When to plant Linaria in Tropical Australia
Tropical zone — applies to Darwin, Cairns, Townsville, Broome, Mackay and similar areas. Growing elsewhere? Temperate · Cool · Subtropical · Arid.
Sow linaria direct from February to June, scattering the fine seed as the wet season eases into the cooler dry months. This hardy little annual, sometimes called toadflax, brings quick colour and germinates in 14–28 days. Barely cover the seed at just 3 mm, as light aids sprouting, then thin plants to 10–20 cm apart with rows 15–20 cm across. Linaria is fast for a flower, reaching bloom in about 70 days, which makes it a good fit for the tropical dry season in Townsville and Cairns, where its dainty snapdragon-like flowers fill borders before the heat returns.
Sowing calendar — tropical zone
Green months are your sowing window: February to June.
Growing notes
Linaria is an easy, quick-flowering annual that suits the tropical dry season well, sown direct from February to June as conditions cool and dry. The seed is fine, so sow it shallowly at 3 mm — light helps germination over the 14–28 day window — and simply press it into a raked, moist surface rather than burying it. At around 70 days to flower, it rewards you fast, making it ideal for filling gaps and edging beds during the cool months.
The main failure mode here is damping-off and rot in seedlings sown too early, while the wet season is still delivering warmth and humidity. Sow into free-draining soil, avoid overwatering young plants, and thin promptly to 10–20 cm so air moves freely between them. Crowded, wet seedlings collapse quickly, so restraint with the watering can matters more than generosity.
Linaria prefers full sun and cooler weather, and it will fade fast once the pre-wet heat builds from October, so treat it as a fleeting dry-season display rather than a long-lasting one. Deadhead spent flowers to stretch the blooming period, and let a few plants set seed if you would like them to self-sow for next year. In Darwin and Mackay, sowing at the earlier end of the window in February to March gives the longest run of flowers before the climate turns against them, though the very earliest sowings carry more disease risk while humidity lingers.
Linaria at a glance
| Sowing depth | 3 mm |
|---|---|
| Plant spacing | 10-20 cm |
| Row spacing | 15-20 cm |
| Germination | 14-28 days |
| Days to maturity | 70 days |
| Frost tolerance | Hardy |
| Method | Sow Direct |
Common questions
- When should I sow linaria in the tropics?
- Sow direct from February to June as the wet season eases into the cooler, drier months. Linaria flowers in about 70 days and prefers cool conditions, so this window gives the best display before pre-wet heat returns.
- How deep do you sow linaria seed?
- Sow just 3 mm deep, barely covering the fine seed, as light aids germination. Press it gently into a moist, raked surface rather than burying it, and expect seedlings in 14–28 days.
- Why are my linaria seedlings collapsing?
- This is usually damping-off, caused by sowing into warm, wet conditions or overwatering young plants. Use free-draining soil, water sparingly, and thin to 10–20 cm so air can move between seedlings.
- How long does linaria flower for in Cairns?
- It is a fleeting dry-season flower that fades once the heat builds from October. Deadhead regularly to extend blooming, and sow at the earlier end of the window for the longest run of colour.
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