Mint microgreens

Forty-two entries into this directory, exactly one of them told you not to black out the tray. Mint is the second and the strictest of what is now three, with purslane added on 2026-08-09: lettuce tolerates twelve to twenty-four hours under a dark cover, while the one crop-specific mint guide reports minimal or no germination when mint seed is covered at all. Mint seed needs light to start. It also needs to sit on the surface, unpressed and unweighted, for the ten to twelve days it can spend nearly invisible.

That is one of the two things worth knowing about this crop. The other is that the only seed rate anybody publishes for it, 14 grams a tray, would put roughly 154,000 seeds into a 1020, which is about ten times the densest sowing any published microgreen study has measured. This page will not print that number in the comparison table, and the arithmetic for why is at the bottom.

What it is, and how to tell you grew it right

Mint microgreens are seedlings of Mentha spicata, spearmint, in the Lamiaceae. That makes them the second crop in this directory from the same family as basil, and the two share the family's tray problem: fine seed, slow start, and a schedule set by a herb rather than by a brassica.

"Mint" is not one plant and the seed shelf proves it. A specialist microgreen seller separates spearmint from peppermint, Mentha x piperita, and calls the peppermint types darker and more menthol-intense; "Chocolate" and "Black" mint belong to that group. Those are different plants sold under the same three-letter word, not grades of one thing. This page is about spearmint, because spearmint is the sweeter, softer one that a chef actually wants on a dessert.

Beyond the two true mints, the same searches return several plants that are not Mentha spicata at all: Corsican mini mint, which is Mentha requienii and sold as a drought-tolerant ground cover; mountain mint, a Pycnanthemum wildflower; lemon mint, which is Monarda; apple mint; and perilla, sold under the label "Asian mint", which is the plant this directory will eventually cover as shiso. Six different genera answer to the word.

At harvest, expect a low, sparse, delicate stand rather than the dense upright canopy of a brassica. The best crop-specific description available calls the leaves soft and velvety with light pubescence, the fine hairs you can see when the light catches them side on. **Millimeter heights, stem color and stand evenness for a M. spicata microgreen tray are not published anywhere**, and image searching found real spearmint seedling trays but no authenticated microgreen-harvest photograph, so this page does not invent dimensions for them. Mature spearmint reference material describes bright green, spear-shaped, serrated leaves, which is the adult plant and not what you cut.

The honest confusion warning is that you cannot tell spearmint from peppermint by looking at a seedling. The separation the sources support is sensory: spearmint reads sweeter and softer, peppermint reads colder and sharper. Anyone promising a leaf-color tell at cotyledon stage is guessing, which is the same verdict this directory reached for komatsuna against its Brassica rapa siblings.

What it tastes like, and what to do with it

Sweet, cooling and clean, with the menthol dialled well below peppermint's. It is the mint of a mojito and of lamb sauce rather than the mint of a candy cane.

That decides the quantity. Mint is a finishing herb measured in leaves, and it goes where a tiny amount of aroma does real work: whole leaves on panna cotta or ice cream, through a fruit salad, on lamb, in Vietnamese-style fresh rolls, in lime water, lemonade or a cocktail. It is a garnish crop in the strict sense, which is unusual here. Most entries in this directory argue about ounces per tray because most of these crops are eaten by the handful. Nobody eats a handful of mint.

Two uses are wrong and the crop-specific source says so. Heat destroys it: hot food drives off the aroma and darkens the leaf, so it goes on after the pan comes off or not at all. And it is a poor partner for garlic, chile and heavily spiced dishes, which simply cover it. If your menu is built on those, this tray is a waste of the bench.

People who dislike menthol will dislike this, and there is no growing technique that fixes it. So will anyone hoping for a neutral crunchy salad green, which mint is not at any density.

Growing it: only what differs from the standard method

Everything general about trays, medium, light and watering is on the standard tray method for growing microgreens. Almost every mint-specific instruction is a subtraction from it.

Do not black it out, and this is the whole crop. Mint seed needs light. The crop guide reports minimal or no germination when the seed is covered, and a seed supplier specifies a maximum sowing depth of one sixteenth of an inch. Use a clear humidity dome or film until emergence, then vent it gradually. A cabinet manual estimates two to three days of germination under the dome. That is the only permitted cover, and it is transparent.

Do not weight it either. There is no blackout stack on this crop, so there is no weight, and pressing the seed for contact, which is standard advice everywhere else, is specifically contraindicated here. Mint is the first crop in this directory whose blackout is zero days rather than a short one.

