Spinach microgreens

Spinach is the only crop in this directory rated Difficult, and it earns it. It is also the only one where nobody has ever measured a 1020 tray: spinach is absent from the one public per-variety yield trial in the category, so unlike broccoli, kale, radish, mustard and cilantro, every seed rate and every yield figure you will read for it, including the ones at the top of this page, is an assertion or a conversion rather than a measurement.

It then compounds that by being one of the more expensive trays of seed here, at $2.52, sixth as of 2026-08-09 and the most expensive when this page was written, and returning very little crop per dollar: 2.9 ounces, which was the worst on the site when this page was written and has since been passed by chives at 1.7 and fennel at 0.42. Corrected 2026-08-08. This page is unusually blunt about all of that, because the alternative is selling somebody a difficult crop on optimism.

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

Spinach microgreens are seedlings of Spinacia oleracea, cut above the medium at the cotyledon or very early true-leaf stage. It is an Amaranthaceae crop, not a brassica, and that single fact explains most of what follows. Penn State describes the common brassica microgreens as 7 to 8 day crops; spinach runs two to three times that.

Two plants are sold under the word spinach and neither is this one. Water spinach is Ipomoea aquatica, a morning glory relative. New Zealand spinach is a different genus again. Both appear in microgreen content, both grow faster than real spinach, and neither is covered by anything on this page. Check the botanical name before you take a timeline from a guide.

A correct tray is narrow, strap-shaped mid-green cotyledons on slender, leggy pale-to-mid-green stems, and it is a thin, visibly gappy stand with medium showing between the shoots. That is the part worth internalizing. On every other crop here, visible medium means you underseeded or lost seedlings. On spinach it is normal, and a grower judging a spinach tray by broccoli's density will conclude they have failed when they have not.

It is confused with baby spinach rather than with any other microgreen, and the difference is developmental rather than visual: a microgreen is a cut shoot at cotyledon or just-emerging-true-leaf stage, while baby spinach comes later off established plants.

What it tastes like, and what to do with it

Mild, sweet and unmistakably spinach, with less of the bitterness the mature leaf carries, on tender leaves and juicy stems. It tastes like what it is, in a gentler register.

Use it where a mild green needs soft texture and a little leafy volume: folded into eggs, through a salad or a sandwich, scattered over pasta, or dropped onto a warm lentil soup at service. It is the wrong choice when the dish wants a peppery bite, which is mustard or radish territory, when it wants crunch, which is pea shoots, or when it needs a dense high-volume garnish, because the stand is sparse and will not deliver one.

The people who will not like it are the people who do not like spinach. Its young stage makes it milder and sweeter, not neutral, and nobody has run a consumer study on it. What also has not been established is which way the flavor moves if you cut late: the guides say flavor changes once true leaves begin, and none of them says it gets better or worse, so this page does not claim a direction.

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. Spinach departs from it in four ways and all four come from one root cause: the seed comes up slowly, unevenly, and prefers to be cool.

Sixty grams per 1020, and be clear that nobody measured it. This is one supplier's stated rate and there is no trial behind it. The controlled study used 60,000 seeds per square meter, roughly 7,740 seeds on a 1020's growing area, but never reported seed mass, so converting that to grams would be inventing a number. Penn State's instruction is the honest fallback: set density from the species, the seed weight, the tray area and your lot's actual germination percentage. On a crop this variable that is not bureaucracy, it is the only way to get an even stand.

Soak it or do not, but if you do, 8 to 12 hours in cool water. One guide says spinach can be sown dry and that soaking may speed germination; a supplier specifies 8 to 12 hours in cool water then drained, describing it as a softening and speeding treatment rather than a requirement. No controlled comparison exists and no water temperature is stated. Do not extend past 12 hours on the theory that more helps, because nothing here establishes either a benefit or a safety margin beyond it.

Surface-sow on level, fine, thoroughly moistened medium, and press firmly. Do not bury it. Firm seed-to-medium contact is specific leverage on this crop, because slow emergence gives every poorly-contacted seed more time to sit and do nothing. The seed is large and irregular, so even placement matters more than it does with dust-fine brassica seed.

