When to plant Yarrow 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 yarrow seedlings under cover from August to November, surface-sowing the fine seed no more than 1 mm deep since it needs light to sprout. Germination is quick and even at around 10 days, and plants reach flowering size in 90–100 days. Transplant seedlings out at 60 cm spacings, with rows 30–60 cm apart, into full sun. Yarrow is a hardy, ferny-leaved perennial that copes well with subtropical conditions around Brisbane and the Sunshine Coast, tolerating heat, poor soil and dry spells once its deep roots are established.

Sowing calendar — subtropical zone

Green months are your sowing window: August to November.

Growing notes

Yarrow is one of the easier herbs to succeed with in the subtropics because it is genuinely tough. It handles heat, drought and lean soil, draws in hoverflies, lacewings and other beneficial insects, and spreads by rhizome into a low, weed-suppressing mat.

The main failure mode here is the opposite of neglect: too much kindness. In rich, well-watered soil yarrow grows soft and flops over, and in the humid wet that soft growth develops powdery mildew and stem rot. The fix is to grow it hard, in full sun and free-draining soil, and to water only when genuinely dry.

Good drainage matters. In heavy clay after summer storms around the Gold Coast the crown can rot, so plant on a slight rise or in a raised bed.

Deadhead spent flowers to encourage a second flush and to stop it self-seeding everywhere, and lift and divide the clump every couple of years to keep it vigorous. Because it spreads by underground runners, edge the patch or grow it in a container if you want to keep it contained rather than letting it colonise the bed.

Yarrow at a glance

Common questions

Is yarrow easy to grow in the subtropics?

Yes, it is one of the more reliable herbs here. Yarrow tolerates heat, poor soil and dry spells once established. The main thing to avoid is overwatering and overly rich soil, which make it soft and disease-prone.

Does yarrow attract beneficial insects?

It does. The flat flower heads draw hoverflies, lacewings and parasitic wasps that prey on garden pests. Planting a clump near vegetables can help balance pest numbers naturally.

How do I stop yarrow taking over the garden?

Yarrow spreads by underground runners and self-seeds freely. Deadhead spent flowers before they set seed and edge the patch, or grow it in a container. Lifting and dividing every couple of years also keeps it in check.

Why is my yarrow flopping over?

Usually too much water or too rich a soil, especially in the humid subtropics. Soft growth flops and then develops mildew. Grow it hard in full sun with lean, free-draining soil and water only when dry.

Keep exploring