Boosting Microgreens’ Nutrient Content: What Works.

Microgreens start out rich in vitamins and plant compounds. Can a grower push those levels higher? Yes, within limits. Light, feeding, a pinch of salt and a few plant extracts have all moved the numbers in trials.

But the gains are smaller and patchier than the big claims online. A change that helps one crop can do nothing for the next, or cost you yield. Here’s what the studies found, method by method.

What does boosting nutrients in microgreens mean?

It means growing the tray so the harvest holds more of something useful. That might be vitamin C, carotenoids or the color compounds called anthocyanins. It can mean less of something, too, like nitrate.

Growers have three main levers. They can change the light. They can change what goes in the water. Or they can add a mild stress, like a little salt or a plant extract, that nudges the seedling to make more defense compounds.

Adding minerals like zinc, iron or selenium to the water is its own topic. Our entry on microgreens biofortification covers those trials and where the dose gets risky. This entry covers the other levers.

One rule runs through all of it. Nearly every trial found the response depends on the crop. Researchers say “species-specific” so often it’s almost a refrain.

How does light change the nutrients in microgreens?

More than almost anything else a grower controls. Light sets how fast the plant grows, and it shapes what the plant makes.

Brightness. Cabbage and Chinese kale microgreens were grown under four light levels. Cabbage did best at the brightest setting, with more vitamin C, carotenoids and chlorophyll. Chinese kale peaked one step lower. A 14 to 16 hour day gave the best results for both (Liu et al., 2022).

Color. In arugula, kale and mustard microgreens, LEDs with 20% blue light gave the most vitamin C. Pushing blue to 30% gave the most anthocyanins in every crop tested but mustard (Ying et al., 2021).

Hours. Rapini microgreens grown under light around the clock doubled their yield. They held 67% more anthocyanins, nearly three times the flavonoids and half the nitrate of trays on a 16-hour day. Just two to three days of nonstop light before harvest gave much of that gain (Shibaeva et al., 2025).

Light can cut nitrate as well. Purslane microgreens under red and blue LEDs held 81% less nitrate than trays under fluorescent tubes (Giménez et al., 2021). For setups and light levels, see our microgreens lighting guide.

Shelf-style T5 LED strips are a common way to light a rack of trays at home.

Do microgreens need fertilizer to be nutritious?

For yield, often yes. For nutrients, it’s not so simple. In the video above, On The Grow fed one tray of broccoli microgreens a hydroponic nutrient and watered another with plain tap water. The fed trays grew faster and weighed more at harvest.

A peat-based trial found the flip side. Three brassica microgreens were grown with and without added nutrients. Skipping the feed cut nitrate sharply in all three. It cut rocket (arugula) yield by 47%, but rocket gained 58% more vitamin C and 110% more lutein. Cabbage gained 30% more vitamin C and lost only 10% of its yield (El-Nakhel et al., 2021).

Brussels sprouts microgreens gained nothing from going unfed. So feeding is a trade. It buys weight, and in some crops it costs a share of the compounds you grew them for.

Want to repeat On The Grow’s test on your own trays? This is the nutrient they used.

Can a little salt make microgreens more nutritious?

A little, sometimes. Mild salt is a stress the plant answers by making more protective compounds. Scientists call a helpful dose of stress eustress.

Wheat microgreens were watered with five salt levels. The lowest dose, 12.5 mM of salt, gave the most beta-carotene, vitamin C, flavonoids and phenolic acids. That’s about 0.7 grams of table salt per liter. Twice that dose gave the most anthocyanins and the highest antioxidant readings (Islam et al., 2019).

Other crops answer differently. Purslane microgreens watered with stronger salt water yielded more and held a little less nitrate. Their flavonoids, chlorophyll and carotenoids dropped (Giménez et al., 2021). In broccoli microgreens, salt at levels found in some tap water left yield alone and lowered vitamin C (Plocek et al., 2023).

Salt can work against the compound broccoli growers care about most. Broccoli microgreens given salt plus calcium sulfate held over three times less nitrate. Their sulforaphane fell as well (Zeng et al., 2022). For more on that compound, see the sulforaphane research hub.

