Nasturtium 'Alaska' (Variegated nasturtium) care

Light

Most houseplants will scorch where nasturtium 'alaska' thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Full sun, 6+ hours, gives the best flowering and crispest leaf variegation. Part shade is tolerated but reduces blooms and can mute the foliage markings. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

For nasturtium 'alaska' in the ground or in a bed, aim for water to establish, then moderately; let the top dry between waterings, about weekly unless dry. Soak the root zone rather than misting the foliage; deep, less-frequent watering trains roots downward and produces a more drought-resilient plant by mid-season. Drought-tolerant once settled. Keep containers from drying out fully, but avoid overwatering, which favours leaf growth over flowers.

Soil and pot

Nasturtium 'Alaska' grows best in light, free-draining, poor-to-average soil. Blooms most on poor to moderately fertile, well-drained soil at pH 6.0-7.5. Avoid rich or heavily fed ground, which yields leaves at the expense of 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 'Alaska' sits happiest at around 40-70% humidity and 15-28°C (60-82°F). A fuss-free outdoor annual indifferent to ambient humidity. Decent airflow helps keep aphids and leaf problems down. 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 'alaska' sparingly. Do not feed to boost flowers. Use at most a single weak balanced feed on very poor soil; nitrogen-rich fertiliser produces abundant leaves and few 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 'alaska' in the Growli community. Each is annotated with the most common cause so you know where to start.

• All leaves, few flowers — Over-rich soil or feeding produces lush foliage with sparse blooms. Grow lean in poor soil and skip fertiliser.
• Blackfly (aphids) — Black aphids cluster densely on stems and shoot tips. Hose off, squash, or grow as a trap crop drawing pests off other plants.
• Cabbage white caterpillars — Riddle the leaves with holes, as nasturtium attracts brassica-family pests. Remove caterpillars by hand or net plants to keep foliage clean.
• Fading variegation — Heavy shade or very vigorous growth can dilute the leaf marbling. Grow in full sun and lean soil to keep the variegation crisp.

Propagation

Grown from its large seeds. Sow direct after the last frost where it is to flower, or start in pots a few weeks earlier. Self-seeds freely; the variegated trait comes true from saved seed of this stable strain. 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 'Alaska' is pet-safe. ASPCA lists garden nasturtium (Tropaeolum majus) as non-toxic to cats and dogs, and it is edible for people. It is unrelated to the toxic watercress (Nasturtium officinale) despite the shared common name; this true nasturtium carries no recognised pet poisoning risk. 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 'Alaska' deep-dive guides

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

• Nasturtium 'Alaska' watering schedule
• Nasturtium 'Alaska' light requirements
• Best soil mix for nasturtium 'alaska'
• Nasturtium 'Alaska' fertilizing guide
• When to repot nasturtium 'alaska'
• How to propagate nasturtium 'alaska'
• Nasturtium 'Alaska' growth rate & size
• Nasturtium 'Alaska' cold hardiness
• Nasturtium 'Alaska' temperature & humidity
• Is nasturtium 'alaska' toxic to cats & dogs?
• Is nasturtium 'alaska' toxic to cats?
• Is nasturtium 'alaska' toxic to dogs?

Featured in these plant shortlists

Nasturtium 'Alaska' qualifies for 1 curated Growli shortlist — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• 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.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

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Nasturtium 'Alaska' is also commonly called Variegated nasturtium.

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