Do not soak. The crop guide says no soaking, and the physical reason is obvious once you have handled the seed: it is dust, and wet dust cannot be spread evenly.

Water underneath, or very gently on top, and never with a coarse spray. Surface-sown seed at this size moves. A hard spray does not merely wet the tray, it rearranges the crop into piles and washes some of it under the surface, where the light requirement means it will not come up. This is the single most consequential handling difference between mint and everything else here.

Level the medium before you sow, more carefully than usual. A high spot dries and a low spot pools, and on a crop that takes ten days to show itself you will not learn which happened until it is far too late to fix.

Hold it at 68 to 75°F. That is the only crop-specific microgreen range published. Above about 79°F the same source says the aroma weakens, which on a crop grown entirely for aroma is the failure that matters. No validated lower limit exists for a mint tray, so cool rooms are an unknown rather than a known problem.

What goes wrong with mint specifically

Buried seed, and it is the failure that defines the crop. Covering the seed, or splashing it under with a spray, produces minimal germination. What you see is a tray that is bare in patches and clumped where the water ran. It is not repairable: you cannot add seed to a running tray and get an even stand, so the fix is to resow. On most crops here burying the seed slightly is forgivable. On this one it is the end of the tray.

"Is it dead or is it slow?" and there is no honest test. Ten to twelve days of nothing visible is reported as normal. Ten to twelve days of nothing visible is also exactly what a failed sowing looks like. Nobody publishes a day count at which a mint tray should be written off, and this page is not going to invent one. The one thing that resolves it is a labeled germination test on a damp paper towel from the same lot, run beside the tray, which tells you within a few days whether the seed can come up at all.

Mold at the surface, and mint stacks the odds against you. The crop guide flags excess moisture with poor ventilation as the mold risk, and mint arranges precisely those conditions: a humid dome, a surface you must keep damp because the seed is sitting on it, and a fortnight of it. The damping-off complex is the general one, Pythium and Rhizoctonia among the usual organisms, not a mint disease. Fine white growth that stays at the medium line and collapses when misted is root hair; growth climbing the stems, running gray or green, or smelling sour, is not. On a food crop that is a discard and a sanitize.

Dry shock when the dome comes off. Seedlings that have spent a week at dome humidity wilt and curl if you pull the cover in one go. Vent it in stages. This one is recoverable if the stems have not collapsed.

Weak aroma from heat or thin light. Pale, slow, faintly scented foliage. You can improve the tray's conditions from here, but the flavor of what you already cut does not come back, and flavor is the entire product.

Nutrition, and what is actually established

Nothing is established for this crop, and that is the finding rather than a gap.

There is no mint microgreen record in USDA FoodData Central. Searches for "mint microgreens", "spearmint microgreens" and Mentha spicata returned no microgreen entry, so there is no FDC ID and no nutrient panel to quote. Mature spearmint values are not a substitute for one.

No peer-reviewed composition study of spearmint microgreens turned up either. The nearest published work is a Lamiaceae microgreen paper that names mint as a commercially relevant member of the family and then measures basil-family material, not Mentha spicata microgreens.

So the claims you will meet, that mint microgreens have a specified vitamin and mineral profile, that they are more nutritious than mature mint, or that their menthol delivers a quantified health benefit, are unsupported for this crop at this stage. The specialist page that makes broad antioxidant and digestive statements supplies no analytical dataset behind them.

This directory has taken both sides of that question where the evidence supported it. Lettuce has real measurements showing the seedling beating its adult, and celery has real measurements going the other way. Mint has neither, and the honest answer is that nobody has looked. Grow it for the aroma, which is the thing you can actually verify by smelling it.

Which seed to buy

**Buy spearmint, Mentha spicata, named on the listing.** Peppermint is a different aroma and often a darker leaf, and "Chocolate" and "Black" are peppermint types rather than spearmint cultivars. No opened supplier publishes cultivar-specific stem length, days or yield for spearmint microgreens, so choose on species and on lot data, not on a variety name.

Ask for the four things that matter on a dust-fine, slow, expensive seed: the botanical name in writing, the crop year and lot, a germination percentage, and untreated food-use seed. The crop-specific source is explicit that pink or green dyed seed is not suitable for microgreens, and dye means a fungicide or insecticide coating. That seed is sold for a field, not for something you cut and eat in a fortnight.