Do seaweed and other biostimulants work on microgreens?

Some do, on some crops. A biostimulant is a product that nudges plant growth or chemistry without being a fertilizer. Seaweed extracts, plant extracts, protein blends and helpful microbes all fall under the label.

Seaweed. Arugula microgreens grown with an extract of the brown seaweed Ascophyllum nodosum gained 89% more flavonoids and 82% more antioxidant activity at a 2.5% dose (Drygaś et al., 2024). We found no microgreen trial showing that seaweed raises vitamin C.

The trial team made their own extract. If you buy one, look for Ascophyllum nodosum on the label, the species they tested.

Plant extracts. Three biostimulants, one of them a moringa leaf extract, cut nitrate by 27% in radish microgreens and raised phenolics by 19%. In turnip greens, one product shrank the plants by 19% (Toscano et al., 2023).

Seed priming. Soaking seeds in a plant protein solution before sowing raised antioxidant capacity in mibuna microgreens. It raised phenolic compounds in both mibuna and komatsuna, two Asian mustard greens (Ciriello et al., 2024).

Microbes. Pea microgreens sprayed with the fungus Trichoderma asperellum grew 140% more fresh weight. Paired with a Bacillus bacterium, it cut nitrate by about 40% (Pérez-Leal et al., 2025). That trial measured growth and pigments, not vitamins.

Does UV light or water stress raise healthy compounds?

UV light does, at a price. Flax microgreens given extra UV-B light made far more phenolics and flavonoids and had higher antioxidant capacity. The trade-off was size. They grew smaller, with shorter stems (Santin et al., 2022).

Water stress is a different story. You’ll read that holding back water for a few days raises sulforaphane by a big percentage. We found no microgreen trial that tested it. Until one does, treat that number as unproven.

Cool nights are in the same spot. Temperature shapes growth, and our post on what temperature and humidity microgreens need covers what’s been tested. We found no trial tying cool nights to more antioxidants in microgreens.

Boosting microgreen nutrients: what it all boils down to

You can grow a more nutritious tray. Light is the easiest place to start. In these trials, brighter light and more blue raised vitamin C and color compounds, and nonstop light doubled one crop’s yield.

Past that, every method is a trade. Salt, UV and skipping fertilizer can raise some compounds and cut weight or other nutrients. Biostimulants help some crops and not others. Change one thing at a time and judge it on your own crop.

Boosting microgreen nutrients: frequently asked questions

Which microgreen is the most nutritious?
It depends on the nutrient. A study tested 25 commercial microgreens. Red cabbage had the most vitamin C and cilantro the most carotenoids. Garnet amaranth led for vitamin K and green daikon radish for vitamin E (Xiao et al., 2012).

Is there a best nutrient solution for nutrition?
Not one that research backs. The trials here used different crops, media and mixes. In one, leaving out nutrients raised vitamin C in two of three crops and lowered yield.

Can you stack these methods?
Some trials paired two, like light color with salt, and saw both effects. Each added stress raises the chance of a smaller harvest, so add changes one by one and weigh each tray.

References

Want to go deeper? The Microgreens World research database holds 260 studies on how salt, light, heat and other stresses change microgreens. Search the papers →

Ciriello, M., Campana, E., Kyriacou, M. C., El-Nakhel, C., Graziani, G., Cardarelli, M., Colla, G., De Pascale, S., & Rouphael, Y. (2024). Plant‐derived biostimulant as priming agents enhanced antioxidant and nutritive properties in brassicaceous microgreens. Journal of the Science of Food and Agriculture, 104(10), 5921–5929. https://doi.org/10.1002/jsfa.13416

Drygaś, B., Piechowiak, T., Balawejder, M., Matłok, N., Kreczko, J., & Puchalski, C. (2024). The Eliciting Effect of Aqueous Extracts from Ascophyllum nodosum Algae on the Cultivation of Arugula (Eruca sativa Mill.) Microgreens. Sustainability, 16(17), 7436. https://doi.org/10.3390/su16177436

