Are microgreens safe to eat? What the research actually shows
The Microgreens World research database holds 140+ papers on microgreen safety. Here is what they tested, where the germs come from, who should take extra care, and where the evidence stops.
The short answer
- For most people, yes. A 2020 review found no illness outbreaks tied to microgreens. It did find seven recalls. Turner 2020
- The risk is real, and it usually starts with the seed. In lab trials, germs on seeds, in water or in growing mats spread into the leaves you eat. Xiao 2015 Işık 2024
- Microgreens grown from contaminated seeds carried far fewer E. coli than sprouts grown from the same seeds. Xiao 2014
- If you’re pregnant, older or have a weak immune system, take more care. Listeria is the germ that matters most for you.
- Skip borage microgreens. One study found a plant toxin at levels far above the EU limit. Sattler 2025
Has anyone gotten sick from microgreens?
Not in any outbreak on record, as of the 2020 review. But recalls happen, and they keep happening.
A 2020 review in the Journal of Food Science looked at the record. It found no outbreaks of foodborne illness tied to microgreens, and seven recalls Turner 2020. A recall means a germ was found, or might be there, so the product came off the shelf before anyone got sick.
Recalls in the US and Canada have named Listeria, Salmonella and E. coli Food Safety News. The biggest recent one hit Canada in May 2026. Microgreens from four brands came off the shelves, all traced to one bad lot of broccoli seed. No illnesses were reported Food Safety News 2026. I traced that one step by step in the 2026 Canadian recall post-mortem.
What about store shelves? Two studies bought microgreens and tested them.
| Where | What they tested | What they found | Source |
|---|---|---|---|
| Riga, Latvia | 45 samples of microgreens, sprouts and seeds | No Listeria monocytogenes. One sunflower seed sample had Salmonella. The authors called the microgreens generally safe. | Bergšpica 2020 |
| Store-bought microgreens | 122 samples | Salmonella turned up in sunflower and radish microgreens. | Xavier 2026 |
So the honest picture is this. Problems are rare, but they’re not zero.
Are microgreens safer than sprouts?
The best test we have says yes, by a wide margin. Sprouts have a much rougher history. About 25 years ago, the US FDA looked into 50 outbreaks and 2,600 cases of illness linked to sprouts Fahey 2022.
Same contaminated radish seeds, grown two ways
What they found
- The team put two kinds of harmful E. coli on radish seeds on purpose.
- Grown as sprouts, the E. coli grew to very high levels.
- Grown as microgreens, the same seeds carried far less. In plain terms, often a thousand times less, or more.
- The E. coli still grew in both. Microgreens were lower, not clean.
What it can’t tell you
- It was one crop, radish.
- The seeds were dosed with germs in a lab. Real seed lots are rarely that dirty.
- It measured germs on the plant, not illness in people.
Why the gap? You eat a sprout whole, seed and root included. Microgreens are cut above the growing mat. That helps, but it doesn’t make them clean. When seeds carried E. coli, it spread through the whole plant, leaves included, and the seed coat stayed the hot spot Xiao 2015. One research team put it plainly: treat microgreens the same way as sprouts when it comes to safety Wright 2018.
Where do the germs come from?
Most of the research lives here. Labs add germs to seeds, water or growing mats, then track where they end up. Here’s what they found.
| Source | What the study found | Source |
|---|---|---|
| Seeds | E. coli on seeds spread to the whole plant, leaves included. | Xiao 2015 |
| Seeds bought online | Of 102 seed samples from 14 crops, borage, carrot and onion seeds carried the most bacteria. | Ocho Bernal 2023 |
| Water | Dirty irrigation water put more E. coli on plants than dirty seeds did. | Wright 2018 |
| Hydroponic trays | Radish grown in water carried far more E. coli on the leaves than radish grown in peat. | Xiao 2015 |
| Growing mats | Salmonella and Listeria held steady for 10 days on hemp and Biostrate mats. They faded in coco coir and peat. | Misra 2020 |
| The crop itself | Sunflower picked up more germs than pea shoots. Across 20 crops, bigger, heavier seeds and longer grow times meant less transfer. | Deng 2021 Işık 2024 |
| Viruses | A stand-in for norovirus lasted all 10 days in growing mats. | Deng 2023 |
Who should take extra care?
Listeria is the germ to respect. It can grow in the cold, and it hits some people much harder than others: people who are pregnant, older adults, and anyone with a weak immune system.
