The short version: Wheatgrass, or grain grass, is the young leaf of wheat, barley or oat, grown thickly in a shallow tray on damp mix and cut a centimetre above the mat at 10 to 15 cm, about 7 to 10 days from sowing. Soak the grain overnight, spread it in one dense single layer, keep it dark for two days, then give it bright light. It is a fast, cheap, sweet tasting indoor crop, and the health claims made for it run well ahead of the evidence.
Few crops go from dry seed to harvest inside a fortnight, on a kitchen bench, in any month of the year. Grain grass does. The growing is simple. The marketing around it is not.
What grain grass actually is
Grain grass is the young leaf of a cereal plant, cut long before the plant gets near making grain. Three are worth growing at home: Bread wheat (Triticum aestivum), Barley (Hordeum vulgare) and Oat (Avena sativa). Wheat is the one most people go looking for, and wheatgrass is simply its common name.
This is a tray crop, not a jar crop. In a jar you eat the lot, seed, root and shoot, as with broccoli and alfalfa sprouts. Nor is it a microgreen, cut at the seed leaf stage and eaten whole. Grain grass grows taller and is juiced, because the fibre in a grass leaf is cellulose, which humans have no enzyme to digest.
What you need
You need a shallow tray with holes, a second tray under it, 1 to 2 cm of seed raising mix or a coir mat, a third tray as a lid, sharp scissors and a spray bottle. Most of it is already in the house.
- A shallow tray with drainage holes over a second tray to catch water. A takeaway container with holes in the base will do
- About 1 to 2 cm of seed raising mix, or a coir mat cut to fit
- A third tray, upturned, as a lid for the first days
- Sharp scissors and a spray bottle
Soak, cover, then light
The method is four moves: soak, spread, cover, uncover. Soak the grain in cool water for 6 to 12 hours, at the short end in summer and the long end on a cold bench. It swells, the water goes cloudy, and that water is tipped out and the grain rinsed before sowing.
Fill the tray with 1 to 2 cm of seed raising mix, or lay the coir mat, then water it until it is damp right through and let it drain. Spread the drained grain thickly in a single layer on the surface and press it in gently. Do not cover it with mix. Grains should be touching but not piled up, grains touching but not piled up. A heap holds water in its middle, which is where trouble starts. Cover with the upturned tray and leave it dark for two days, three if the bench is cold. The shoots come up pale yellow and green within hours of reaching the light.
Water from below: pour into the catch tray, give the mix ten minutes to drink, then tip out whatever is left. Or mist twice a day. Damp but never sodden. Temperature sets the pace: the ideal band for wheat germination is 12°C to 25°C, and it still germinates between 4°C and 37°C, so a cold bench stretches the crop out rather than stopping it. Most trays are ready 7 to 10 days from sowing, at about 10 to 15 cm tall.
The first cut, and the truth about the second
Cut above the grain, roughly a centimetre above the mat, with sharp scissors and a fistful of grass in the other hand. Cutting lower drags husks and root into the juicer, and they taste like it. The tray smells like cut lawn while you work.
The first cut is the good one: sweet, strongly green, closer to sugar snap pea pods than to anything else in the kitchen, and best juiced within the hour.
A second cut is possible and usually thinner. Grass cut high and kept warm often comes again well, while a tray cut hard, or one that has spent what was stored in the grain, throws a sparse and grassier crop. Many growers sow again instead.
Wheat, barley or oat
The differences are real but modest, and flavour is the one you notice. Wheat is the default and the sweetest, with a thick juice. Barley runs sharper and more grassy. Oat is the mildest, and in the paddock the NSW Department of Primary Industries rates it the heaviest forage producer of the cereals.
What you should not choose on is a nutrition ranking. The only like for like tests are on stock forage, where NSW Department of Primary Industries reports no significant difference in protein, energy or digestibility between oat, wheat and barley grown under similar conditions. Nothing published ranks the juices. Heat is a tray problem more than a species problem: all three race away when warm, and the mat sours or dries before the grass is tall enough to cut.
Agriculture Victoria gives the test for telling them apart: seen from above, oat leaves twist anticlockwise while wheat and barley twist clockwise. More botany than most breakfasts require.
Oat grass for cats
Oat and wheat grass are what most cat grass actually is. The RSPCA notes that cats may benefit from access to grass, that chemically treated grass should be avoided, and that concerns have been raised about large amounts of certain cat grasses. Keep it modest, in clean mix. The cat will also sit in the tray, which no method prevents.
Mould on the mat
Mould is the commonest reason a tray fails. It is nearly always too much water, too much seed and too little air.
The panic tends to come at the wrong moment. A halo of fine white fuzz around the roots in the first days is root hairs: pure white, evenly spread around every root, no smell, and it vanishes when misted and returns as things dry. Real mould is patchy and uneven, often grey, blue-green or black, it stays visible when wet, and it smells musty. The same confusion turns up on seed trays in the garden.
