GrowSabzHow to grow nasturtium in pots
Also called Indian Cress, Monk's Cress, garden nasturtium, capucine · Tropaeolum majus
ناسٹورشیم
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 0.4 Levery 3 days, 5 L pot
- 🌡️ Ideal temp
- 18–24°C
- 🪴 Min pot
- 5 L20 cm deep
- 🧺 Harvest
- 30–45days from sowing
- ⚖️ Yield
- 0.2 kgper 20 L pot
Nasturtium is one of the fastest things you can grow — roughly 45 days from sowing to harvest. That makes it forgiving of mistakes, because a failed sowing costs you weeks rather than a season, and it's a good crop to slot between slower ones.
Short answer
Grow nasturtium in a 5 litre container at least 20 cm deep, watering about 600 ml per 10 litres of soil every 3 days, and keep temperatures between 18 and 24 °C. First harvest comes 30–45 days after sowing.
Where to plant it
What size pot does nasturtium need?
5 litres and 20 cm deep is the realistic minimum for a single plant. Pick a container below to see what changes.
| Container | Minimum size | Depth | Notes |
|---|---|---|---|
| Pot | 5 L | 20 cm | Good drainage is essential. Bush varieties are best. |
| Grow bag | 5 L | 20 cm | Fabric bags provide good aeration and drainage. |
| Open ground | — | 15 cm | Space plants 20-30 cm apart. Trailing varieties can spread widely. |
| Raised bed | 10 L | 20 cm | Provides good drainage and soil control. Ideal for both bush and trailing types. |
Watering
How often should you water nasturtium?
Every 3 days through the growing season, at about 600 ml per 10 litres of soil — daily in hot weather, every 5 days when it turns cool. Water in the early morning. Base watering works best.
Too little water
- wilting leaves
- yellowing leaves
- reduced flowering
Too much water
- yellowing lower leaves
- stunted growth
- root rot
Avoid: overhead watering; soggy soil.
Climate
Can you grow nasturtium where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 18 – 24 °C |
|---|---|
| Survives | 0 – 30 °C |
| Germinates above | 15 °C — best at 20 °C, about 10 days |
| Flowers drop | above 28 °C, or below 5 °C |
| Sunlight | 6–10 hrs/day, best 8 |
| Frost | Highly sensitive — will not survive it |
The flower-drop thresholds matter more than the survival ones. A plant can be perfectly alive at 30 °C and still give you nothing.
How cold is too cold for nasturtium? Check your temperaturesEnter your night low and day high — see if it survives, and if it will cropTimeline
Nasturtium growing stages, day by day
Click any stage to see what's happening. Durations shift with temperature — a warm season runs roughly a quarter faster than a cool one.
Feeding
Fertiliser schedule for nasturtium
Feed on the interval below, changing what you give as the plant shifts from making leaves to making fruit.
| Stage | What to use | Per 10 L | Every |
|---|
How to prepare each feed
Common mistakes
Why nasturtium fails, and how to avoid it
- A container that is too small
Below 5 litres the root run is too shallow. The plant grows, flowers late, and drops whatever it sets because it cannot support the crop.
- Watering too lightly
A daily splash wets the top few centimetres and nothing else. Nasturtium wants about 600 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Ignoring the flower-drop threshold
Above 28 °C, or below 5 °C, flowers fall before setting. The plant can look perfectly healthy and still give you nothing — shade it through the hottest hours.
- Planting it beside Heavy Feeders
Nasturtiums prefer lean soil and do not compete well with heavy feeders for nutrients, especially if the nasturtium is intended as a trap crop. While not directly harmful, it can reduce the vigor of both plants.
- Leaving it out through a cold snap
Nasturtium is highly frost-sensitive. One night below 0 °C can end the plant outright — bring containers in or cover them.
Companions
What to plant with nasturtium
Good neighbours
Acts as a trap crop for aphids and cabbage worms, drawing them away from brassicas like cabbage, broccoli, and kale.
Deters whiteflies and other common tomato pests, potentially improving tomato health and yield.