Expect 4 to 7 days of weighted blackout, roughly double a brassica's. One protocol gives 4 to 5 days minimum and permits a few more for root development; another gives 5 to 7 in cool conditions. Use a small weight, 5 lb or less, for contact and an anchored even stand. Take it off when the majority have germinated and start lifting the cover, not on a date: waiting past that gives you weak, over-elongated stems, and this crop is leggy enough already.

Keep it cool, and stop treating the calendar as the answer. A supplier's ideal growing range is 61 to 68°F, the controlled study ran 75/64°F day and night, and Virginia Tech's general microgreen guidance is 60 to 70°F. None of those is a germination-temperature experiment, so this page records the germination range as unpublished rather than picking one. What is clear is the direction: cool suits it, and heat during a long wet blackout is the worst combination available.

Then give it light and stop watering so much. At least 6 hours a day in one protocol, 12 hours at 300 µmol in the study. Bottom water and drain the excess, because on a crop that sits wet and dark for the better part of a week, excess moisture is the failure.

What goes wrong with spinach specifically

Patchy, slow emergence, and it is the defining failure. Empty areas, or seed that has not even swollen while its neighbors are up. The causes are uneven moisture, poor seed-to-medium contact, or simply low-vigor seed. It is recoverable only if the lagging seed is clean and the tray is still early. The instinct to fix it with more water is exactly wrong and leads directly to the next failure.

Damping-off through the long wet blackout. Water-soaked or pinched stems, or seedlings that disappear before they emerge. Pythium often starts at the root tips and is favored by cool wet conditions, which is precisely the environment this crop asks for, and Rhizoctonia does the same job in warmer drier ones. A tray with active collapse is not a food crop: discard it, sanitize the trays, and fix drainage, spacing, temperature and irrigation before you sow again.

Stuck hulls and weak lift. Cotyledons trapped in the seed coat, or seedlings that cannot raise the cover. Spinach seed is large and irregular and it holds on, and a broadly helmeted tray is not commercially clean. Nobody has measured how often it happens, so budget cleanup rather than expecting a rate. This is why the spec above says "some" rather than "not applicable": on mustard the question genuinely does not apply, and on spinach it very much does.

Pale, stretched, over-aged shoots. A tray held dark after it is already lifting the cover, followed by rapid true-leaf development once it finally gets light. Move it promptly and cut at the intended stage; once it has outgrown the tray it is baby leaf, not the crop you meant to sell.

Root hairs against mold, judged on behavior rather than color. Root hairs form a uniform close fringe along individual roots at the medium surface. They do not bridge across stems, hulls or bare medium. Suspect mold when the fuzz spreads between plants, climbs stems or cotyledons, comes with collapse or a sour smell, or stays as a mat after watering. And if stems are pinched or water-soaked, stop diagnosing fuzz: that is damping-off.

A bad lot looks exactly like bad technique on this crop, more than on any other here, because slow uneven emergence is what spinach does when everything is right. The tell is low, delayed, non-uniform emergence from seed you spread evenly on a properly prepared tray. The remedy is evidence rather than intuition: read the supplied germination information, or run your own germination test, and recalculate the seeding weight for the viable percentage you actually have.

Nutrition, and what is actually established

USDA FoodData Central has no Foundation, SR Legacy, FNDDS or Experimental Foods entry for spinach microgreens. The only thing the search returns is a branded juice product, which is not a composition record for this crop. Mature spinach values are a different food at a different stage and are not a substitute.

What does exist is one good controlled study, and it is unusually detailed. Petropoulos and colleagues (2021) grew Palco F1 in peat and vermiculite at 60,000 seeds per square meter, harvesting stems and leaves at two fully expanded true leaves, 20 or 25 days after sowing depending on the nutrient treatment, under 24/18°C day and night with 12 hours of light. At 20 days of quarter-strength nutrient solution it measured 1.59 kg fresh weight per square meter, 156.4 mg total ascorbic acid per 100 g, 82.8 mg total chlorophyll per 100 g, 54.2 µg lutein per g, 44.0 µg beta-carotene per g, and 1,698 mg nitrate per kg fresh weight.

That nitrate figure is worth pausing on, because it is the kind of number that only appears when somebody actually measures rather than markets. It is a real characteristic of a leafy crop grown on nutrient solution and it is not something any supplier page mentions.

