Plant Profile- Grain Amaranth

When most people talk about staple crops they mean grains. Of the world’s most produced crops grains take the top three places (corn, wheat and rice) with a tuber crop coming in at a respectable fourth place with potato. Grain crops have the advantage of being easier to harvest, transport and store than tuber crops since they don’t contain nearly as much heavy water and can be handled and poured more roughly than tubers without causing significant damage. As a result grains are transported all across the planet while tubers are usually consumed within a short distance of their cultivation. This ease of handling of grain crops probably accounted for the rise of larger and more complex grain based societies compared to ones dependent on tubers, with traded grain becoming the life blood of civilisation.

Growing grain in the humid subtropics presents some challenges, made far more difficult by the highly variable climate in Australia. This unpredictable weather now seems to be spreading to other parts of the world. Grain growing in Australia has always been on an industrial scale, allowing long periods of drought and crop failures to be weathered by the ease of importing grain from elsewhere on the global market. Closer to the coast grains are challenging because it is often too dry to sow them at the correct time of year, and often too wet to harvest them without losses to rot when they are mature. Maize for example only produces a crop about half the time for example. Tuber crops are generally superior as they are more flexible about planting and harvest timing. Many grains also experience devastating pest pressure due to our dozens of different bird species and periodic rat and mouse plagues. This factor alone has eliminated the majority of grains I have trialled from contention.

One of the few grain crops that seems to overcome most of these issues is grain amaranth. This stately plant produces tiny seed about the size of a flea that is rich in well balanced protein and minerals. It also contains a fair amount of oxalate so should be soaked and cooked thoroughly and eaten in moderation. I usually cook it by the absorption method after soaking for 12 hours to produce a kind of porridge. It can also be popped to produce tiny puffs, which were combined with human blood to create ritual figurines. There is a great art and craft idea if you have a kid you want to get rid of to please the sun god. The crop requires some moisture to get started but on decent soil can usually continue even if conditions start turning dry part way through growth. I normally sow during the start of summer rainy season to mature in late autumn. The seed can be scattered on the surface of broken up soil surfaces, such as created by a roughly hoed row, or in a pen recently visited by livestock. The seed seems to be particular about the type of soil it will germinate in. I suspect it can detect the levels of nitrate in the soil since they germinate most readily on aged fertilised soil or places where fire recently occurred.

There is a fairly wide diversity of genetics in circulation for grain amaranth if you look for it. Its status as a non-commercial crop means it is usually easy to import the seed, unlike major crops with serious pest and disease issues for quarantine to worry about. Yield, colour and stature varies quite a lot, with a dwarf variety in trials many years ago giving about twice the yield of its taller cousins. I decided to not grow this variety though since it requires perfect weeding under my conditions. My preferred variety, Hartmans Giant, is a monster that gets to 2 m tall when happy. This makes it a perfect companion for maize, quickly creating a weed suppressing canopy under suitable conditions. Leaf amaranth varieties are also around, but I find them to be too rich in oxalate for my tastes (plus they have a weird papery texture).

The yield from the crop is never much compared to true staple grains, and this probably accounts for why it is rarely grown commercially. A similar area of healthy maize would produce five times as much calories easily. From a strong crop of around 100 square meters interplanted with maize I yielded about 5 kg of grain, about 78 000 kJ or about a week’s worth of human food energy. Instead it is important to see grain amaranth as a great complementary crop to maize. For one thing maize is great at producing calories, but not much else. People eating nothing but maize quickly encounter nutritional deficiencies. Adding a moderate amount of grain amaranth to the diet can help balance that out. Another complementarity is in their growing rhythm. Large maize seeds need to be sowed individually, a fairly labour intensive process. When seeds fail to establish they leave a gap in the planting, that resowing normally won’t work on since that particular maize plant will be trailing behind all its siblings. Instead if amaranth is lightly scattered around at the same time maize is sowed it can grow to fill in these gaps, producing stronger plants where the space is available. Thinning excess seedlings to every 30 cm apart is a good idea since it is much easier to harvest and process a small number of larger plants.

Another huge advantage of grain amaranth is the very simply processing and storage, requiring no specialised equipment, unlike most other grains. The main difficulty is knowing when to harvest the crop, since the seed are so tiny and held in tiny capsules with a lid that pops off when mature. The seed doesn’t mature uniformly, so you need to time harvest carefully for when the oldest seed hasn’t fallen out but the youngest seed is mature enough to be extracted. When heads are still flowering tiny anthers can be seen poking from the heads, starting at the bottom of each spikelet and moving toward the tip over time. When the last anthers disappear harvest time is coming soon. I then check my heads by gently pressing between my hands and observing how many seeds are dislodged and where on the spike. Once the lowest capsules in the spike release easily it is time to harvest. The heads can be hung to dry to give the youngest seeds time to mature a little more. I then rub the heads between my hands to pop as many capsules as possible, then thresh in a container. Setting up a sheet either side can be useful to catch seed that fly off in other directions. Putting a metal grating (like a weldmesh panel) over the container can help to distribute threshing pressure over the head. The resulting material will contain seeds, capsule tops, pieces of flowers and usually lots of diverse bugs. I roughly shake the container to get the larger pieces to move to the top then remove them by hand. Leaving the container in a bright spot can help encourage the bugs to move along. I then run the mixture through a fine kitchen sieve, which removes the last of the large pieces and tends to retain some of the capsule tops as long as you don’t shake the sieve for too long. The grain will still contain capsule tops and other fine debris. It is then time to get two large containers and wait for a nice breeze to winnow the grain. Pour the grain mixture from one container to another, watching the stream so the heavier grain lands in the second container while the dust and debris blows away. You can adjust the height of the pouring container, starting close then moving further up while watching the position of the grain and debris streams, to control the stream in response to the strength of the breeze. On a windier day you can keep the pouring container closer to the receiving one. After a couple dozen passes the grain should be clean. I prefer to leave it out in a dry and shady place to air dry. Unlike other grains amaranth is fairly resistant to fungal issues while drying down, but spreading it on a sheet or piece of newspaper is a good way to reduce the risk. Grains release a lot of moisture as they dry so putting them in too thick a layer against plastic or metal is a recipe for mould. Grain for consumption can then be dried more thoroughly in a slow oven, which also kills off any residual insect eggs and helps with long term storage. Grain for sowing can be stored in an open container at room temperature without much loss in viability, or put through standard seed saving procedures.

Growing, processing and cooking with grains is one of the most complex of human endeavors, and also one of the most vital ones if we wish to live in societies that are more than clusters of mud huts. Determining which species, which varieties and which techniques can reliably produce staple grains on a meaningful scale in your precise conditions takes many years of experimentation. Best to start now if you can at a time when failure doesn’t mean starvation.

A sample of stored grain amaranth, a mix of my pale seeded Hartman giant and another black seeded purple leaf strain. Table spoon for scale.
This year’s crop of Hartman’s giant getting close to harvest time.

One thought on “Plant Profile- Grain Amaranth

  1. I’ve grown both grain and leaf amaranth but grew the grain only once and didn’t do anything with the seed. I don’t think there was much anyway. I didn’t like the taste of the leaf amaranth so gave that a miss as a food crop, but it still comes up everywhere each year. I thought the chooks might like the seeds, so I collect them, but being black and so tiny, they don’t seem to see them on the ground and it gets quickly buried by their scratching. Maybe I’ll try grain amaranth again. I didn’t know it had to be soaked, so I need to do some research. Maybe the chooks will see the light-coloured seeds and I can put any excess in my bread. If it comes up everywhere like the leaf variety it will be a bonus. Every bit helps.


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