Here’s what’s on paper. The CDC’s Listeria guide for pregnancy tells people to avoid raw or lightly cooked sprouts and to choose sprouts cooked until steaming hot CDC. It doesn’t mention microgreens. No study in the database has tested microgreens in pregnancy.
So what do you do? Microgreens aren’t sprouts, and the record is cleaner. But they share the same weak spot, the seed. If you’re in a higher-risk group, the cautious choice is the same step the CDC gives for sprouts: cook them until steaming hot, or talk with your doctor first. My kitchen guide, Can microgreens make you sick?, walks through it.
Washing and storing them at home
- Keep them cold. In one test, radish microgreens were washed and then stored at different temperatures. Above 10 °C (50 °F), Listeria grew fast from day one. E. coli took off above 15 °C (59 °F). The authors’ advice: keep them below 5 °C (41 °F) Choi 2020.
- A wash helps, but only so much. That same study used a chlorine wash, a commercial step and not a home one. It cut both germs by about 99 percent. Then the damaged leaves leaked juice, which helped germs regrow in warm storage Choi 2020.
- Germs hide in the leaf. Under the microscope, bacteria clung to tiny cracks and pores on microgreen leaves Xavier 2026. Rinsing can’t reach all of that.
The plain version: buy from a grower you trust, keep them in the fridge, and eat them within a few days.
Side effects and microgreens to skip
Borage: skip it
Borage makes natural toxins called pyrrolizidine alkaloids. In 106 borage leaf samples, the microgreens had the highest levels, on average 130 times the EU’s legal limit for borage leaves. The authors concluded that borage microgreens may not be fit to eat Sattler 2025.
Nitrate: high in most, and growers can lower it
Leafy plants store nitrate. In a test of 17 microgreen crops, all but sunflower landed in the high or very high range Di Gioia 2023. Growing choices move that number. Setting LED brightness in the right range Samuolienė 2013 and 24-hour lighting Shibaeva 2023 both lowered nitrate in cabbage-family microgreens.
What does that mean for your health? The papers here don’t answer it. None of them tested nitrate from microgreens in people.
The everyday downsides
Many people searching for side effects really want the catch. The research names two. Microgreens wilt, dry out and lose some nutrients soon after harvest. That short life keeps prices high Turner 2020. For the full list, see Pros and cons of microgreens.
What growers do to keep them safe
Selling microgreens, or buying from someone who does? These are the steps the research has tested.
| Step | What it did | Source |
|---|---|---|
| Seed soak in hydrogen peroxide, then dry heat | Cut microbes on seeds. Heat added more. Germination held up. | Ocho Bernal 2023 |
| Hydrogen peroxide plus peracetic acid, then heat | The best of the tested methods against Listeria on borage and carrot seeds. | Ayilaran 2026 |
| Chlorinated water spray during growth | Only a small drop in Salmonella and E. coli. | Işık 2022 |
| UV-C light after harvest | Big drops in all three germs. Some regrew in the fridge. | Işık 2026 |
How many growers do these things? A survey of 176 US growers found that small farms disinfected seeds more often than big ones. Bigger farms were more likely to test their growing media. Farms that kept records were more likely to pass a GAP audit Misra 2021. For the rules side, see what FSMA means for microgreens growers.
Grow microgreens to sell? The rules, the records and every grower article are on one page: food safety for microgreen growers. To see which documents you’re missing, take the five-minute gap assessment.
What the research doesn’t show yet
Here’s where the evidence runs out.
- Most studies are lab tests. Researchers add germs on purpose. Only a few studies have tested microgreens bought in stores Bergšpica 2020 Xavier 2026.
- No study has tested microgreens in pregnancy. The advice above borrows from what’s known about sprouts and Listeria.
- Viruses are barely studied. A 2025 review named viruses as a problem nobody has solved yet Xavier 2025.
- No one has set a safe daily amount. No study in the database tested how much is too much, for nitrate or anything else.
Key papers to start with
Eight papers that carry most of the weight on this page. Each title opens the paper at the publisher.
Microgreen nutrition, food safety, and shelf life: A reviewReview
No outbreaks tied to microgreens, seven recalls. The most cited safety paper in the database.
Comparison of the growth of Escherichia coli O157:H7 and O104:H4 during sprouting and microgreen production from contaminated radish seeds
Same seeds, two ways. Microgreens carried far less E. coli than sprouts.
