When to plant Impatiens in Subtropical Australia

Subtropical zone — applies to Brisbane, Gold Coast, Sunshine Coast, Coffs Harbour, Lismore and similar areas. Growing elsewhere? Temperate · Cool · Tropical · Arid.

Raise impatiens seedlings almost year-round in the subtropics, sowing into trays in any month and transplanting once they are sturdy. Being frost tender they suit our mild, frost-free winters especially well, and the long season means you can stagger sowings for continuous colour. Seed germinates in 14–21 days and needs light to sprout, so press it onto the surface at no more than 5 mm deep. Plants reach flowering size in 80–100 days. Space them 30–40 cm apart with rows around 20–30 cm to fill shady Brisbane and Gold Coast beds with soft, non-stop bloom.

Sowing calendar — subtropical zone

Green months are your sowing window: January to December.

Growing notes

Impatiens are made for the subtropics: they love warmth, hate frost, and thrive in exactly the moist, shaded positions where many other flowers sulk. Give them dappled light or morning sun with afternoon shade, a rich soil kept evenly moist, and they will flower for months on end. In Coffs Harbour and Lismore courtyards they are a reliable filler for that shady spot under a tree or against a south wall.

The one serious threat is downy mildew, which has become widespread and hits the common bedding impatiens hard. It shows as yellowing leaves, a white felt on the undersides, then sudden collapse and leaf drop, and it is worst in the humid wet season with warm nights and still air. The fixes are prevention-first: space plants generously for airflow, water at the base early in the day, avoid overhead irrigation, and remove and bin any affected plants promptly rather than composting them. If mildew has ruined a bed before, switch to New Guinea impatiens or SunPatiens types, which are far more resistant.

Beyond mildew, watch for the plants going leggy in too much shade and for wilting on hot, bright days when the soil dries. A light trim keeps them bushy, and steady moisture prevents the midday flop that scares first-time growers.

Impatiens at a glance

Common questions

When can I plant impatiens in Brisbane?

You can raise seedlings almost year-round in the subtropics thanks to the frost-free winters. Stagger sowings every few weeks for continuous colour, and simply avoid transplanting into the hottest, driest part of summer without shade and water.

Why are my impatiens leaves turning yellow and dropping?

This is usually downy mildew, which is common in humid climates and shows as yellow leaves with white felt underneath before the plant collapses. Improve airflow, water at the base in the morning, and remove affected plants to the bin. Resistant New Guinea impatiens or SunPatiens are a safer choice in bad areas.

Do impatiens need sun or shade in the subtropics?

They prefer dappled light or morning sun with afternoon shade. Full subtropical sun scorches and wilts them, while deep shade makes them leggy and shy to flower. A bright but sheltered spot is ideal.

How do I keep impatiens flowering all season?

Keep the soil evenly moist, feed lightly, and give a gentle trim if plants stretch. Steady moisture prevents the midday wilt, and good airflow keeps mildew at bay so the display carries on for months.

Keep exploring