When to plant Godetia in Subtropical Australia

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

Sow godetia direct from March to June, covering the fine seed with about 5 mm of soil once the summer heat has passed. In subtropical gardens this autumn sowing is the reliable path — plants germinate in 14–28 days, grow through the mild winter and flower in about 80–100 days, producing masses of satiny cup-shaped blooms. Godetia dislikes rich soil and summer humidity, so a lean, free-draining, sunny bed suits it best. Thin plants to about 30 cm apart in rows 30 cm apart. Gardeners around Brisbane and Coffs Harbour get the best show from an autumn start.

Sowing calendar — subtropical zone

Green months are your sowing window: March to June.

Growing notes

Godetia, or clarkia, is a cool-season annual grown at the warm edge of its range in the subtropics, so timing carries the crop. Sown in autumn it establishes over winter and flowers in spring; sown any later it runs headlong into humidity and simply melts.

The standout failure mode here is collapse in rich, wet ground. Godetia flowers best in poor soil — heavy feeding gives lush leaves and few blooms, and in warm, damp conditions those soft plants rot at the base. Keep it lean:

• Don't add manure or high-nitrogen fertiliser; a poor, gritty bed is ideal.
• Water sparingly and let the surface dry between waterings.
• Space at the full 30 cm so air moves and foliage dries quickly.

Stem rot and powdery mildew are the humidity signals to watch for. A sunny, open, breezy position keeps both down. Godetia also resents root disturbance, so direct-sowing and thinning beats transplanting. Once flowering starts, a light trim of spent blooms keeps it going, but expect the whole planting to finish as spring warms into the first humid weeks of summer. For a longer show, make a small second sowing a few weeks after the first.

Godetia at a glance

Common questions

When should I sow godetia in the subtropics?

Sow direct in autumn, from March to June, once the summer heat eases. Plants grow over the mild winter and flower in spring, about 80–100 days from sowing. Later sowings hit the summer wet and rarely perform.

Why is my godetia all leaves and no flowers?

Godetia flowers best in poor soil. Rich, well-fed beds push leafy growth at the expense of blooms, and in warm, humid conditions that soft growth also rots. Grow it lean, in a gritty, free-draining bed with little or no fertiliser.

Can I transplant godetia seedlings?

It is best not to. Godetia resents root disturbance, so sow it direct where it is to flower and thin to about 30 cm apart rather than raising and moving seedlings. Direct sowing gives sturdier, better-flowering plants.

How do I stop godetia rotting in humid weather?

Give it a sunny, open, breezy spot, space plants the full 30 cm apart for airflow, water sparingly and avoid rich soil. Finishing the crop before the humid start of summer, by sowing in autumn, is the surest way to dodge rot.

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