The claim that spinach microgreens are simply more nutritious than mature spinach is not supported as a blanket statement. This study shows composition moving substantially with cultivar, harvest stage and nutrient regime, which is an argument against any fixed multiplier rather than for one. And every figure above belongs to one cultivar under one set of conditions, so they describe that experiment rather than your tray.

Which seed to buy

The honest summary is that nobody has compared spinach cultivars as microgreens, so buy on availability and lot quality rather than on a name.

Palco F1 is the only cultivar with peer-reviewed microgreen data, and even that study did not compare it against anything else for stem length, color, tenderness or per-tray yield. Winter Giant, also sold as Giant Winter, is sold expressly as microgreen seed, described as heirloom, open-pollinated and cold resistant, and its page publishes nothing about microgreen days, stem length or yield. Bloomsdale, Matador, Oceanside and Lavewa appear as spinach seed options with no microgreen trait comparison at all.

So the meaningful specification is not the cultivar. Order untreated, uncoated seed sold for edible microgreen or sprout use, and insist on the lot number, germination percentage, test date, and seed count or weight. Penn State says suppliers should provide all of those, and on this crop you genuinely need them, because the seeding rate has to be calculated from real germinability rather than assumed. Refuse dyed, fungicide-treated or coated field seed: SDSU is explicit that treatment chemicals can end up in the young shoots, which are the entire product.

The cost of a bad lot here is higher than on any other crop in the directory, because a failed spinach tray occupies the bench for 16 to 25 days before you know. That is the real expense, not the seed.

Is it worth growing?

For most growers, no, and the numbers say so more clearly here than anywhere else on this site.

Spinach costs $2.52 of seed per tray, the most in this directory. It returns about 7 to 9 ounces, near the bottom. It takes 16 to 20 days on the supplier's own timeline, which is the second longest here. And it is the only crop rated Difficult, with mold risk rated High, because that long cool wet blackout is exactly what damping-off wants. Put those together and it returns roughly 2.9 ounces per dollar of seed, against broccoli's 14.5. It is the least economic crop in the directory by a factor of five.

It is worth growing when the flavor is specifically what somebody wants, and that is a real customer rather than a hypothetical one: mild sweet spinach in a tender form that mature spinach cannot give. If a chef asks for it, grow it and price it properly, which on these numbers means considerably above a brassica.

It is a poor first crop. A beginner expecting a reliable weekly turnaround will conclude they cannot grow microgreens, when what they actually chose was the hardest crop on the shelf. A market grower should trial a named lot with their own density and yield records before giving it rack space, because there is no benchmark to plan against. A home grower wanting dependable greens should grow almost anything else.

Its competition is any fast brassica, and the brassica wins on every axis except flavor. Do not treat them as equivalent because both are green cotyledon crops. Within its own family, bull's blood beet and swiss chard behave more like spinach than any brassica does, and a grower who wants that Amaranthaceae look with better odds should start there.

A note on the numbers above

This is the first crop where the correction is that there was nothing to correct against. On broccoli, kale, radish, mustard and cilantro, a controlled trial existed and the provisional figure was two to three times out. Spinach has no trial, and its provisional numbers turn out to be the closest of the seven: 40 to 60 g against the only published rate of 60, and 4 to 8 oz against figures landing at 7.2 and 7.1 to 8.8. The one place the old page was clearly wrong was in the other direction, at 21 to 35 days against a documented span of 7 to 25.

Three figures on this page are one publisher's house method, not spinach results. Added 2026-08-08, while researching endive. The 5 lb cover weight and the up-to-7-day shelf life above both come from a crop guide that also supplies endive's. Reading the two guides side by side, the crop-variable numbers differ sensibly, 7 to 10 days here against 8 to 15 there, at least 6 hours of light here against at least 12 there. The rest is the same sentence on both: five pounds or less against about five pounds, 10 to 15 minutes of bottom watering on both, a foot or two of light height on both, up to a week refrigerated on both, and no regrowth after harvest on both. That is a standard method with per-crop day counts dropped into it, which is a perfectly reasonable way to write a guide and is not evidence about spinach. The day counts carry the crop-specific information. The weight and the shelf life do not, and this page should not have implied otherwise.

Both yield figures on this page are inferences and neither is a measurement of a 1020. The lower one converts a peer-reviewed result reported per square meter onto a 1020's 0.129 m² growing area, which assumes the density transfers. The upper one is a supplier's claim. They agree at roughly 7 to 9 ounces, and that agreement is the only reason this field carries a number rather than a blank. Treat it as the best available estimate and weigh your own trays before pricing anything.

