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Growing Amaranth To Harvest Glorious Grain

You may have heard of the ancient grain amaranth, which is an amazing food similar to quinoa and packed with protein. This crop has been cultivated for thousands of years in America and is valued as a superfood throughout the world.  Growing amaranth is easy!

There are many varieties of amaranth plants that can grow to towering heights, up to 10 feet tall!  Its stalk is a popular fun trellis for vine plants such as beans and peas to climb up.  The grain provides food for birds and the flowers are adored by bees. Amaranth is also a warm-season leaf vegetable, with edible leaves that can be enjoyed like salad greens.

Let’s find out more about the varieties of amaranth and harvesting this amazing food!

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Quick Care Guide

Growing amaranth
When growing amaranth, you’ll get beautiful plumes of flowers. Source: Melinda Young Stuart
Common Name(s)Red amaranth, Prince’s Feather, Love Lies Bleeding, Copperhead, Hopi Red Dye, Hot Biscuits, Red-Rooted Pigweed
Scientific NameAmaranthus hypochondriacus, Amaranthus cruentus, and Amaranthus caudatus 
Days to Harvest90-150 days
LightFull sun
Water:1-2 times a week 
SoilRich, well-drained soil
FertilizerOnly once when sowing the amaranth seeds
PestsTarnished plant bug, amaranth weevils, flea beetles
DiseasesDamping off, root rot

All About Amaranth

There are many varieties of amaranth plants, yet the ones commonly grown for grain are the Prince’s Feather (Amaranthus hypochondriacus) and Red Amaranth (Amaranthus cruentus).  

Other common names include red-rooted pigweed, purple amaranth, and velvet flower. 

Amaranthus originates from Central America and North America, but there are many amaranth varieties found around the world such as in Africa and Asia.  Amaranth plants have a wide range of heights from 2-8 feet tall!  The stalks that form from the main taproot are sturdy and tough.  The leaves are broad, with long, narrow, bushy flowers that range in color from burgundy to golden yellow or green.  Tiny seeds will develop on the flower head, which ranges 4-12 inches long.    

Once planted, amaranth seeds will germinate in 3-10 days and seedlings will appear to grow slowly.  When the plant reaches 1 foot tall, then it will start to grow rapidly in height and produce beautiful flowers. The grains will be ready to harvest in the fall once the flowers are brown and dry. 

The young tender leaves of Amaranthus cruentus are edible and can be used as a replacement for leaf greens, or mature leaves can be sauteed. Amaranth is a highly nutritious food with gluten-free seeds that are packed with protein.  The seeds are often referred to as grains and can be ground into flour, popped, pressed into an oil, or cooked similar to rice. If you are into fresh sprouts, the tiny seeds can be sprouted and enjoyed as microgreens!  Some have used the plant as a dye, in a herbal shampoo, or even as a nourishing crop for their livestock.  

There are so many fun varieties of amaranthus to grow in your garden!  There are the long flowing flowers of Coral Fountain (Amaranthus caudatus), the multicolored Joseph’s Coat (Amaranthus tricolor), or the large flowers of the Elephant Head (Amaranthus gangeticus). It is easy to get lost when you search all the amazing heirloom varieties.  I have a hard time choosing which amaranth seed I want to plant first!

Planting Amaranth

Since amaranth is a sun and warm loving plant. The best time of year to grow amaranth plants outdoors is in mid-spring to early summer.  If you want to start earlier, plant the seed indoors 4-6 weeks before the last frost has passed in your region.

Amaranth grows easily in many soil types but thrives in a well-drained, fertile, loamy soil.    Plant directly into the ground in rows, raised beds, or large containers (10-18 inches in diameter) that receive lots of sunlight.  For plants started inside, you can transplant once your last frost date has passed. 

Many choose to grow amaranth near the border or towards the back of the garden.  It is a great companion plant and can be incorporated into the 3 sisters vegetable guild of corn, beans, and squash…try using amaranth in place of the corn and watch the beans climb up the amaranth stalks!  Alternatively, try incorporating amaranth with other vegetable crops or produce in your garden. 

Care

Amaranth flowers
In time, these stunning flower stalks will form seeds. Source: adstream

Amaranth needs little maintenance and is relatively free of pests and diseases.  The more space and air circulation they get in the garden, the larger the plants!  Let’s explore how to provide adequate care for growing amaranth and how to harvest the leaves and grain. 

Sun and Temperature

Amaranth needs full sunlight, with a minimum of 6-8 hours. The USDA growing zone ranges from 3-10.  The ideal temperature for germination is 65-85 degrees Fahrenheit.  When young, this crop is not tolerant of cold temperatures and is susceptible to spring frosts, whereas mature plants can tolerate the first frost of the fall.  This plant loves hot temperatures and can tolerate heat up to 95-100 degrees Fahrenheit. 

Water and Humidity

Amaranth is a drought-tolerant plant, yay! The main time to focus on watering your plants is when the seed is germinating and when they are young seedlings.  You will want to keep the soil moist, and once plants are 2-4 inches tall, you can water 1-2 times a week. Amaranth is very water efficient and will survive without being watered for a few weeks if you decide to take a vacation! 

The best time to water amaranth is in the early morning or late afternoon and focus water towards the base of the plant on the roots, using a directed sprayer, a soaker hose, or drip irrigation. Avoid watering the flowers and grain.  Humidity requirements are not necessary for amaranth.  

Soil

Amaranth loves rich well-drained soil. It does tolerate poor conditions, but may not be as vigorous in dense clay soils.  Consider adding compost and peat moss to increase the organic material and drainage.  The optimum pH level range is 6.0-7.5. 

