Microgreens Claims

What popular sites say

Hydroponic growing uses no soil, so it lowers the risk of contamination.

Found on 1 site in our collection

What the evidence says

Taking the soil away does not by itself make microgreens safer. USDA researchers grew radish microgreens from seed carrying E. coli O157:H7, in peat and in a hydroponic system. The germ grew in both. It reached much higher levels on the hydroponic plants. Contaminated seed is the main risk with soil or without it.

What popular sites say

Coconut coir has just the right nutrients for microgreens.

Found on 1 site in our collection

What the evidence says

Coir is not a balanced plant food. Lab tests on 13 coir dusts from three continents found low levels of available nitrogen, calcium, magnesium and trace elements, with excess salts in some. In microgreen trials on coconut fiber, researchers fed the plants a nutrient solution.

What popular sites say

Sixteen small-seeded crops, such as arugula, broccoli, radish and kale, should never be soaked.

Found on 1 site in our collection

What the evidence says

Small seeds do not need a soak. No study shows a soak hurts them, though. In radish trials from Brazil and Indonesia, soaking seed before sowing did not lower emergence or yield. For amaranth and kale, a seed priming method (not a plain soak) raised shoot weight. Most crops on the list, like arugula, lettuce and mustard, have never been tested.

What popular sites say

Beet seed should not be soaked before planting.

Found on 1 site in our collection

What the evidence says

Soaking beet seed did no harm in a controlled study. Water soaks of 12 to 48 hours made the seed sprout faster. Longer soaks worked faster still, and final germination stayed about the same. Chard may be different. Soaked chard seed trended toward lower germination in the same study.

What popular sites say

A short soak in diluted household bleach kills all the bacteria and mold on sunflower seed hulls.

Found on 1 site in our collection

What the evidence says

Chlorine washes cut germs on seed. They do not kill all of them. In lab tests on alfalfa seed, chlorine washes far stronger than a home bleach mix cut Salmonella and E. coli O157:H7 by about 99%. Some germs survived every time. An FDA review agrees. The standard seed wash lowers contamination but does not remove it.

What popular sites say

Sunflower and tendril pea seed must be soaked before sowing.

Found on 1 site in our collection

What the evidence says

Soaking is optional. In an Indonesian trial, unsoaked sunflower seed sprouted at nearly the same rate as soaked seed (about 77% against 78 to 80%). Soaks of 6 to 12 hours gave a little more weight. In a Mississippi State trial on ten microgreens, pea among them, a 6-hour soak did not raise yield. In one of two runs it lowered shoot weight. Extension guides suggest a soak for these crops. They do not say it is required.

What popular sites say

Chard should not be grown hydroponically.

Found on 1 site in our collection

What the evidence says

Swiss chard microgreens grow well in hydroponics. An Italian trial grew basil, Swiss chard and rocket in a hydroponic system. Chard gave the highest fresh yield of the three and was ready to cut 17 days after sowing.

What popular sites say

Keep indoor microgreens out of direct sunlight.

Found on 1 site in our collection

What the evidence says

Extension advice says the opposite. Illinois Extension suggests six to eight hours of light and prefers a sunny, south-facing window. Oregon State Extension says to use a bright window or a lamp. Dim light makes plants leggy. Neither source warns against direct sun.

What popular sites say

Nutrient solutions need pure or distilled water. Minerals in tap water push the pH up.

Found on 1 site in our collection

What the evidence says

You do not need distilled water. Oklahoma State extension says to have your source water tested, then fill the tank with tap or filtered water. The site is right on one point. Water with alkalinity above about 75 ppm pushes pH up, and acid or reverse osmosis can correct it.

What popular sites say

Garden, microgreen and sprouting seed differ only in the packet instructions and seed count.

Found on 1 site in our collection

What the evidence says

The differences go deeper than the packet. Garden seed is often coated with fungicide, and treated seed must never be eaten. UF/IFAS says not to use treated seed for microgreens. FDA counts seed for sprouting as food. It expects more food-safety care in producing that seed than seed for other uses. Untreated garden seed of the same variety can be the same seed. That part of the claim holds.

What popular sites say

A list of 19 crops, from broccoli and kale to orach and fava bean, is given as the most common vegetable microgreens.

Found on 1 site in our collection

What the evidence says

Most crops on the list are real microgreen crops. Several are not common. In a 2021 survey of 143 US growers, the crops grown most were radish, sunflower, pea shoots, arugula, broccoli and kale. Turnip, cauliflower, orach, fava bean, Brussels sprouts and lettuce were not among the crops named. UF/IFAS adds that lettuce is usually left out.

What popular sites say

Seeding density changes lettuce growth, leaf size and plant size a lot, unlike regular microgreens.

Found on 1 site in our collection

What the evidence says

Density matters for lettuce. It matters for other microgreens too. A lettuce trial found thicker sowing changed plant height and fresh weight. Trials on six other species and on arugula found the same pattern. Thicker sowing gave more yield per tray but smaller, lighter single plants.

What popular sites say

Sulforaphane in broccoli peaks during the 10 to 14 day microgreen stage.

Found on 1 site in our collection

What the evidence says

Not by concentration. Glucoraphanin, the plant compound that becomes sulforaphane, is most concentrated in seeds and young sprouts about 1 to 3 days old. It falls as the seedling grows. Three-day sprouts had 10 to 100 times more than mature plants. The total amount per seedling can keep rising for weeks, as the plant gets bigger.

What popular sites say

Beans and lentils can only be eaten as sprouts, and borage, sunflower and beet can’t be grown as sprouts.

