How to Grow Nasturtium: Sow Now, Skip the Fertiliser, Get Flowers
If you want to know how to grow nasturtium and get flowers instead of a pot full of round green leaves, the whole secret is neglect: sow the big seeds straight into a sunny pot of plain, unfed soil between October and early December, water only when the top inch is dry, and never give it fertiliser. Starved nasturtiums bloom. Pampered ones sulk.
Nasturtium in one look
- Sow in the plains: mid October to early December (Lahore, Delhi, Faisalabad, Multan); November to January in Karachi
- Hills: sow March to May after frost, it flowers through summer
- Pot: 8 to 10 litres (10 inch) for one bushy plant, a 12 inch hanging basket for trailing types
- Sun: 5 to 6 hours; afternoon shade once March turns hot
- First flowers: usually around 7 to 9 weeks after sowing
- Feed: none. Really.
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Why does a poor soil give more nasturtium flowers?
Nasturtium (Tropaeolum majus, sometimes sold as Indian cress) is one of the few garden plants that reads rich soil as a reason to make leaves. NC State’s extension plant database says it plainly: lean to moderately fertile, well drained soil, and extra fertiliser gives more foliage and fewer flowers. So the bag of vermicompost that makes your tomatoes happy is the wrong friend here.
That makes it the cheapest flower on the roof. Ordinary garden soil, a handful of sand, and a pot with a working drainage hole. Done.
Seed or nursery seedlings: which is better for a beginner?
Seed, without much argument. Nasturtium seeds are the size of a chickpea, easy to handle, and they grow fast. The plant also dislikes having its roots disturbed, so a nursery seedling crammed in a small polythene bag often stalls for two weeks after you move it. Buy a seedling only if you missed the sowing window and it’s already late December. Even then, pick one that is small and not yet flowering.
How do I grow nasturtium from seed, step by step?
- Soak: put seeds in room temperature water overnight, about 8 to 12 hours. The hard coat softens and they sprout sooner.
- Mix: 2 parts garden soil, 1 part coarse sand or brick grit, and at most a small handful of compost for a 10 inch pot. No manure.
- Sow: push 2 or 3 seeds about 2 cm (one finger joint) deep, spaced around the pot.
- Water once thoroughly, then keep the mix just damp, not wet. Seedlings usually appear in 7 to 14 days.
- Thin: when each has 4 true leaves, keep the strongest one or two per 10 inch pot. Snip the others at soil level; their leaves go into a salad.
- Place: full winter sun on the roof or balcony rail. Trailing kinds spill nicely from railings and hanging baskets.
Want to raise trays of many flowers at once? Our seed starting guide covers trays and hardening off, though nasturtium really is happier sown where it will live.
When do nasturtiums flower in Pakistan and North India?
| Zone | Sow | Flowers |
|---|---|---|
| Karachi, coastal humid | November to January | January to April |
| Lahore, Faisalabad, Delhi | Mid October to November | Late December (slow in fog) to April |
| Multan, Sukkur, Bahawalpur | Late October to November | January to March, fades by April heat |
| Islamabad, Peshawar | October, or February for spring | March to May |
| Murree, Swat, hills | March to May | June to September |
On the plains it is a cool season annual. Once nights stay warm and days touch 38°C, the plant yellows and collapses. You will not keep it through a 45°C June, so don’t try.
How much water does a potted nasturtium need?
Winter: every 3 to 5 days in a clay pot, less in plastic, when the top 2 to 3 cm feels dry. On foggy weeks in Lahore you may go a week. In Karachi’s mild winter, every 2 to 3 days. Frost nights in the Punjab can scorch the soft leaves, so pull pots under a roof overhang when the forecast drops near 2°C. By March, water every other day and move the pot where it gets morning sun only. For a fuller picture of seasonal watering, our watering guide for potted plants breaks it down by pot type.