Fertilizing

Since amaranth plants are low maintenance, fertilization is only necessary if you have poor growing conditions.  Add fertilizer like fish emulsion or worm castings when you first plant the amaranth seeds and you are good to go!  Alternately, work some composted manure into the bed in advance of planting and skip fertilizing entirely. Keep in mind that nitrogen-heavy fertilizers such as manure are not recommended. 

Pruning/Training

Pruning is not necessary for this annual plant, yet to promote more flowers, trim back the top half of the young plant when it’s still young.  This will promote more stalks to grow which equals more flower heads! Tall varieties may need additional support, as they can bend or break in high winds or storms. Place a trellis, netting, or individual stakes at the time of planting and gently tie the stalk of the amaranth to the support as it grows. 

Propagation

Amaranthus is propagated by seed.  The seeds are incredibly tiny!  You can choose to broadcast them and cover them lightly with soil.  Alternately, sow 1-2 seeds per shallow hole, ¼ inch depth about 4 inches apart.  Keep soil moist during germination. 

Thin young plants to 18 inches apart when their first true leaf has sprouted.  The amaranth seeds fall easily from the flowers and plants themselves, so you can expect this annual to pop up every year! 

Harvesting and Storing

Amaranth greens
Some amaranth has edible greens that can be cooked like a vegetable. Source: avlxyz

The beautiful blooms can be enjoyed as cut flowers, but we also want to harvest amaranth for food and enjoy the tasty greens and the nutritious seeds. Let’s explore some methods in harvesting the grains and leaves.

Harvesting

First, let’s harvest amaranth leaves.  Young leaves are ready for harvesting 25-40 days after planting.  You can harvest the entire top half of the amaranth plant for the young leaves, and the stem will regrow with multiple stalks.  Alternately, pluck off the young leaves on the top half of the amaranth.  Mature leaves will be tougher and not as desirable. 

To harvest for amaranth seed or grain, wait until the flowers are brown and dry in the fall.  You can even wait until after the first hard frost to harvest the seeds.  Cut the entire flower stalk and sit out in a dry place for a few weeks or place in a paper bag. 

Storing

The edible leaves are best eaten fresh and are considered highly perishable.  Amaranth leaves will last a few days in the fridge if you wrap them in damp paper towels and store them in a plastic storage bag.  You can also parboil the leaves, drain them, and put them in the freezer for longer storage. 

To retrieve the seeds from the flowers, use your hands to rub out the seeds, or shake seeds loose in a paper bag or clean pillowcase.  To remove finer chaff, use your breath to gently blow it off or slowly exchange seeds in a slow waterfall motion between 2 bowls and let the finer chaff fly out in the breeze.  Store seeds in an airtight container and place them in the fridge, and they will last 6-8 months. 

Troubleshooting

Closeup of amaranth
An extreme close-up of an amaranth flower. Source: Rich Gibson

Amaranthus is a relatively pest-free plant that grows vigorously in the garden.  Yet you might find that your plant is not growing as tall and strong as you’d like, or something is nibbling the leaves.  We will discuss how to troubleshoot some of these potential problems. 

Growing Problems

If your crops are in the shade or densely planted, you will notice that your amaranth will be smaller.  You will want to adjust the available sunlight if other plants are shading your amaranth or thin out the amaranth to 18 inches apart so that there is proper circulation of air. 

The temperature may be a factor in growing issues.  Amaranth loves hot sunny weather, if you are located in a cooler region, you may want to locate your plant in the hottest part of your garden and use rock mulch.

Pests

Visible damage to leaves may be caused by amaranthus stem weevils.  Their larvae chew on the roots. Growth will be stunted and stalks may start to twist.  Try to prune out infected leaves and remove any of the larvae that you find but most likely you will need to remove the plant completely from the site.  Neem oil has had some effect in reducing numbers.

Tarnished plant bugs will attack the seeds and flowers by sucking out the liquid.  This diminishes seed production.  You can apply the organic pesticide pyrethrin to eradicate the infestation. When plants are young, floating row covers can keep them at bay.

Flea beetles love seedlings, you can try a preventative measure against these pests by using a floating row cover.  If the infestation is mild, you can apply diatomaceous earth or kaolin clay.  For severe infestations, use pyrethrin.

Diseases

There are not really that many diseases threatening the resilient amaranth.  The main concern may be damping off, which will occur with produce crops during the younger plant stages.  Plants may die off suddenly from too much nitrogen or overwatering.  To prevent this, try to limit the use of fertilizer and allow the soil to dry between waterings.  You can also thin out the seedlings to encourage more airflow and make sure your planting containers are sanitized.

Root rot can also impact the growth of your amaranth. This is typically caused by overly wet conditions, and can easily be remedied in the future by ensuring your soil is well-draining. Plants that are currently suffering from root rot may benefit from less frequent watering but often won’t stay green and healthy. If the plant dies, remove it and do not compost the roots to avoid spreading the fungal pathogens that cause root rot.

Frequently Asked Questions

Ornamental amaranth
Ornamental amaranths are quite popular in gardening. Source: the queen of subtle

Q: Why is amaranth banned in the US?

A: Great question! Growing amaranth is not banned. Instead, the amaranth dye added to commercial food products is banned.  The plants are very commonly grown in gardens around the US.

Q: How long does it take to grow amaranth?

A:  It takes 90-150 days to grow amaranth, depending on the variety!

Q: Is amaranth easy to grow?

A: So easy!  It is a fun and effortless plant for your garden with stunning flowers and provides unique food for the family.


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