Found on 1 site in our collection

What the evidence says

Beans and lentils are grown and eaten as microgreens too. Researchers in India grew lentil and mung bean microgreens and found the best harvest day for lentil was about day 9. Another study measured the nutrients in bean microgreens.

What popular sites say

Hardy crops like sunflower and pea shoots can last a month or longer after harvest.

Found on 1 site in our collection

What the evidence says

No study shows that. The longest tested storage for sunflower microgreens was about 16 days, kept at 10 °C in packed trays with added treatments. We found no shelf-life study on pea microgreens. A review describes microgreens as quick to wilt and decay after harvest.

What popular sites say

In most places you can sell microgreens under cottage food laws, as they are non-perishable.

Found on 1 site in our collection

What the evidence says

Raw microgreens count as fresh produce, not cottage food. In Minnesota and Tennessee, produce you grow needs no cottage food registration or food license. Microgreens are not non-perishable. Storage studies show they last about 1 to 2 days at room temperature.

What popular sites say

A microgreens business run from home can start in a few square feet for $700 to $1,000.

Found on 1 site in our collection

What the evidence says

One extension budget comes in much higher. A 2024 University of Missouri Extension budget lists $4,384 in startup costs for one shelf system, or $1,884 without a $2,500 cooler. Lights and trays alone come to about $1,250 in that budget.

What popular sites say

The global microgreens market was forecast to reach USD 17.04 billion by 2025.

Found on 1 site in our collection

What the evidence says

Market reports with stated methods put the 2025 market at about USD 1.9 to 3.3 billion. The $17 billion figure shows up in a 2025 review that cites another secondary source. It is about five times higher than any of the method-based estimates.

What popular sites say

Farmers market customers pay cash about 25% of the time and by card about 75%.

Found on 1 site in our collection

What the evidence says

A 2025 survey says the reverse. Of 1,039 US shoppers, 76% said they usually pay cash at farmers markets. About 40% said they regularly use cards.

What popular sites say

Hydrogen peroxide is the only mold treatment allowed in organic farming.

Found on 1 site in our collection

What the evidence says

It is one of many. The USDA National List allows hydrogen peroxide for crop disease control, and it lists ten other synthetic options next to it. Those include copper products, hydrated lime, lime sulfur, horticultural oils, peracetic acid, potassium bicarbonate and sulfur. Natural and biological materials are allowed too, if not banned.

What popular sites say

Several sites give how-to tips for borage microgreens, such as seeding rates, blackout days and harvest timing.

Found on 2 sites in our collection

What the evidence says

A 2024 study tested 106 borage leaf samples, microgreens included. Borage microgreens held very high levels of pyrrolizidine alkaloids, natural plant toxins. On average they were 130 times over the EU legal limit for borage leaves. Levels dropped as plants matured. The authors concluded borage microgreens may not be fit to eat.

What popular sites say

Raw bulk sunflower seed from the grocery store is safe for microgreens but may sprout poorly.

Found on 1 site in our collection

What the evidence says

We found no source that says grocery seed is safe to grow as microgreens. FDA guidance says seed for sprouting calls for more food-safety care than seed meant for other uses. So "safe" can’t be confirmed. No one has tested how well grocery seed sprouts, either.

What popular sites say

Do not grow nightshades like tomato, pepper, eggplant and potato as microgreens. Some sites add that the seedlings hold toxic solanine.

Found on 3 sites in our collection

What the evidence says

Extension services at the University of Illinois and NC State advise against nightshade microgreens. Tomato, potato and eggplant leaves contain natural toxins called glycoalkaloids. Solanine is the potato one. Tomato and eggplant make related compounds. No study has measured them at the microgreen stage. Pepper leaves have not been shown to carry them.

What popular sites say

Nightshades, rhubarb, ornamental sweet peas and chemically treated seed are never safe as microgreens. Bird seed and feed are not handled to food-safety standards.

Found on 1 site in our collection

What the evidence says

Oregon State Extension says rhubarb leaves are toxic and should never be eaten. NC State Extension lists ornamental sweet pea seeds as poisonous. A 1974 study found a lathyrogen, a compound tied to the disease lathyrism, in sweet pea seedlings. US seed law says treated seed with harmful residues must carry a "Do not use for food" warning. Rhubarb chard is a beet relative and a different, safe crop.

What popular sites say

Several sites suggest misting or spraying seeds and trays with a homemade hydrogen peroxide mix to stop mold, some of them daily for several days.

Found on 2 sites in our collection

What the evidence says

No study shows these sprays control mold on microgreens. The one microgreen spray trial sprayed arugula, radish and sunflower once a day from seed to harvest, at 0 to 200 mg per liter. It looked at leaf damage only, not mold. Leaf damage started at the lowest level tested (25 mg per liter) in arugula and radish. Sunflower showed no damage, and plant weight did not change in any crop. The mixes sites suggest are many times stronger than anything tested on leaves, so crop safety at those strengths is unknown too.

What popular sites say

Food-safe seed is tested for pathogens, bird seed is not, and bird seed may be chemically treated.

Found on 1 site in our collection

What the evidence says

Seed sold for sprouting is meant to be grown and stored with stricter food-safety care than other seed. Some suppliers test seed lots for germs, but FDA says testing is optional. A clean test does not prove the seed is clean, as tests often miss pathogens. Ontario’s food safety page tells growers to ask the supplier for a pathogen test certificate for each lot. We found no source on testing or treatment of bird seed.