The aphid decoy trick
Black aphids love nasturtium more than they love your broad beans or mustard. Gardeners put one pot near the vegetable bed as a sacrificial trap. When the undersides of the leaves turn black with aphids, snip those stems, drop them in a bag of soapy water and bin it. You’ve taken the colony out in one go without spraying anything on food plants.
Why is my nasturtium not flowering?
- Too much food: fertiliser, rich compost, or manure in the mix. Stop feeding and wait; the next flush is usually flowers.
- Too little sun: under 4 hours makes long stems and few buds.
- Sown too late: a January sowing in Multan barely gets going before the heat.
- Pot too big and too wet: soggy soil keeps it in leaf mode and can rot the stem base.
Pests and problems, and what to do first
Aphids and whitefly are the regulars, with occasional caterpillars that chew holes in leaves. Start with a strong jet of water under the leaves, then hand picking. If you do use an insecticidal soap or neem product, read the label, spray in the evening, keep children away until it dries, and remember that the leaves are eaten, so respect any waiting time the label sets. Yellow, wilting plants in warm wet soil usually mean root rot or wilt: pull them, don’t compost them.
Can I eat nasturtium leaves and flowers?
Yes. Leaves, flowers and young green seed pods are edible and taste peppery, a bit like watercress or mooli leaves. Chop a few into raita, scatter petals on a salad, or pickle young green pods in vinegar. Eat flowers you grew without sprays; nursery plants may have been treated with chemicals not meant for food. Keep portions to garnish amounts.
Only eat plants you grew and are sure are nasturtium. NC State flags it as a problem plant for cats, dogs and horses, so keep pets from chewing it. If anyone gets a rash or mouth irritation, stop and wash. If a child or pet swallows a chemical spray, call a doctor or vet straight away with the label in hand.
How do I save nasturtium seed for next October?
Leave a few faded flowers on the plant. Each makes a cluster of three ridged seeds that start green and turn pale brown. Let them dry on the vine until they drop or come away with a light touch, usually March or April. Dry them indoors for another two weeks on a plate, then store in a paper envelope in a cool dark cupboard. Seed from mixed colours may not match the parent, which is part of the fun.
Grow it or skip it?
Grow it if you want a beginner’s flower that costs almost nothing, fills a railing pot fast and gives a peppery garnish. Skip it if you only have a shady veranda, or if you want summer colour: on the plains this is strictly an October to April plant. In pots rather than ground for most homes; in the ground it can self seed and wander. Pair it with sweet alyssum along a vegetable bed for a cheap, useful border. More winter flowers live in our Phool aur Paudhe section.
Nasturtium questions people search
How do I grow nasturtium from seed?
Soak the seeds overnight, sow them 2 cm deep in lean, well drained soil in a sunny pot, and keep the soil just damp. They sprout in one to two weeks and need no feeding at all.
When should I sow nasturtium seeds in Pakistan?
Mid October to early December on the Punjab and Sindh plains, November to January in Karachi, and March to May in the hills after the last frost.
How long does nasturtium take to flower?
Usually around seven to nine weeks from sowing in good winter sun. Fog and short days in Lahore or Delhi can push the first flowers to late December or January.
Why is my nasturtium all leaves and no flowers?
Almost always too much fertiliser or rich compost. Stop feeding, give it at least five hours of sun, and let the soil dry a little between waterings.
Is nasturtium an annual or a perennial?
It is grown as an annual. On the plains it lives from autumn to the first real heat in April, then dies, and you sow again in October.
Can nasturtium grow in a hanging basket?
Yes, trailing types suit a 12 inch basket well. Baskets dry fast, so check them daily from February onward.
Should I deadhead nasturtiums?
Pinching off faded flowers keeps new buds coming. Stop deadheading a few weeks before the heat if you want to save seed.
Do nasturtiums really keep aphids off vegetables?
They act as a decoy, attracting aphids to themselves rather than repelling them. You then remove the infested stems, which reduces the number reaching nearby crops.
Can nasturtium survive summer in Lahore?
No. Above roughly 38°C it yellows and dies back. Treat it as a winter flower and save seed for next season.