaptable to various growing conditions.

Cherry Vanilla – This variety is incredibly ornamental with plants that grow three to five feet tall. It’s a good choice for containers if you wish to plant in pots. The eye-catching seedheads range from pale pink to deep fuchsia, making this crop pretty enough to be tucked into flower beds and borders as well as the vegetable garden.

Brightest Brilliant – Expect to be wowed by the dazzling shades of Brightest Brilliant quinoa. The four to six foot tall plants are topped with seedheads of red, orange, pink, cream, and even gold. Enjoy the young leaves raw or cooked but don’t pluck too many if you want the plants to gather enough energy to yield a large crop of seeds.

To learn more about growing unusual vegetables, be sure to check out these articles:

Now that you know how to grow quinoa, are you planning on growing it in your garden? 

How to grow quinoa in a vegetable garden

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