Nasturtium (Indian cress) care

Light

Nasturtium needs sun on the leaves, not just bright ambient room light. 6 hours of direct sun; tolerates light shade. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water nasturtium weekly watering. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Drought-tolerant once established; over-feeding produces leaf at expense of flowers.

Soil and pot

Nasturtium grows best in free-draining loam. pH 6.1-7.5. Lean soil produces more flowers. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Nasturtium sits happiest at around 40-70% (outdoor) humidity and 15-26°C (60-80°F). Outdoor humidity rarely matters. If you keep the room above 15 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed nasturtium sparingly. None needed; rich soil produces leaf at the expense of flowers. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on nasturtium in the Growli community. Each is annotated with the most common cause so you know where to start.

• All leaves, no flowers — Too rich soil or too much nitrogen.
• Cabbage caterpillars and aphids — Nasturtiums act as a trap crop — leave them and protect the brassicas behind.
• Slow germination — Soak seed overnight; soil must be warm.
• Trailing types take over — Pinch back tips to control.
• Frost damage — Tender; cut back at first frost.

Companion plants

Nasturtium pairs well with Cabbage, Tomato, Squash, and Cucumber. These are species with similar light and water needs, so you can group them in the same room or on the same shelf and water as a batch.

Propagation

Direct-sow after frost; soak seed overnight. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Nasturtium is pet-safe. Tropaeolum majus is not listed by the ASPCA. Considered safe and edible. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Nasturtium deep-dive guides

Every aspect of nasturtium care, each with its own calibrated guide:

• Common nasturtium problems & fixes
• Nasturtium watering schedule
• Nasturtium light requirements
• Best soil mix for nasturtium
• Nasturtium fertilizing guide
• When to repot nasturtium
• How to propagate nasturtium
• How to prune nasturtium
• What's eating my nasturtium?
• Nasturtium growth rate & size
• Nasturtium cold hardiness
• Nasturtium temperature & humidity
• Is nasturtium toxic to cats & dogs?
• Is nasturtium toxic to cats?
• Is nasturtium toxic to dogs?
• All 8 Tropaeolum varieties
• Getting nasturtium to bloom

Featured in these plant shortlists

Nasturtium qualifies for 13 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best pet-safe houseplants — Houseplants the ASPCA lists as non-toxic to cats and dogs — every one verified against the ASPCA toxic and non-toxic plant list.
• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best trailing & climbing houseplants — Vining and trailing houseplants for shelves, hanging pots, and moss poles — selected by growth habit.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best pet-safe trailing & hanging plants — Trailing and climbing plants the ASPCA lists as non-toxic to cats and dogs — safe for shelves and hanging pots in a pet home.
• Best pet-safe low-maintenance plants — Non-toxic to cats and dogs and forgiving of forgotten watering — the easiest safe choices for a busy pet household.
• Best pet-safe flowering plants — Flowering houseplants the ASPCA lists as non-toxic to cats and dogs — colour and blooms in a pet home, without the worry.
• Best pet-safe plants for bright light — Non-toxic to cats and dogs and happy in a bright, sunny spot — safe plants for your best-lit windowsill.
• Best pet-safe large indoor plants — Big, floor-standing houseplants the ASPCA lists as non-toxic to cats and dogs — a statement plant that is safe around pets.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Best cat-safe plants — Houseplants the ASPCA lists as non-toxic to cats (and dogs) — safe greenery for a home with a curious cat.
• Best dog-safe plants — Houseplants the ASPCA lists as non-toxic to dogs (and cats) — safe greenery for a home with a curious dog.
• Browse all 30 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Nasturtium is also known as Indian cress, monk's cress, and garden nasturtium.

• Billy buttons care — light, water and common problems
• White Trillium care — light, water and common problems
• Red Trillium care — light, water and common problems
• All 10153 plant care guides in the Growli library