Onion Seeds (Pyaz ke Beej) Are Not Kalonji: How to Tell
Pyaz ke beej (true onion seeds) are the seeds you sow to grow onions, not the black spice on your naan. That spice is kalonji (nigella), which English packets often mislabel as “onion seed” or “black onion seed”. Here’s how to tell the two apart in ten seconds, why seed-shop onion seeds should never go in food, and how to grow spring onions from them on a balcony.
Quick facts
- Kalonji: Nigella sativa, a buttercup-family plant. The spice.
- True onion seed: Allium cepa. For sowing, not cooking.
- The sniff test: crushed kalonji smells peppery and a little like oregano; crushed onion seed smells of almost nothing.
- Seed-shop warning: packets for sowing may be coated with fungicide. Never eat them.
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Are onion seeds and kalonji the same thing?
No. They come from different plants that aren’t even close relatives.
Kalonji grows on a small plant with pale blue flowers and puffy seed pods. The seeds are the familiar black spice in achaar, naan and nimko. Onion seeds come from the round white flower balls of an onion plant that’s been left in the ground to bloom.
The mix-up is mostly a labelling habit. Somewhere along the line, English-language shops started calling kalonji “onion seed”, possibly because the two look similar and kalonji goes so well with onion dishes. Recipe sites copied it. So a UK or US recipe asking for “onion seeds” almost always means kalonji.
How do you tell onion seeds from kalonji?
Put a few of each on a white plate in good light.
| Check | Kalonji | True onion seed |
|---|---|---|
| Shape | Small, sharply angled, like a tiny wedge with 3 or 4 faces | Larger, rounded on one side, flattish on another, like a crumpled half-moon |
| Surface | Matte black, finely wrinkled and rough | Black, with a more irregular wrinkled skin |
| Crushed smell | Peppery, slightly oregano-like, a little bitter | Faint, nutty, barely any smell |
| Inside | White, oily | Pale, starchy |
The smell test is the clearest. Crush a seed between two spoons. If your kitchen suddenly smells like a naan shop, it’s kalonji.
A packet that’s pink, green, blue or dusty-coloured is a coated seed for sowing. That colour is the fungicide treatment, and it’s another reason to keep seed-shop packets well away from the spice shelf.
Can you eat true onion seeds?
Untreated onion seeds aren’t poisonous, and in a few places sprouted onion seeds are eaten as microgreens. But they aren’t a spice. They taste bland and woody, and they don’t give the flavour a recipe wants.
The real problem is where you’d buy them. Onion seed is sold for farming and gardening. Many packets are treated with fungicides or insecticides so the seed doesn’t rot in damp soil. Those chemicals are fine in a field and not fine in your daal.
- Never cook with seed from a nursery, seed shop or garden centre packet.
- Keep sowing seed in a labelled tin, apart from kitchen spices, and out of children’s reach.
- If a child eats a coated seed packet, call a doctor or poison help line and keep the packet to show them.
What people say about onion seeds, and the honest answer
What people say
Online, “onion seed benefits” lists promise hair growth, lower sugar and weight loss. Almost every one of those lists is really describing kalonji, using the wrong English name.
What tradition says
Kalonji, called habbat-ul-sauda in Arabic and Tibb-e-Nabvi, has a long and respected place in Unani and Islamic medicine traditions, and in desi kitchens. True onion seeds have no such tradition as food; farmers’ families kept them only to sow next season’s crop.
Our honest take Skip as a food
If a health claim mentions “onion seeds”, check whether the photo shows kalonji. For the spice and its fair account, read our kalonji guide. True onion seeds belong in soil.
How do you grow spring onions from seed?
This is where true onion seeds earn their keep. Spring onions (hari pyaz) are the easiest kind to grow, and you harvest the green tops before any bulb forms.
- Fill a pot or tray at least 15 cm deep with loose, well-drained soil mixed with compost. A 30 cm pot holds a good bunch.
- Sow seeds about 1 cm deep and 2 to 3 cm apart. Cover lightly and press the soil down.
- Water gently so the seeds don’t wash out. Keep the soil damp, not soggy.
- Keep the pot where it gets at least 5 to 6 hours of sun. Seeds usually sprout in 7 to 14 days in mild weather (roughly 15 to 25 °C).
- Thin crowded seedlings to about 2 cm apart. The thinnings are edible.
- Harvest from about 8 weeks, when the stems are pencil thick. Cut the greens 3 cm above soil and they’ll regrow once or twice.
In most of Pakistan and North India, autumn (roughly October to November) is the classic sowing time for the plains, with the cool months for growing. Hot summer and heavy monsoon rain both make seedlings struggle.
Why old seed fails
Onion seed loses its ability to sprout quickly, often within a year or two. Buy fresh seed each season, check the packing date, and store the rest in an airtight jar in a cool, dry place.
Myths about onion seeds
Myth: “Black onion seed” is just a seed from the onion you cook
“Black onion seed” on a spice packet is kalonji. The seeds of the onion plant are a different seed and aren’t sold as a spice.
Myth: Onion seed oil is the same as kalonji oil
Products labelled “onion seed oil” for hair are frequently kalonji oil. Read the botanical name: Nigella sativa is kalonji.
Did you know?
An onion only flowers in its second year. In the first season it stores food in the bulb; left in the ground, it sends up a tall hollow stalk topped with a ball of hundreds of small white flowers, each of which can set black seeds. And if you’ve kept onions too long, the green shoot is the same urge starting early; see our page on stopping onions from sprouting.
Don’t eat or cook with seeds bought for sowing, even if they look like kalonji. Treated seed can carry farm chemicals. Store gardening seeds labelled and out of children’s reach, and wash your hands after handling coated seed. If you’re buying the spice, buy food-grade kalonji from a grocery or spice shop, in a sealed food packet.
Onion seeds and kalonji: your questions
Are onion seeds and kalonji the same?
No. Kalonji is Nigella sativa, a spice. True onion seeds are from the onion plant and are for sowing. English labels often call kalonji “onion seeds”, which causes the confusion.
What is the English name of kalonji?
Nigella or black cumin is the most accurate. “Black seed” is common too. “Onion seed” and “black onion seed” are widespread but botanically wrong.
Pyaz ke beej kahan se milte hain?
True onion seeds are sold at seed shops, nurseries and agricultural stores for sowing. The black “onion seeds” in grocery spice aisles are almost always kalonji.
Can I eat onion seeds bought from a nursery?
No. Seed for sowing is often treated with fungicide or insecticide. Keep it for the garden only.
How do I know if my packet is kalonji or onion seed?
Crush a seed. A peppery, slightly oregano smell means kalonji. Barely any smell, a rounded half-moon shape, or a coloured coating means onion seed for sowing.
How long do onion seeds take to grow?
They usually sprout in 7 to 14 days in mild weather. Spring onion greens are ready from about 8 weeks; full bulbs take 4 to 5 months.
Are onion seeds good for hair?
Most “onion seed for hair” products are kalonji oil or onion juice. Neither is a proven hair-loss fix; persistent hair fall is worth checking with a doctor.
Can I grow onions from kalonji seeds?
No. Kalonji grows into a nigella plant with blue flowers, not onions.
When should I sow onion seeds in Pakistan?
In the plains, roughly October to November is the main sowing window, growing through the cool months. Avoid peak summer heat and monsoon downpours.
More kitchen myths, sorted honestly, are in Desi Remedies.