Grow Spring Onions (Hara Pyaz) in Pots and in Water
Don’t throw away the white ends of your next bunch. The quickest answer to how to grow spring onions at home is this: stand those rooted ends in a little water, cut the new green after a week or two, then move them into a pot of soil where they keep giving for months. Spring onions (Hara Pyaz) also grow from seed and from small bulbs. Here are all three ways, with pot sizes, months and an honest word on full sized onions.
The short version
- Pot size: 5 to 8 litres, any width, at least 6 inches deep
- Sun: 4 to 6 hours; a bright windowsill works for regrown ends
- Sowing months (plains): September to November, and again in February
- First harvest: 1 to 2 weeks from scraps, 3 to 4 weeks from small bulbs, 8 to 10 weeks from seed
- Key rule: water is for starting; soil is for staying
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Which way should you start: scraps, small bulbs or seed?
Pick by how patient you are.
| Start from | First cut | Effort | Best for |
|---|---|---|---|
| White ends with roots | 1 to 2 weeks | Lowest | First timers, windowsills |
| Small onion bulbs (sets) | 3 to 4 weeks | Low | Thick, strong greens |
| Seed | 8 to 10 weeks | Medium | A full pot, cheaply |
Most homes do best with scraps for speed plus one pot of small bulbs for bulk. Seed is the cheapest route to a crowded pot, but onion seed loses its life quickly, so buy a fresh packet each season and don’t trust last year’s leftovers.
How to regrow spring onions from scraps in water
- Cut high. Leave 1 to 2 inches (3 to 5 cm) of white stem above the roots. A stub shorter than that has too little stored food.
- Stand them upright in a small glass, roots down, packed loosely so they hold each other up.
- Add very little water. Just enough to cover the roots, about half an inch. The white stem must stay dry or it turns slimy.
- Give it light. A bright kitchen window is enough. New green shows from the centre within 2 to 4 days.
- Change the water daily, or at least every second day, and rinse the glass.
- Cut at 5 to 6 inches. Snip with scissors, leaving an inch of green above the white.
The broader method for other vegetables is in our guide to regrowing vegetables from kitchen scraps; onions are simply the most reliable of the lot.
Why do onions in water get weaker after two or three cuts?
Because plain water has nothing in it to eat. The first flush of green is built almost entirely from food stored in that little white stub. The second flush is thinner. By the third the leaves are pale, narrow and mild, and the base often goes soft.
It isn’t your fault, and more sunlight won’t mend it. The plant has spent its savings.
The step most people skip: pot them after the first cut
Don’t wait for the ends to tire. Right after the first harvest, while the roots are white and an inch or two long, plant the ends in soil with the white part buried and the cut tip just showing. Fed by the soil, they regrow thicker than they ever did in the glass and can be cut again and again through the cool season, not just twice.
How to grow spring onions in pots, from small bulbs or seed
Use a pot at least 6 inches (15 cm) deep with drainage holes. A 5 to 8 litre tub, an old paint bucket with holes punched in the base, or a window box all work. Fill it with a loose mix; proportions are in our potting mix guide.
From small bulbs
- Choose bulbs about the size of a marble or a small lemon. The little onions left at the bottom of the basket, even ones already sprouting, are perfect.
- Press them in root end down, 2 inches apart, so the top third of each bulb sits above the soil.
- Water well once, then whenever the top inch is dry.
- Cut greens from 3 to 4 weeks, when they stand 8 inches tall.
From seed
- Sow thinly across the surface, aiming for a seed every half inch or so.
- Cover with about a quarter inch (half a cm) of fine mix and press gently.
- Keep it damp, never flooded. Thin, grass like loops appear in 7 to 12 days.
- Thin to 1 inch apart at 3 weeks and eat the thinnings.
- Start pulling or cutting at 8 to 10 weeks, when stems are pencil thick.
Sow a new pot every 3 to 4 weeks from September to November for a steady supply. Month by month timing for other crops is in the kitchen garden sowing calendar.