There is no microgreen seed shelf for mint, and the search proves it. All 207 results for "mint microgreen seeds" were read: 101 are mint or Mentha sold as a garden herb, a tea plant, a ground cover or a live plant; 114 are microgreen or sprouting seed for other crops, mostly broccoli, radish, arugula and pea; the rest are kits, potting mix and noise. **Not one is Mentha sold for microgreens.** Both halves of the query are heavily stocked and the intersection is empty. That is a different failure from fennel, whose search also returns zero microgreen listings but is flooded with culinary spice seed of the same species. Here the flood is a garden-center flood.

So buy garden spearmint seed, and buy it by the seed count. This is the reverse of the usual advice on this site. Untreated heirloom spearmint packets are cheap and plentiful, run from a few hundred to twenty thousand seeds, and are the only practical route to a tray. Compare that with the seed-house ladder, which is where the crop's real cost lives.

Pennyroyal, and this is the one safety item on the page. Mint is sold in variety packs, and one on the same search is a four-way pack of spearmint, peppermint, lemon mint and pennyroyal. Pennyroyal is Mentha pulegium, and it is not a culinary mint. Its oil is roughly 85 percent pulegone, and the US National Institutes of Health's LiverTox database records pennyroyal oil taken by mouth as highly toxic, linked to cases of toxic liver injury and death, through metabolites that deplete the liver's glutathione. That evidence is about the concentrated oil, not about seedlings, and nobody has measured pulegone in a pennyroyal microgreen, so this page will not tell you what a tray of it would do. What it will tell you is the instruction: a mint variety pack is sold to be planted as four separate garden plants, one of which you would not eat. Do not sow a mixed mint pack as a tray you cut and eat whole, and read the species list before you buy one.

Is it worth growing?

For almost everybody, no, and unusually for this directory the reason is not the numbers. It is the competitor.

Every other crop here competes with a garden plant you have to sow every season. Mint competes with a spreading perennial that roots from a cutting in a glass of water, comes back every year whether you want it to or not, and can be cut repeatedly. Leek inverted this directory's garden-competitor pattern by being slower in the ground than in the tray. Mint inverts it the other way, harder than any crop here: the garden version is faster, free, effectively permanent, and its most-watched how-to is about stopping it.

Against that, the tray asks you to buy the most expensive seed in this directory, sow it in a way that contradicts every habit the other forty-two crops taught you, wait ten to eighteen days with nothing visible for most of it, and cut once, with no measured yield to plan against and no evidence that it regrows.

There is one real buyer. A restaurant or cocktail program that wants tiny, tender, uniform mint leaves, in winter, indoors, cut the same day, is buying something a pot on a windowsill does not supply: uniformity and a delivery date. Priced as a garnish, by the clamshell and never by the pound, that is a real product. Chives has the same shape of argument and better numbers behind it.

If you want mint for a kitchen, buy one plant. If you want a slow aromatic herb tray with published figures behind it, grow basil, which is the other Lamiaceae here and has three cultivars with measured yields. If you want volume, nothing on this page is for you.

A note on the numbers above

The seed rate is the number this page refuses to publish, and here is the arithmetic. A 1020 tray is 200 square inches, or 1,290 square centimeters. Fourteen grams of seed at Urban Farmer's own count of 10,999 seeds per gram is 153,986 seeds, which is about 119 seeds per square centimeter. For comparison, garden cress carries the only measured density study in this directory: peak biomass at 12 seeds per square centimeter, with total aerobic bacteria climbing steeply above that, and the study did not test past 14. A brassica tray runs two to four. So the one published mint rate is roughly ten times the highest density anyone has measured as optimal, and thirty to sixty times a brassica.

At two to four seeds per square centimeter a 1020 would want 2,600 to 5,200 mint seeds, which is a quarter to a half of one gram. That range is arithmetic on this crop's seed count, not a measured rate, and it is not going in the table either. It is here so a grower can weigh out a trial that is in the right order of magnitude instead of inheriting a figure that is off by a factor of forty.

The cost per tray follows the rate, which is why it is blank. The seed price is the best documented number on this crop and the rate is the worst, so multiplying them produces a precise-looking figure resting entirely on the weak half. At 14 grams the seed alone would be $43.04 at the pound rate and $151.20 at the gram rate, which would make mint the most expensive tray in this directory by four to fifteen times. At a quarter to half a gram it is $1.30 to $5.10, mid-pack. The two answers differ by a factor of thirty and nothing published settles which is right.

