How to grow nasturtium in Australia
Nasturtium is the easiest annual flower you can grow, and one of the most useful. The flowers and leaves are both edible with a peppery rocket-like flavour, the plants attract aphids away from your vegetables (working as a decoy crop), and they self-seed so readily that one planting often becomes a permanent feature of your garden. They tolerate poor soil, dry conditions, and partial shade — give nasturtium too much rich fertile soil and you get lush leaves with few flowers. A bit of neglect is what they want.
When to plant
Nasturtiums are frost-sensitive but otherwise grow in most Australian conditions.
April to August in the dry season.
March to October. Long productive window.
August to May. Most of the year is suitable.
September to May. Wait until after frost risk has passed.
October to April. Frost-sensitive — wait until spring is established.
March to October. Mulch heavily through hot months.
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Open the full planting calendar →How to plant
Nasturtiums are direct-sown — the seeds are large and easy to handle.
Spacing: 25–30cm between plants. Trailing varieties spread to 1m+; bush types stay compact at 30–40cm wide.
Depth: 1–2cm deep.
Soil: Poor to average garden soil. Don't add fertiliser or rich compost — too much nitrogen produces leaves at the expense of flowers. Slightly acidic to neutral pH.
Self-seeding: Nasturtiums readily self-seed. Once you've grown them in a bed, new seedlings appear in subsequent years without intervention. This is generally welcome but can become a weed problem in tidy gardens.
Pots, raised beds, or in-ground?
Nasturtiums are pot-friendly and one of the easiest balcony flowers.
In-ground works for larger plantings or as ground cover under taller vegetables. Trailing varieties cover bare soil and act as living mulch.
Raised beds suit nasturtium well — useful as edging plants or filling empty spots.
Pots are excellent for nasturtium. A 20–25cm pot supports 2–3 plants. Trailing varieties cascade attractively over the edge of pots and hanging baskets. Use a basic potting mix — premium mixes are too rich and reduce flowering.
Sunlight & water
Full sun to part shade — 4 to 8 hours daily. More sun produces more flowers.
Water moderately. Nasturtiums tolerate dry conditions reasonably well. Over-watering produces lush leaves with fewer flowers.
When and how to harvest
Pick flowers and leaves as needed for salads, garnishes, and sandwiches. The peppery flavour is strongest in young leaves and freshly-opened flowers. Pick in the morning when flowers are fully open.
The seed pods (formed after flowering) can be pickled like capers — a small but interesting culinary use.
Flowers don't store well — use within hours of picking. Leaves keep a day or two in the fridge.
Common problems
Nasturtiums have almost no problems. The main issues:
Aphid infestations — actually a feature rather than a bug. Nasturtium attracts aphids away from your vegetables, working as a decoy crop. A nasturtium plant heavily covered in aphids is doing its job; remove and replace as needed.
Too many leaves, not enough flowers is caused by too much nitrogen. Reduce or eliminate fertilising.
Frost damage kills plants overnight. Replant after frost risk passes.
Companion planting
Plant near: Brassicas (decoy crop for cabbage moth and aphids), tomato, cucumber, pumpkin, beans, radish, fruit trees.
Keep away from: Nothing significant.
Australian varieties
Tall Trailing Mix — Long vines (1–2m) suit hanging baskets, climbing low supports, ground cover. Mix of orange, yellow, and red flowers.
Empress of India — Compact bush variety with deep red flowers and dark blue-green leaves. Decorative.
Alaska — Variegated leaves (white and green marbling) on compact bush plants. Mix of flower colours.
Tom Thumb — Very compact dwarf variety (15–20cm). Suits small pots and tight spaces.
Whirlybird Mix — Compact bush type with upward-facing flowers (rather than the typical drooping flower habit). Shows flowers more prominently.