How to Grow Amaranth: 29 top tips
Updated: Jul 23, 2022
Not only does Amaranth compete with weeds and help retain ground moisture, it also helps attract predatory ground beetles and is an absolute powerhouse helper for corn. Yup, this ancient grain is high in Vitamin C and versatility! Technically, Amaranth plants are considered an annual plant; however, some view them as a very short lived perennial as it is possible to get more than one harvest from them.
Either way, these often overlooked as a crop to grow, it’s quite helpful and adds gorgeous color to your vegetable garden. Hopefully by the end of this article, you’ll take a chance and give growing Amaranth plants a try. I think you’ll be pleasantly surprised and eager to see it there again in the future.
In case you’re short on time, I’ll get to deal breaker facts first, and then dig in a little deeper on fertilizing and mulching this warm climate loving crop, plus other important tips for growing amaranth after these top
Amaranth seeds grows best when directly sown when soil temperatures are between 65°F - 77°F (25°C), and air temperature is between 68°F - 86°F. It’s important that you wait until after the soil has warmed up enough. In some regions this may not be until late spring and that’s ok.
As it grows, amaranth plants need warm weather throughout its entire growing season (40-50 days for seed harvesting), though it doesn’t do well in extended periods with temperatures above 95°F (35° C). Although amaranth requires full sun - the Joseph’s Coat variety does well with some afternoon shade.
Amaranth plants prefers light, well-drained, fertile soil. Since seedlings need light, non-compacted soil with a low clay content for sprouting. This includes when planting. Try to only lightly cover the seeds with a sprinkling of soil
When it comes to soil, amaranth does best in ones that are fairly neutral, with a pH between 6.0 – 7.0. It can also tolerate fairly extreme conditions once established, and it can grow in slightly acidic or slightly alkaline soils.
Plant the seeds a quarter inch deep in full sun, spaced out the rows about 1-2 feet apart to reduce competition and promote good airflow (which helps to prevent fungal diseases from festering).
If you’re transplanting, the best time to started them indoors about 4-6 weeks before the last frost is expected. If starting them outdoors, you should be good to go if you start planting them a week or two after the last frost date in your region.
Now, all that’s left is time. Grain Amaranth is particularly slow growing at the start, so just need a little patience. They’ll get there.
Before planting your seeds or transplants, thoroughly weed your garden bed(s) to remove any competition and to reduce the risk of pests.
Prepare a garden bed that gets full sun and has loose, uniform soil. Turn your soil under at a depth of about 8 inches and then smooth it overusing a rake. Make sure you remove all rocks and crumble up any large soil chunks.
Amaranth will grow well in rich soil - so you can apply some organic matter like compost. Work it into your topsoil, and then make sure the surface is smooth and level.
Plant your amaranth seeds a quarter inch deep, in rows about 2 feet (60cm) apart, with 6-18 inches between your seeds. It’s a good idea to seed closer together to ensure a successful crop, and then you can thin later.
Since Amaranth seeds are quite small, the best way to plant them is called the “toothpick method” when planting seeds. Start by putting the amaranth seeds in a bowl, wet a toothpick, and then dip it in the seeds to pick up 1-2 seeds slowly transplanting them from the toothpick to their destination.
In general, it should then take about 10-14 days for your seedlings to germinate. As they start to pop above the soil, then your young plants to about 10-18 inches apart from one another.
You’ll want to water after sowing or transplanting your young plants. If you’re sowing your seeds early in the season, your soil should still have a lot of moisture - so be sure not to drown your seeds! Then, you won’t want to water them again until your seeds have germinated and have 2-3 leaves.
Whenever you do water your amaranth, be sure to do so in the morning so that amaranth leaves have the afternoon to dry off (which helps prevent fungal growth!). Make sure you also keep your soil evenly moist, but not wet.