How to harvest so the pot keeps giving
You have two choices. Pull the whole plant, white and all, and the pot empties quickly. Or cut and come again: snip the green about an inch above the soil and leave the base to resprout. In soil, a healthy clump can be cut every 2 to 3 weeks through the cool months.
After each cut, water the pot and scratch in a spoonful of compost once a month. If a thick round stalk with a bud on top appears, the plant is flowering; cut that stalk off low, or let one bloom and enjoy the bees.
Did you know? Each hollow green leaf is a tube that grows from its base, not its tip. That’s why a cut leaf keeps lengthening from below, flat top and all.
As April heat builds in the plains the greens toughen and the bulbs go dormant. That’s the end of the season, not a failure. Hills and coast: in cooler hill towns you can sow from March right through summer, and in Karachi’s mild winter November to January is the reliable window.
Can you grow full sized onions in pots?
You can. It’s slow, and the sums are humbling. A bulb onion needs about 4 inches of space on every side, so a 12 inch, 15 litre pot holds five or six. Nursery seedlings go in during December or January in the plains and the bulbs are lifted in April or May, once the tops fall over on their own. That’s four to five months of balcony space for five or six onions.
Worth doing once, for the pleasure of it. For the kitchen, greens are the better use of a pot, and the sabzi wala remains your onion supplier.
A forgotten glass of water on a windowsill is a dengue mosquito nursery, so change the water every day or two and scrub the glass; if you can’t manage that, plant in soil from the start. Bin any onion end that turns slimy, grey or smelly; do not rinse and reuse it. Onions and their greens are harmful to cats and dogs, so keep jars and pots where pets can’t chew them. Wash greens under running water before eating, and never use insect spray on or near a pot you harvest from.
Spring onion growing questions, answered
How do you grow spring onions from scraps?
Keep the bottom 1 to 2 inches with the roots attached, stand them in half an inch of water on a bright sill, and change the water daily. New green is ready to cut in 1 to 2 weeks. Then move them to soil.
Can onions grow in water only?
For a short while. The green regrows two or three times on stored food, each flush weaker than the last. Without soil the base eventually softens and rots.
How long do spring onions take to grow?
About 8 to 10 weeks from seed, 3 to 4 weeks from small bulbs, and 1 to 2 weeks from regrown ends. Cool weather slows all three a little.
How do I regrow green onions in soil?
Bury the white ends about an inch deep, 2 inches apart, with the cut tips just showing. Water well, keep the pot in 4 to 6 hours of sun, and cut the greens an inch above soil whenever they reach 6 to 8 inches.
How do you grow onions in pots?
For greens, press small bulbs into a 6 inch deep pot and cut the leaves. For full bulbs, plant seedlings 4 inches apart in a large 15 litre pot in December or January and wait until the tops fall over in spring.
Which month is best for sowing spring onions?
September to November in the Pakistani and North Indian plains, with a second chance in February. They dislike the heat of May to August.
How many times can you regrow spring onions?
Two or three times in water. In a pot of soil with a little compost, the same ends can be cut many times across one cool season.
Do spring onions need full sun?
No. Four to six hours of direct sun gives the thickest greens, but they manage on a bright window, which is why they’re a good first plant for flats.
Why are my regrown onions slimy?
The water was too deep or left too long. Only the roots should sit in water, and it needs changing every day or two. Throw slimy ends away and start again with fresh ones.
Can I plant a sprouting onion from the kitchen?
Yes. Plant it with its top third above the soil and cut the green shoots as they grow. It won’t form a fresh big onion, but it gives weeks of greens.
Are spring onions and green onions the same thing?
In everyday kitchen use, yes. Both names mean onions picked young for their green leaves and slim white stem, sold here as hara pyaz.
If you liked this pot, garlic in pots is planted in the same months and gives its own greens. For more ways to use what the kitchen would bin, visit Zero-Waste Kitchen.