Sorrel microgreens

Sorrel has the second most expensive seed in this directory, $351.35 a pound, behind only mint.

It also makes one of the cheaper trays here: $2.71.

Both are true because sorrel uses 3.5 grams a tray, the lightest weighed rate on this site. Oregano's page put the general version of this plainly: the price on the bag has never once predicted the cost of the tray in this directory. Sorrel is the cleanest single proof of it, because for once both halves of the sum are measured.

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

Read the botanical name on the packet before anything else. The chef-facing crop is Rumex sanguineus, red-veined sorrel, and every microgreen supplier opened here sells that species. **Common sorrel, Rumex acetosa, is a different plant** also sold as "sorrel". The trade names pile up further: bloody dock, red-veined dock, wood dock, spinach dock, narrow-leaved dock. They are all names for the red-veined species, but "sorrel" alone on a label promises nothing.

It is in the Polygonaceae, the buckwheat family, which makes it the second of that family here after buckwheat and nothing like it in the tray.

The product is the leaf, not the stem. A correct tray is small, bright green leaves crossed by conspicuous red to purple veins, on fine crimson stems. Do not expect a red leaf: green blade with red venation is the crop. That veining is also the identification tell, because plain green sorrel and green dock look the same at a glance and lack it.

Johnny's trial cut at first true leaf, at 24 days. Its 3.5 g rate is stated for "very small leaves", and the same page tells you to sow less if you intend to grow them bigger, which is the opposite of the instinct.

What it tastes like, and what to do with it

Bright, sharp, lemon-tangy. This is an acid rather than a flavor: sorrel does on a plate what a squeeze of lemon does, and it is strong enough to be used by the leaf.

That makes it a seafood garnish, a canape topper, a composed-salad accent, a dessert garnish (its supplier names that use specifically), and a contrast element in an otherwise mild blend. It is the wrong crop for bulk, crunch or a neutral base.

Anyone who dislikes sour will dislike it, and that is not a matter of getting the growing right.

There is a second reason not to eat it by the handful, and it gets its own section below.

Oxalic acid, and why this page will not give you a number

Sorrel is sour because of oxalic acid, and the extension sources that describe the species are explicit about it: Wisconsin Extension says the plant contains oxalic acid and should not be eaten in large quantities, and N.C. Extension notes possible stomach upset and that large intake can bind nutrients.

Those are statements about the plant, not measurements of a microgreen serving, and this page will not convert one into the other.

Here is the pointed part. A 2020 peer-reviewed study did measure oxalate in microgreens, alongside protein, fiber, minerals, ascorbic acid, alpha-tocopherol and beta-carotene, across ten culinary crops: spinach, carrot, mustard, radish, roselle, onion, fenugreek, sunflower, French basil and fennel. Sorrel is not one of the ten. The one study that measured the thing sorrel is defined by skipped the crop where it matters most.

So the honest position is a direction without a dose. Sorrel is a high-oxalate plant used as a garnish in small amounts, which is how the trade sells it and how the flavor pushes you to use it anyway. Anyone told to limit oxalate should treat it as a high-oxalate food and not as "a microgreen, therefore a vegetable serving". Nobody has published the milligrams.

Growing it: only what differs from the standard method

Four departures, and three of them are things you do not do.

No soak. The published sorrel guide lists pre-soak: no. No source gives a duration or temperature, so there is no short-versus-long soak question to answer.

No blackout, and no weight. The guide lists blackout "Nil", and grower reports independently converge on a humidity dome and nothing on top. This is a different thing from what lettuce, mint and purslane do, and the difference is worth keeping straight: those three must not be blacked out because their seed is light-responsive and darkness suppresses germination. Nothing says sorrel's seed needs light. It simply is not a blackout crop in any protocol anyone has published.

Sow 3 to 3.5 grams and no more. At about 1,150 seeds a gram that is still roughly four thousand seeds in the tray, so a rate that looks absurdly sparse on the scale is not sparse in the medium. Broadcast, press for contact, cover lightly or dome, and bottom-water so the medium does not splash onto very small plants.

Then wait longer than feels right. Germination alone is published at five to ten days, and harvest at 24 to 30. The single most reported mistake on this crop is deciding at day four that the tray has failed.

What goes wrong with sorrel specifically

Almost everything that goes wrong is a reaction to the slowness.

Mistaking the germination window for failure. Five to ten days is normal here. Growers re-sow, add water, add a weight, or add a blackout, and each of those makes it worse. Recoverable until the ten-day window is genuinely past and the seed has clearly decayed.

Damping-off around emergence, on general pathology rather than a sorrel study: seedlings rot at or below the medium line, or never appear. Pythium typically starts at root tips and is favored by cool wet conditions; Rhizoctonia can appear warmer and drier. Individual seedlings do not recover. The tray sometimes does, if losses are limited and you fix moisture and airflow.

The usable field test, again general rather than sorrel-specific: white fuzz confined to otherwise healthy root tips at the medium is root hairs, and is not a reason to bin a tray. Spreading growth, decay, or seedlings collapsing at the soil line is disease.

Late-crop pests on a long tray. One grower report describes yellowish aphids and a white leaf coating, and the species is listed outdoors with slugs, rust and powdery mildew. A three-to-four week tray simply gives pests more time than a nine-day brassica does. This is observation, not a crop-specific indoor diagnosis.

Cutting late. Leaves get larger and coarser and the delicate red-veined garnish stops being one. The mature plant goes tough and bitter with age, which supports the direction, and nobody has published the day it happens in a tray.

Nutrition: nothing, and an unusually specific nothing

USDA FoodData Central returned no entry for red-veined sorrel microgreens, searched across all data types on 8 August 2026. No FDC ID, no nutrient values.