Keep in mind thought that overwatering leads to wet soil, which promotes root rot diseases and slows the growth of your plants. Root rot is a disease that ends up stunting the growth of your plants. A few things to keep and eye for is grey, black or red lesions that often will start to end up showing themselves along the lower end of your stems.
If these signs start to pop up, improve your soil’s drainage, or even better, proactively avoid working in compacted and wet soil to try and avoid it. Oh! And watch your nitrogen levels, that will also help here. 😊
Thin larger grain varieties of Amaranth so that there’s approximately 18 inches between your plants in a row. Joseph’s Coat, however, it’s a smaller amaranth species / variety and will grow just fine with only 6 inches between each plant.
When seeds have germinated and the seedlings are still small, mulch can be added to your bed to keep weeds from popping up. This is an important step to do, especially while your plants are young. Just make sure to keep mulch away from your plant’s stems and leaves to avoid fungal and/or bacterial growth.
As Amaranth can be quite heavy, they often benefit from some support. Simple tomato cages or a trellis works nicely. Simple is good, the key is to help support them from falling over.
These big beautiful plants can grow to be quite massive, extending over 6 feet tall if left to go wild. One way to keep the flower heads more manageable is to do what’s called “pinching off” the amaranth flowers. To pinch, cut back the center flower heads once your amaranth is about 2 feet tall.
Did you touch the seed head and find some seeds falling off? Sound like they may be ready to be harvested for Amaranth grain. People often seem a little nervous about this part, but it’s less complicated than it seems. Simply take the seed heads in your hands and rub them over a bucket to catch the seed. The latter method will require multiple harvests in this manner to remove any remaining seeds as they dry. It also reduces the amount of debris and chaff that needs to be removed.
Once you’ve harvested the amaranths, make sure their completely dried before you put them into storage to better avoid developing mold. Simple spread them out on a dry and them sit in the warm sun or inside near an indoor heating source. Stir them from time to time so that all sides have a chance to soak in that sun. If then stored in an air tight contain somewhere dark and cool, they should last for up to 6 months.
And although Amaranth plants aren’t heavy feeders, they still need care. Below is how to grow amaranth with the plant food and protection that it’ll thank you for.
Fertilizing Amaranth: Here’s the good news, fertilizer isn’t really needed when growing amaranth. Think of it as optional; however, if you know you have poor soil, then it’s in your amaranth’s best interest to add some fertilizer. As easy going as Amaranth plants are, they still don’t tend to do well in poor soils. Important point on this topic: keep in mind though when feeding them is to avoid nitrogen fertilizers, as these can cause the toxic buildup of nitrates in your plant’s leaves.
Mulching Amaranth: Mulching can be used to keep weeds at bay, which is particularly important for your young seedlings. Just be careful not to cover the seeds, as they don’t like to be buried. Mulching is also a good way to regulate both soil temperature and moisture!
Mulching is only needed in the early stages of growth though, because most amaranth varieties grow tall and wide enough that their leaves keep the soil well-shaded.
Add natural materials like shredded leaves, coconut husks, pine park, or grass clippings to your amaranth plants - all these options will do the trick!
Protecting Amaranth plants against pests: Like any leafy vegetable, Aphids and Weevils love this crop. Insecticidal soaps works well for Aphids, and floating row covers for protection against Weevils. Personally, I avoid using commercial pesticides is that they often come with a warning to "wait to pick", with a broad-spectrum formula that aren't really meant to be ingested by humans – no thanks!
Easy peasy, right? Whether you’re growing it for amaranth grain crop, leafy greens, or as ornamental plants (I especially love red amaranth for this! ), there are varieties in the amaranth family for every garden. Bonus, the leafy greens of your amaranth plant are typically edible, so you can enjoy far more than just the amaranth grain that you collect from your amaranth plants flower heads. [CLICK HERE] to learn more about solutions to Amaranth diseases and pests, as well as a video on everything you need to know to grow your own amaranth crop in your vegetable or home garden.