Days to harvest spans 7 to 25 because the sources are measuring different crops at different stages in different conditions. Seven to ten days is to fully opened cotyledons. Sixteen to twenty is a supplier growing deliberately cool. Twenty to twenty-five is a controlled study harvesting at two fully expanded true leaves, which is a materially larger plant. None of them is wrong, and averaging them would produce a number describing nothing.

Two fields are blank on purpose. Nobody measures how long a ready spinach tray holds its cut, and nobody has run a spinach germination-temperature experiment. A supplier's ideal growing range and a study's day-night regime are neither of them germination ranges, and this page will not convert one into the other.

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.

Spinach is last or second to last on both columns, and it is the only crop here that is also rated Difficult. Its row uses the supplier's own rate and its own 16 to 20 day timeline together, at 18 days, so the arithmetic is internally consistent rather than mixing sources. Broccoli returns five times the crop per dollar of seed and clears the bench in two thirds of the time.

That is the case against, stated plainly, and it is the sort of thing a directory can say when it has researched seven crops the same way. Prices move, so the dollar columns are dated; the rankings are the durable part.

Sources

• Petropoulos et al., 2021, spinach microgreens under differing nutrient regimes (PDF) - Palco F1 in peat and vermiculite at 60,000 seeds/m², harvested at two fully expanded true leaves 20 or 25 days after sowing, 24/18°C, 12 hours at 300 µmol, 65 to 75 percent RH, with 1.59 kg/m² fresh weight, 1,698 mg/kg nitrate, 156.4 mg/100 g total ascorbic acid, 82.8 mg/100 g chlorophyll, 54.2 µg/g lutein and 44.0 µg/g beta-carotene.
• True Leaf Market, Winter Giant spinach microgreens seeds - Spinacia oleracea sold expressly as microgreen seed, heirloom, open-pollinated and cold resistant, with no microgreen days, stem length or yield published, and the $19.09/lb price behind the cost calculation, listed 2026-08-08.
• Deliseeds, spinach microgreens seeds - the 60 g per 1020 rate, 16 to 20 days at an ideal 16 to 20°C, 7 to 10 days to sprout in cool conditions, an 8 to 12 hour cool-water soak, 5 to 7 blackout days, a 200 to 250 g yield claim, and the airflow instruction to prevent mold.
• Epic Gardening, spinach microgreens - 7 to 10 days to fully opened cotyledons, the cut window ending as true leaves grow, 4 to 5 blackout days with a weight of 5 lb or less, at least 6 hours of light, no regrowth after harvest, up to 7 days refrigerated in a sealed bag with a paper towel, retained seed casings, and the Bloomsdale, Matador, Oceanside and Lavewa options.
• Johnny's microgreens yield trial results (PDF) - 29 varieties, and no spinach row. The absence is why no measured seed rate or yield exists for this crop.
• Johnny's microgreens yield trial, method and discussion - 1020 flats, seed weighed by packet difference, first-true-leaf harvest, and the warning that one system's yields do not translate to another's.
• Penn State Extension, The ABCs of Microgreens (PDF) - the 7 to 8 day maximum for common brassicas that sets spinach's slowness in context, seeding density as a function of species, seed weight, tray area and lot germinability, and the lot number, germination percentage, test date and seed count a supplier should provide.
• Penn State Extension, a step-by-step guide for growing microgreens at home - the default method spinach departs from, bottom watering, and washing immediately before use because washing substantially reduces shelf life.
• Virginia Tech Extension SPES-756 (PDF) - the general 60 to 70°F production range, uncovering once most seedlings have germinated, and damping-off and mildews as the principal indoor disease concerns.
• SDSU Extension, growing microgreens at home - why dyed, fungicide-treated or coated seed is unacceptable on a crop eaten as young shoots.
• UC IPM, damping-off - Pythium favored by cool wet conditions and often starting at root tips, Rhizoctonia in warmer drier ones, and rot at or below the medium line.
• USDA FoodData Central, spinach microgreens search - searched 2026-08-08: no Foundation, SR Legacy, FNDDS or Experimental Foods record, only an unrelated branded juice product.