**No peer-reviewed nutrient-composition paper for Rumex sanguineus microgreens was found either.** The supplier claim that this crop supplies vitamins A, B complex, D and E plus a long mineral list appears on a product page with no analysis behind it, and it should not be turned into numeric nutrition copy.

What makes this absence sharper than most on this site is the oxalate study above: the composition work on culinary microgreens exists, it measures exactly the compound this crop is known for, and it does not include this crop.

Which seed to buy

One market type: **Red Veined sorrel, Rumex sanguineus**. Johnny's version is organic and open-pollinated at 26 to 30 days; Hoss sells it untreated at 17 to 28 days. No supplier page establishes named cultivars that differ reliably in stem length, tenderness, yield or color.

Specify the botanical name, untreated status, and lot and germination information for production quantities. Refuse seed treated for ornamental or field use, since the harvest is eaten raw.

Pack size matters more here than on most crops. Johnny's listed the pound at $351.35 and a single ounce at $35.40, which is $566.40 a pound. On the 3.5 g rate that is the difference between $2.71 and $4.37 a tray for the same seed. On a crop this slow, buying the small pack twice is the expensive habit.

On price it runs about 1.5 times the seed house, the same shape as shiso: Mountain Valley's 1 oz at $32.28 is $516.48 a pound and $3.99 a tray, and Hoss's 8 g "Red Panda" at $9.99 is $566.50 a pound and $4.37 a tray, against Johnny's $2.71. That Red Panda is a named cultivar no source opened here describes, so this page says nothing about how it grows.

One inconsistency to know about before you calculate anything. Mountain Valley states about 15,000 seeds an ounce, which is roughly 529 a gram. The published growing guide says about 1,150 a gram. Those are a factor of two apart, from two suppliers of the same crop, so weigh your seed rather than counting it.

And test the lot before committing a tray slot. A bad lot on a nine-day brassica costs you nine days. Here it costs three to four weeks, and you will not be sure it was the seed until most of that has gone.

Is it worth growing?

Grow it if you are selling a premium visual garnish and can charge for acid and color in small portions. That is a real market and this crop serves it well.

Do not grow it for weight or for speed. Johnny's own trial makes the trade-off concrete in one line: red-veined sorrel at 24 days and 6.5 oz against broccoli at 12.5 days and 11.5 oz from the same 1020, both cut at first true leaf. That is roughly twice the time for a bit over half the weight.

For a one-tray home grower it is justified only if you actually want lemon-tart red-veined leaves. If you want forgiving daily salad, this is the wrong end of the directory.

A note on the numbers above

The seed is the second most expensive per pound here and the tray is not, and that pair is the whole economic point. At $351.35 a pound sorrel sits behind only mint's $1,394.50 and ahead of watercress's $296.25, oregano's $242.36 and shiso's $155.50. At 3.5 g it makes a $2.71 tray, which is ordinary. 3.5 grams is the lightest weighed rate in this directory, and the only lighter figure on the table, celery's 1.1 to 4.4 g, was calculated rather than weighed because celery is absent from the trial.

What it returns for that is thin. 6.5 oz over 24 days is 2.40 oz per dollar of seed and 0.27 oz per tray-day. Both sit in the bottom third. Sorrel is not sold by the ounce and its economics only work if the price per gram to the buyer is a garnish price.

On the harvest window, sorrel is the fifth crop to have the mechanism and not the measurement. Lettuce predicted that crops sold on flavor get short windows, and named mizuna, mint, oregano, shiso, sorrel and thyme. Sorrel has the mechanism in the clearest form yet: the species is documented as lemony-tart young and tough and bitter old, and the tray product is explicitly the "very small leaves" stage. Nobody has measured how many days that stage lasts. Five of the six named crops are now researched and not one has published a window. Thyme is the last one, still unwritten as of 2026-08-09, and the likeliest conclusion is already visible: hold time gets measured on crops sold by weight, and nobody measures it on herbs sold by the leaf.

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.

Sources

• Red Veined sorrel organic microgreen seed, Johnny's - the 3.5 g rate, 26 to 30 days, the bright lemon description, the temperature guidance, and the $351.35 per pound and $35.40 per ounce prices listed 8 August 2026.
• Johnny's microgreen yield trial summary and the trial tech sheet - 3.5 g, 6.5 oz and 24 days to first true leaf, the broccoli comparison, and the trial's caveat that yields do not transfer perfectly between systems.
• Red veined sorrel microgreens, Hoss - 17 to 28 days, 5 to 10 days germination, untreated seed, and the unsupported nutrient claim this page declines to repeat.
• Sorrel red veined microgreens seeds, True Leaf Market - the spinach dock and narrow-leaved dock trade names.
• Microgreen growing guide, Seedmart Australia - 3 g per 10x20, no pre-soak, nil blackout, 180 g at up to 30 days, and about 1,150 seeds a gram.
• Rumex sanguineus, N.C. Extension - species identity and the note on stomach upset and nutrient binding with large intake.
• Bloody dock, Wisconsin Extension - the oxalic acid caution, the lemony-tart-young to tough-and-bitter-old direction, and the outdoor pest list.
• Ghoora, Babu and Srividya, 2020, "Nutrient composition, oxalate content and nutritional ranking of ten culinary microgreens", Journal of Food Composition and Analysis, DOI 10.1016/j.jfca.2020.103495 - measured oxalate in ten crops, none of which is sorrel.
• USDA FoodData Central - searched 8 August 2026, no record.
• Damping-off, UC IPM - the pathology and the root-hairs-versus-disease test.
• Microgreens production, Virginia Cooperative Extension and Growing microgreens at home, SDSU Extension - general controlled-environment risks and general storage guidance, neither used as a sorrel figure.
• Grower reports on r/microgreens describing growing issues and the no-weight approach and germination trouble.