How to Grow Nasturtiums
Tropaeolum majus
Peppery, edible flowers and leaves that thrive on neglect and smother weeds.
By the Plants by Zone Editorial Team · Reviewed June 1, 2026
About nasturtiums
Nasturtiums are one of the most carefree flowers you can grow — they actually perform best when neglected, since rich soil pushes lush leafy growth at the expense of blooms. Every part is edible: the peppery flowers brighten salads, the rounded leaves add a watercress-like bite, and the unripe green seeds can be pickled just like capers. Bushy types mound at 12 inches, while trailing and climbing varieties tumble over walls or clamber up a trellis.
When to plant and harvest nasturtiums
Timing is relative to your frost dates. Find your USDA zone for exact dates, or browse the month-by-month calendars.
Start seeds indoors
2–3 weeks before last frost (optional — direct sow is preferred)
Transplant outdoors
After last frost; handle roots gently, they dislike disturbance
Direct sow
1–2 weeks after last frost in warm soil; 2–3 weeks before last frost in cool climates
Harvest
Summer until frost
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How to grow nasturtiums step by step
- 1
Direct-sow ½ in deep in average to poor soil after the last frost — nasturtiums hate root disturbance and resent transplanting.
- 2
Withhold fertilizer entirely; lean, well-drained soil produces more blooms, while rich soil gives leaves.
- 3
Water only to establish; once growing they tolerate drought well and need little attention.
- 4
For climbing and trailing types, loosely guide the first long stems toward a trellis or fence.
- 5
Pick flowers and leaves regularly — harvesting encourages more bloom and keeps the plant tidy.
- 6
Let a few seeds develop at season's end; nasturtiums self-sow freely and will naturalize over time.
Common problems growing nasturtiums
⚠ Black aphid colonies on the stems
Nasturtiums famously attract aphids and work well as a sacrificial trap crop near vegetables. Blast infested stems hard with water, or simply let natural predators arrive; cut the worst stems to the ground and discard.
⚠ All leaves, few flowers
Overly rich soil or shade — move them to lean, well-drained ground in full sun and skip fertilizer entirely.
⚠ Mildew or foliage collapse in heat
Nasturtiums prefer cool weather and can flag mid-season in hot climates; shear the plant back by half and it will flush fresh growth once temperatures ease.
✗ Keep away from
🧺 Harvesting nasturtiums
Pick nasturtium flowers in the morning once fully open, choosing vivid, unmarked blooms — they make striking salad garnishes and can be stuffed with soft cheese. Harvest leaves while young for the mildest peppery flavor. Collect unripe (still green, marble-sized) seeds and pickle them in brine and vinegar as a caper substitute; dried mature seeds are spicy but can be cracked into pestos and dressings.
Nasturtiums: frequently asked questions
When should you plant nasturtiums?＋
In most regions you start seeds indoors 2–3 weeks before last frost (optional — direct sow is preferred), then transplant after last frost; handle roots gently, they dislike disturbance — or direct sow 1–2 weeks after last frost in warm soil; 2–3 weeks before last frost in cool climates. Timing is relative to your last frost, so find your USDA hardiness zone for the exact planting dates where you live.
Are nasturtium flowers really edible?＋
Yes — flowers, leaves, and unripe seeds are all edible, with a peppery, watercress-like flavor. The species to eat is Tropaeolum majus; confirm the species before consuming any "nasturtium."
Why does my nasturtium have tons of leaves but no flowers?＋
Almost always too much nitrogen from rich soil or fertilizer, which drives vegetative growth. Move them to poorer, well-drained soil and never feed them — lean conditions are the key to blooms.
Sources & review
Written and maintained by the Plants by Zone Editorial Team. Planting times are based on USDA hardiness zones and NOAA frost-date normals, with care guidance drawn from Cooperative Extension sources. Last reviewed June 1, 2026.
USDA Plant Hardiness Zone MapNOAA U.S. climate normalsCooperative Extension
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