Proliferation of Escherichia coli O157:H7 in soil-substitute and hydroponic microgreen production systems
Seed germs spread through the whole plant. Hydroponic trays carried more than peat.
Quantification and colonisation dynamics of Escherichia coli O157:H7 inoculation of microgreens species and plant growth substrates
Nine crops tested. Dirty water was worse than dirty seed.
Transfer of Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes from contaminated soilless substrate and seeds to microgreens
Twenty crops. Bigger seeds and longer grow times meant less transfer.
Microbiological quality of microgreen seeds purchased from online vendors and evaluating seed decontamination techniques available online
102 online seed samples tested, plus the home seed soaks people share online.
Characterization of microgreen growing operations and associated food safety practices
The first national survey of US microgreen growers and their safety habits.
Pyrrolizidine alkaloid contents and profiles in Borago officinalis leaves, flowers and microgreens: Implications for safety
Borage microgreens averaged 130 times the EU limit for a natural plant toxin.
Newest papers on this topic
- Newest papers load from the research database.
Questions people ask
Are microgreens safe to eat?
For most people, yes. A 2020 review found no illness outbreaks tied to microgreens, though it counted seven recalls. Lab studies show germs on seeds, in water or in growing mats can reach the leaves, so how they’re grown and stored matters.
Can microgreens make you sick?
They can carry Salmonella, E. coli or Listeria, the same germs found on other raw greens. Recalls have happened in the US and Canada. No outbreak was tied to microgreens in a 2020 review of the record.
Are microgreens safer than sprouts?
In a head-to-head lab test, microgreens grown from contaminated radish seeds carried far less E. coli than sprouts grown from the same seeds. They weren’t clean, just lower. Sprouts have a much longer outbreak history.
Are microgreens safe during pregnancy?
No study has tested microgreens in pregnancy. The CDC tells pregnant people to avoid raw sprouts and choose sprouts cooked until steaming hot. Microgreens aren’t sprouts, but they share the same seed risk. Cooking them or asking your doctor is the cautious path.
Should you wash microgreens?
A rinse can’t reach germs hiding in the tiny cracks and pores of a leaf. Cold storage matters a lot. In one study, Listeria grew fast on radish microgreens above 10 °C (50 °F). The authors advised keeping them below 5 °C (41 °F).
Which microgreens should you not eat?
Skip borage. Borage microgreens carried a natural plant toxin at about 130 times the EU limit for borage leaves, on average, in a 2025 study.
What are the disadvantages of microgreens?
They wilt and lose some nutrients soon after harvest, and that short life keeps prices high. Most crops tested are high in nitrate. And like any raw green, they can carry germs if the seed, water or growing mat is contaminated.
Keep reading
Sources
- Turner, Luo & Buchanan (2020). Microgreen nutrition, food safety, and shelf life: A review. Journal of Food Science. doi.org/10.1111/1750-3841.15049
- Xiao, Nou, Luo & Wang (2014). Comparison of the growth of Escherichia coli O157:H7 and O104:H4 during sprouting and microgreen production from contaminated radish seeds. Food Microbiology. doi.org/10.1016/j.fm.2014.05.015
- Xiao, Bauchan, Nichols-Russell, et al. (2015). Proliferation of Escherichia coli O157:H7 in soil-substitute and hydroponic microgreen production systems. Journal of Food Protection. doi.org/10.4315/0362-028x.jfp-15-063
- Wright & Holden (2018). Quantification and colonisation dynamics of Escherichia coli O157:H7 inoculation of microgreens species and plant growth substrates. International Journal of Food Microbiology. doi.org/10.1016/j.ijfoodmicro.2018.02.025
- Işık, Çetin & Topalcengiz (2024). Transfer of Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes from contaminated soilless substrate and seeds to microgreens. International Journal of Food Microbiology. doi.org/10.1016/j.ijfoodmicro.2024.110612
- Ocho Bernal, Lyttle & Jung (2023). Microbiological quality of microgreen seeds purchased from online vendors and evaluating seed decontamination techniques available online. Frontiers in Sustainable Food Systems. doi.org/10.3389/fsufs.2023.1264472