El-Nakhel, C., Pannico, A., Graziani, G., Kyriacou, M. C., Gaspari, A., Ritieni, A., De Pascale, S., & Rouphael, Y. (2021). Nutrient Supplementation Configures the Bioactive Profile and Production Characteristics of Three Brassica L. Microgreens Species Grown in Peat-Based Media. Agronomy, 11(2), 346. https://doi.org/10.3390/agronomy11020346

Giménez, A., Martínez-Ballesta, M. C., Egea-Gilabert, C., Gómez, P. A., Artés-Hernández, F., Pennisi, G., Orsini, F., Crepaldi, A., & Fernández, J. A. (2021). Combined Effect of Salinity and LED Lights on the Yield and Quality of Purslane (Portulaca oleracea L.) Microgreens. Horticulturae, 7(7), 180. https://doi.org/10.3390/horticulturae7070180

Islam, M. Z., Park, B.-J., & Lee, Y.-T. (2019). Effect of salinity stress on bioactive compounds and antioxidant activity of wheat microgreen extract under organic cultivation conditions. International Journal of Biological Macromolecules, 140, 631–636. https://doi.org/10.1016/j.ijbiomac.2019.08.090

Liu, K., Gao, M., Jiang, H., Ou, S., Li, X., He, R., Li, Y., & Liu, H. (2022). Light Intensity and Photoperiod Affect Growth and Nutritional Quality of Brassica Microgreens. Molecules, 27(3), 883. https://doi.org/10.3390/molecules27030883

Pérez-Leal, R., Rodríguez-Roque, M. J., Acevedo-Barrera, A. A., Villa-Martínez, A., Guerrero, B. I., Gutiérrez-Chávez, A., & Hernández-Huerta, J. (2025). Bacillus thuringiensis and Trichoderma asperellum as Biostimulants in Hydroponic Tendril Pea (Pisum sativum) Microgreens. Horticulturae, 11(1), 39. https://doi.org/10.3390/horticulturae11010039

Plocek, G., Kathi, S., & Simpson, C. (2023). Effects of eustress induced by low concentrations of salinity on broccoli (Brassica oleracea) and purslane (Portulaca oleracea) microgreens. Technology in Horticulture, 3(1). https://doi.org/10.48130/tih-2023-0004

Santin, M., Sciampagna, M. C., Mannucci, A., Puccinelli, M., Angelini, L. G., Tavarini, S., Accorsi, M., Incrocci, L., Ranieri, A., & Castagna, A. (2022). Supplemental UV-B Exposure Influences the Biomass and the Content of Bioactive Compounds in Linum usitatissimum L. Sprouts and Microgreens. Horticulturae, 8(3), 213. https://doi.org/10.3390/horticulturae8030213

Shibaeva, T. G., Rubaeva, A. A., Sherudilo, E. G., & Titov, A. F. (2025). Changing the Photoperiod at the End of the Production Cycle Allows to Increase the Productivity and Nutritional Value of Rapini Microgreens. Russian Journal of Plant Physiology, 72(3), 68. https://doi.org/10.1134/s1021443724609686

Toscano, S., Romano, D., & Patanè, C. (2023). Effect of Application of Biostimulants on the Biomass, Nitrate, Pigments, and Antioxidants Content in Radish and Turnip Microgreens. Agronomy, 13(1), 145. https://doi.org/10.3390/agronomy13010145

Xiao, Z., Lester, G. E., Luo, Y., & Wang, Q. (2012). Assessment of Vitamin and Carotenoid Concentrations of Emerging Food Products: Edible Microgreens. Journal of Agricultural and Food Chemistry, 60(31), 7644–7651. https://doi.org/10.1021/jf300459b

Ying, Q., Jones-Baumgardt, C., Zheng, Y., & Bozzo, G. (2021). The Proportion of Blue Light from Light-emitting Diodes Alters Microgreen Phytochemical Profiles in a Species-specific Manner. HortScience, 56(1), 13–20. https://doi.org/10.21273/hortsci15371-20

Zeng, W., Yang, J., Yan, G., & Zhu, Z. (2022). CaSO4 Increases Yield and Alters the Nutritional Contents in Broccoli (Brassica oleracea L. Var. italica) Microgreens under NaCl Stress. Foods, 11(21), 3485. https://doi.org/10.3390/foods11213485