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
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
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.
Grow nasturtiums in your zone
See exactly when to plant and what else to grow alongside nasturtiums, tailored to your USDA hardiness zone.