- Misra & Gibson (2020). Survival of Salmonella enterica subsp. enterica serovar Javiana and Listeria monocytogenes is dependent on type of soil-free microgreen cultivation matrix. Journal of Applied Microbiology. doi.org/10.1111/jam.14696
- Deng, Misra, Baker & Gibson (2021). Persistence and transfer of foodborne pathogens to sunflower and pea shoot microgreens during production in soil-free cultivation matrix. Horticulturae. doi.org/10.3390/horticulturae7110446
- Deng & Gibson (2023). Persistence and transfer of Tulane virus in a microgreen cultivation system. International Journal of Food Microbiology. doi.org/10.1016/j.ijfoodmicro.2022.110063
- Misra & Gibson (2021). Characterization of microgreen growing operations and associated food safety practices. Food Protection Trends. doi.org/10.4315/1541-9576-41.1.56
- Ayilaran, McHugh & Jung (2026). Microgreen seed decontamination: Efficacy of hydrogen peroxide, hydrogen peroxide-peroxyacetic acid, and dry heat against Listeria monocytogenes. Journal of Agriculture and Food Research. doi.org/10.1016/j.jafr.2026.102882
- Işık, Aytemiş, Çetin & Topalcengiz (2022). Possible explanation for limited reduction of pathogens on radish microgreens after spray application of chlorinated water during growth. Journal of Food Safety. doi.org/10.1111/jfs.12984
- Işık, Çetin, Moreira & Topalcengiz (2026). Post-harvest UV-C treatment of microgreens for inactivation of Salmonella enterica, Escherichia coli O157:H7 and Listeria monocytogenes. Foods. doi.org/10.3390/foods15060974
- Choi, Chu, Rajalingam, et al. (2020). Growth of Escherichia coli and Listeria monocytogenes on radish microgreens washed with sodium hypochlorite during storage. Korean Journal of Food Preservation. doi.org/10.11002/kjfp.2020.27.7.850
- Xavier, Viana, Perim, et al. (2026). Salmonella in microgreens: quantitative modeling of Salmonella Enteritidis in a controlled environment system. Food Research International. doi.org/10.1016/j.foodres.2026.119209
- Bergšpica, Ozola, Miltiņa, et al. (2020). Occurrence of pathogenic and potentially pathogenic bacteria in microgreens, sprouts, and sprouted seeds on retail market in Riga, Latvia. Foodborne Pathogens and Disease. doi.org/10.1089/fpd.2019.2733
- Sattler, Huch, Bunzel, et al. (2025). Pyrrolizidine alkaloid contents and profiles in Borago officinalis leaves, flowers and microgreens: Implications for safety. Food Control. doi.org/10.1016/j.foodcont.2024.110930
- Di Gioia, Hong, Pisani, et al. (2023). Yield performance, mineral profile, and nitrate content in a selection of seventeen microgreen species. Frontiers in Plant Science. doi.org/10.3389/fpls.2023.1220691
- Shibaeva, Rubaeva, Sherudilo & Titov (2023). Continuous lighting increases yield and nutritional value and decreases nitrate content in Brassicaceae microgreens. Russian Journal of Plant Physiology. doi.org/10.1134/s1021443723601337
- Samuolienė, Brazaitytė, Jankauskienė, et al. (2013). LED irradiance level affects growth and nutritional quality of Brassica microgreens. Open Life Sciences. doi.org/10.2478/s11535-013-0246-1
- Fahey, Smilovitz Burak & Evans (2022). Sprout microbial safety: A reappraisal after a quarter-century. Food Frontiers. doi.org/10.1002/fft2.183
- Xavier, Tavares, Pontes, et al. (2025). Understanding food safety on sprouts and microgreens: Contamination routes, outbreaks and challenges. Food Research International. doi.org/10.1016/j.foodres.2025.116589
- Centers for Disease Control and Prevention. Protect your pregnancy from Listeria (fact sheet). cdc.gov/listeria/pdf/protect-your-pregnancy-h.pdf
- Food Safety News. Microgreens recall archive. foodsafetynews.com/tag/microgreens
- Food Safety News (May 2026). Microgreens recalled in Canada because of E. coli contamination. foodsafetynews.com/2026/05/microgreens-recalled-in-canada-because-of-e-coli-contamination
Read the papers yourself
Every paper behind this page sits in the Microgreens World research database. Open any one to read its abstract and go straight to the full text.
Search the safety papersThis page summarizes published research for education. It is not medical advice and is not meant to diagnose, treat, cure or prevent any disease. Talk with a qualified health professional about your own health, especially if you are pregnant or have a weak immune system.
