When to plant African Marigold 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 African marigold direct from July through to February, with a break over the coldest weeks of winter, dropping seed 8–12 mm deep into warm, free-draining soil. Germination takes 14–28 days, so keep the bed evenly moist while you wait. Space plants 20–40 cm apart in full sun and expect flowers in 80–90 days from sowing. In the subtropics around Brisbane and the Gold Coast the long warm season lets you stagger sowings for near year-round colour, making this one of the easiest bedding annuals to establish direct.

Sowing calendar — subtropical zone

Green months are your sowing window: July to February.

Growing notes

African marigold thrives in the subtropical warmth, but the region's humidity is where most crops come unstuck. In a wet Coffs Harbour summer the flower heads hold moisture and rot from the inside, going grey and mushy before they open fully.

The fix is airflow and restraint with the hose. Space plants at the wider end of the 20–40 cm range, water at the base in the morning rather than over the foliage, and deadhead spent blooms promptly so decaying petals do not seed fungal problems. A gravel or coarse mulch keeps soil splash off the lower leaves.

Spider mites and two-spotted mite can flare in dry spells between storms, stippling the leaves silver. A firm hose-down of the undersides usually knocks numbers back before they build.

Marigolds prefer lean soil. Rich, over-fertilised beds give you lush leaves and few flowers, so hold off on high-nitrogen feeds and let the plant work a little for its blooms.

African Marigold at a glance

Common questions

When to plant marigolds in Brisbane

You can sow African marigold direct across most of the year in Brisbane, from July through to February, pausing only in the coldest mid-winter weeks. The generous warm season means you can stagger sowings a few weeks apart for continuous colour.

How long do marigolds take to flower from seed

Expect flowers in 80–90 days from sowing. Germination alone takes 14–28 days, so keep the bed warm and evenly moist through that early stretch to stay on schedule.

Why are my marigold flowers going mushy and grey

That is usually botrytis rot, driven by subtropical humidity sitting in the dense flower heads. Improve spacing and airflow, water at the base in the morning, and deadhead spent blooms quickly so decaying petals do not spread the fungus.

Do marigolds need rich soil

No. Marigolds flower best in lean, free-draining soil. Heavy feeding produces leafy plants with few blooms, so skip high-nitrogen fertiliser and let them run a little hungry.

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