- Rinse and drain the soaked grain well before sowing
- Sow one layer, not a mound, and tip out any standing water
- Leave a fan or open window nearby, and wash trays in hot soapy water between crops
If it is genuine mould, compost the mat and sow again rather than cutting the grass above it. Ten days and a handful of seed is a cheap thing to lose.
What the juice is, and what it is not
Wheatgrass juice is a green vegetable juice, and that is the honest description of it. It is fresh, it tastes strongly of sweet green things, and you grew it in a week.
The bigger claims do not hold up, and the research behind them is mostly small, much of it in the laboratory rather than in people, and the handful of human trials are tiny and have not been repeated. There is no good evidence that wheatgrass detoxifies the body or alkalises the blood, no strong evidence that it prevents or treats any disease, and the idea that its chlorophyll acts on the blood the way haemoglobin does is not supported. Equivalences of the one shot equals a plate of vegetables kind are marketing, not measurement. Some people also feel queasy after a first shot, so start small.
Food safety matters because the juice is drunk raw. Raw sprouts and sprouted seed have been linked to Salmonella and E. coli, and the warm damp tray that suits a germinating grain suits bacteria just as well. Most sprout outbreaks trace back to the seed rather than the kitchen, so start with untreated seed sold for sprouting or eating. Never use sowing grain or stockfeed, which is often dressed with fungicide and carries a label saying not to use it for human or animal consumption. After that, clean hands, clean trays, clean scissors, a cut well above the mat and juice drunk straight away cover it for most households. Food Standards Australia New Zealand lists raw seed sprouts among the higher risk foods for vulnerable people, so anyone pregnant, children under five, people over 70 and anyone immunocompromised should skip raw grain grass juice and eat sprouts cooked through.
Across Australia's climate zones
Grain grass grows indoors anywhere, so the zone question is how fast a tray dries and how fast mould takes hold on the bench.
In the Tropical zone (northern WA, the NT Top End and far north QLD) a Darwin bench in the wet is warm and saturated, so mould limits the crop rather than growth: sow thinly and run a fan. The Subtropical zone (south east QLD and northern NSW) does the same in a Brisbane summer and turns easy in winter. The Arid and semi-arid zone (inland NSW, SA, WA, central QLD and the southern NT) is the opposite, since an Alice Springs tray can dry to dust in half a day.
The Temperate zone (coastal and eastern NSW, VIC) is the easy middle, with Melbourne at its cold end. The Mediterranean zone (Perth and southern WA, Adelaide and southern SA) swings between the two: dry summers want arid zone watering, wet winters want airflow. In the Cool and alpine zone (TAS, the southern tablelands, the Victorian high country, and Canberra and the ACT) a winter bench in Hobart or Canberra sits below that ideal 12°C band, so give the tray extra days rather than extra water.
Wheat Grain Grass Sprout Seeds, Barley Grain Grass Sprout Seeds and Oat Grain Grass Seeds are all in the sprouting seeds range, with bulk sprouting seeds for a weekly tray. Due to quarantine restrictions and our shipping policy, we cannot send the grain grass seeds to Tasmania, and Western Australian orders go through Quarantine WA inspection, so allow a little extra time.
Frequently asked questions
How long does wheatgrass take to grow?
Most trays are ready 7 to 10 days from sowing, at about 10 to 15 cm tall. Warmth drives the speed, with the ideal band for wheat germination between 12°C and 25°C.
Can I get a second cut?
Often, yes, and it is usually thinner. Leaving a good centimetre of leaf at the first cut gives the plant something to regrow from.
Why has my tray gone mouldy?
Almost always too much water, too much seed or too little air. Sow a single layer, water from below, keep a fan nearby. If it is grey or blue-green and smells musty, compost it.
Is that white fuzz mould or roots?
Mist it and watch. Root hairs are pure white, evenly spread around each root, and vanish when wet before returning as things dry. Mould stays visible when wet and smells musty.
Can I eat the grass instead of juicing it?
You can chew it, but you will not digest much. The fibre in a grass leaf is cellulose, which humans have no enzyme to digest, so the juice goes in the glass and the fibre does not.
Is wheatgrass safe for people with coeliac disease?
The leaf itself is not the problem. Coeliac Australia's gluten free diet guide says barley grass and wheat grass do not contain gluten, because gluten sits in the grain rather than the blade. The problem in a home tray is the grain: sprouted wheat or barley a centimetre below the cut, and husks that ride up with a low cut. Cut high, keep grain and husk out of the juicer, or choose a tested product. Oats carry their own caveat for some people with coeliac disease, so the same applies to oat grass. Take your own medical advice.