What is not in doubt is the seed price itself. At $1,394.50 a pound, spearmint is by a wide margin the most expensive seed per pound in this directory. Amended 2026-08-09, because the runners-up have moved twice since this was written: the next highest are now sorrel at $351.35, watercress at $296.25, oregano at $242.36, shiso at $155.50, onion at $113.30 and pak choi at $107.85, with basil Red Rubin at $93.40 and mustard at $88.30 below them. Mint is about 4 times sorrel rather than fifteen times anything. That is a fact about the plant's economics, not about the tray: mint is propagated from cuttings, so almost nobody harvests mint seed at scale, and a pound of it is a specialty item rather than a commodity.

Days to harvest is 10 to 18 because two sources disagree and neither states a stage, which is a weaker position than broccoli's 7 to 15, where the sources agree and simply measure different harvest points. Worse, the same guide that puts harvest at 14 to 18 days says the crop can be nearly invisible until day 10 to 12, and gives 20 to 30 days as a total cycle a few lines away. That internal contradiction is the most load-bearing uncertainty on this page, because it decides whether mint is a two-week crop or a month-long one, and therefore whether the bench time is worth anything at all.

The harvest window is blank, and mint is where this site's own prediction ran out of data. The lettuce entry proposed a mechanism for the four published harvest windows here: crops sold on taste sharpen as they sit and get one to three days, while lettuce has no flavor to sharpen and gets four to seven. It predicted that the remaining flavor crops, mint among them, would be narrow. Mint is the first of them to be researched and it cannot test the prediction, because nobody has measured how long a mint tray holds. As of 2026-08-09, 39 of the 43 entries written have no published window.

A blank means nobody has published that figure. Every crop here has a full research file; where no measured number exists this site leaves the cell empty rather than repeating an estimate. How the numbers work

All 61 crops, sortable, on the microgreen comparison.

Mint is the fourth crop here with no rate and no yield, after lettuce, cucumber and cauliflower, and it is the only one of the four where a rate exists and this site declined to use it. On lettuce, cucumber and cauliflower nobody published a number at all. On mint somebody did, and it does not survive contact with the other forty-two crops.

Sources

• UA Organic, mint microgreens - the only crop-specific mint microgreen guide opened: no soaking, no pressing, seeds need light and germinate minimally when covered, mold under excess moisture and poor ventilation, 68 to 75°F with aroma weakening above 79°F, 14 to 18 days and a 20 to 30 day cycle, nearly invisible through days 10 to 12, spearmint against peppermint on flavor and color, up to 7 refrigerated days cut, the advice against selling cut mint, dyed seed being unsuitable, and the culinary uses and clashes.
• Urban Farmer, Spearmint mint seed (Mentha spicata) - the price ladder verified 2026-08-09 at $3.00 per 250-seed packet, $10.80 a gram, $38.20 a quarter ounce, $117.40 an ounce, $394.00 a quarter pound and $1,394.50 a pound, plus the 10,999 seeds per gram that makes the density check possible.
• Sheffield's Seed Company, Mentha spicata - one real lot at 40 percent germination, 99 percent purity, 2023 crop year, and a maximum sowing depth of one sixteenth of an inch.
• Carter-Hoffmann GardenChef growing cabinet manual (PDF) - the 14 g per 10x20 estimate, 10 to 14 days to harvest and 2 to 3 germination days under a dome, with the manual's own statement that its figures are estimates that vary with variety, quality and conditions.
• Johnny's microgreens yield trial, method and discussion - mint is absent from the 29-variety trial, and the warning that one grower's yields do not transfer to another's system.
• UC IPM, damping-off - Pythium and Rhizoctonia as the damping-off complex under damp conditions, and symptoms at or below the medium line.
• NIH LiverTox, pennyroyal oil - pennyroyal as Mentha pulegium, the oil at roughly 85 percent pulegone, hepatotoxic and abortifacient constituents, cases of toxic liver injury and death from ingestion, and the glutathione-depleting metabolites.
• Kumar et al., Lamiaceae microgreens, Scientific Reports 2024 - names mint as a commercially relevant Lamiaceae microgreen and measures basil-family material rather than Mentha spicata.
• USDA FoodData Central - searched 2026-08-09 for mint microgreens, spearmint microgreens and Mentha spicata, no microgreen record.
• Iowa State Extension, germination requirements - the general 65 to 70°F post-germination seedling guidance, cited only to mark that it is not mint-specific.