How to Grow Nasturtium Hydroponically
Nasturtium produces edible flowers, leaves, and seed pods — all peppery, all beautiful. The easiest culinary flower for hydroponic systems.
BY ROOTLESS FARM
Quick answer
Nasturtium (Tropaeolum majus) reaches first flower in 50–60 days from seed at pH 6.0, EC 1.2, DLI 16, and air 18–26 °C. The easiest culinary edible flower for hydroponics — peppery flavor in leaves, flowers, and unripe seed pods. Best in drip or ebb-and-flow systems with mild nutrient regime to encourage flowering.
Conditions
| Parameter | Value |
|---|---|
| pH | 5.5–6.5 (6.0 ideal) |
| EC | 1.0–1.6 mS/cm |
| Air temp | 18–26 °C |
| Water temp | 18–22 °C |
| Humidity | 40–60% |
| DLI | 16 mol/m²/day |
| Photoperiod | 14 h |
| Spacing | 25 cm |
| Days to harvest | 50–60 (first flowers) |
| Yield/plant | ongoing — flowers, leaves, pods for 4–6 months |
Why nasturtium earns rack space
Three reasons:
- Multi-harvest plant. Leaves, flowers, and unripe pods are all edible.
- Peppery flavor. Similar to watercress and radish — light pepper that brightens salads.
- Visual. Bright orange-yellow-red flowers transform any plate. Restaurants pay $20–40 per flat of nasturtium flowers.
Recommended system
Drip with coco coir + perlite — best. The slight drainage encourages flowering over lush foliage.
Ebb and flow — works well.
Dutch bucket — for vining varieties.
DWC — produces healthy leafy plants but fewer flowers. Use a "bloom" nutrient mix to compensate.
NFT / Kratky — adequate for short cycles.
Variety picks
- Jewel mix — classic, compact bush form, abundant flowers. Beginner standard.
- Empress of India — deep red flowers, dark blue-green leaves.
- Whirlybird — semi-trailing, mixed colors, vigorous.
- Variegated Alaska — variegated white-green leaves, beautiful even before flowering.
- Vining nasturtium — climbs 2 m, needs trellis. Less practical indoors.
Light and temperature
- Air 18–26 °C. Tolerates broad range.
- DLI 14–18.
- Photoperiod 14 hours.
- Humidity 40–60%.
Nutrients
Standard 3-part at EC 1.0–1.4 mS/cm during vegetative; drop to EC 0.8–1.0 during flowering to encourage continued flower production.
Key insight: low nitrogen = more flowers. High N produces giant leafy plants with few flowers. Switch to a bloom-ratio nutrient at week 4.
Common problems
- No flowers, lush leaves — too much nitrogen. Reduce N.
- Yellow leaves — natural with maturity; remove. If extensive, may indicate root issues.
- Aphids — common nasturtium pest (aphids love nasturtium; some growers plant it as a "trap crop"). Sticky traps; ladybug release.
- Stretched plants — low light. Boost DLI.
Harvest
Pick flowers, leaves, and unripe pods individually as needed. Continuous harvest keeps the plant producing.
Flowers: pick fully open in the morning. Use immediately or refrigerate 2–3 days. Leaves: pick young (10 cm or smaller) for tender peppery salad addition. Pods (unripe): pick small green pods before they harden. Pickle in vinegar as "poor man's capers."
A single nasturtium plant produces 50–100 flowers + abundant leaves over a 4-month cycle.
See also
- Watercress — peppery cousin
- Mizuna
- Drip system
- Choosing a reservoir
FAQ
4 entries- Q01Are all parts of nasturtium edible?
- Yes — flowers, leaves, stems, and unripe seed pods. The unripe seed pods are pickled as a substitute for capers ("poor man's capers").
- Q02How fast does nasturtium flower?
- First flowers at 50–60 days from seed. After that, continuous flower production until the plant tires (4–6 months indoors).
- Q03Best system for nasturtium?
- Drip with coco coir or ebb-and-flow. DWC works but produces lush leafy growth with fewer flowers. Mild nutrient stress encourages flowering.
- Q04Why won't my nasturtium flower?
- Too much nitrogen. Nasturtium produces leaves with abundant N and flowers when N is restricted. Switch to a bloom-ratio nutrient (lower N, higher P-K).