May improve the growth and flavor of radishes when planted nearby.
Can act as a trap crop for aphids, protecting nearby fruit trees from infestations.
Deters squash bugs and cucumber beetles, protecting cucurbit crops.
Keep apart from
Nasturtiums prefer lean soil and do not compete well with heavy feeders for nutrients, especially if the nasturtium is intended as a trap crop. While not directly harmful, it can reduce the vigor of both plants.
Problems
Nasturtium pests and diseases
Each lists the weather that brings it on, so you know when to start checking rather than reacting once it's established.
Aphids humidity any · temp 15-25
Nasturtiums are highly susceptible to aphids and are often used as a trap crop. Aphids cluster on new growth and undersides of leaves, causing distortion and secreting sticky honeydew.
Cabbage Worms humidity any · temp 18-28
Nasturtiums attract cabbage worms (cabbage loopers and imported cabbageworms), making them an effective trap crop for brassicas. Look for holes in leaves and green caterpillars.
Spider Mites humidity <50% · temp >27
In hot, dry conditions, spider mites can infest nasturtiums, causing stippling on leaves, yellowing, and fine webbing on the undersides.
Whiteflies humidity >60% · temp >25
Whiteflies can be attracted to nasturtiums, especially in warm, humid conditions. They feed on sap, weakening the plant and potentially spreading viruses.
Powdery Mildew humidity 50-70% · temp 20-27
White, powdery patches on leaves and stems, especially in humid conditions with poor air circulation. Can stunt growth and reduce flowering.
Leaf Spot humidity >70% · temp 18-28
Small, dark spots on leaves that can enlarge and merge, often with a yellow halo. Caused by various fungi or bacteria, exacerbated by wet foliage.
Rust humidity >80% · temp 10-20
Small, orange-brown pustules on the undersides of leaves, often with yellow spots on the upper surface. Can lead to defoliation.
Yellowing Leaves humidity any · temp any
Leaves turning yellow can indicate overwatering, poor drainage, nutrient deficiency (rare for nasturtiums), or heat stress. Adjust watering and ensure good drainage.
Harvest
When to harvest nasturtium
First picking falls between day 30 and day 45, and the plant then keeps producing for about 120 days. Pick often — what you leave on the plant signals it to stop making more.
How to tell it's ready
- Tender, vibrant green leaves
- Fully open, brightly colored flowers
- Plump, green seeds (for pickling)
How much to expect
Storing it: Use fresh immediately. Leaves and flowers can be stored loosely in a plastic bag in the refrigerator for a few days. Green seeds can be pickled.
Questions
Nasturtium: common questions
How long does nasturtium take to grow?
About 45 days from sowing to the first harvest, with picking usually starting between day 30 and day 45. It then keeps producing for roughly 120 more days. Warm weather pulls that forward; cool weather pushes it back.
What size pot does nasturtium need?
At least 5 litres and 20 cm deep for one plant. A raised bed wants 10 litres of soil and 20 cm of depth.
How often should I water nasturtium?
About 600 ml per 10 litres of soil, every 3 days in normal weather — daily when it is hot and every 5 days when cool. Water in the early morning.
What temperature does nasturtium need?
It does best between 18 °C and 24 °C and survives from 0 °C to 30 °C. Seed needs soil above 15 °C to germinate, ideally around 20 °C.
Can I grow nasturtium in winter?
Not outdoors anywhere that frosts — it is highly frost-sensitive and will not survive it. In a frost-free winter it grows slowly; anywhere colder, treat it as a warm-season crop.
How do I know when nasturtium is ready to harvest?
Tender, vibrant green leaves; Fully open, brightly colored flowers; Plump, green seeds (for pickling). Once picked: use fresh immediately. leaves and flowers can be stored loosely in a plastic bag in the refrigerator for a few days. green seeds can be pickled.
How much does one nasturtium plant produce?
Roughly 0.2 kg from a 20 litre container, or about 0.5 kg in open ground. Larger containers give proportionally more, up to a point.