When to plant Forget Me Not 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 forget-me-nots direct from March to May, scattering seed onto moist soil and covering lightly with about 3 mm of fine mix. In subtropical gardens this autumn window is the key to success — plants germinate in 7–14 days as the heat eases, then grow through the mild winter to flower in early spring, around 80–90 days from sowing. Choose a spot in dappled shade or morning sun, and thin plants to about 30 cm apart in rows 15–20 cm apart. They dislike hot, dry sites, so a cool, moist, shaded corner near Brisbane or Coffs Harbour suits them best.

Sowing calendar — subtropical zone

Green months are your sowing window: March to May.

Growing notes

Forget-me-nots are cool-season plants pushed to their limit in the subtropics, so timing is everything. Sown in autumn they thrive through the mild winter; sown any later and they collapse when spring humidity and heat arrive.

The classic failure here is powdery mildew. In warm, still, humid air the foliage greys over and flowering stops. To keep it at bay:

• Plant in a spot with morning sun and afternoon shade, not deep shade or full afternoon sun.
• Give reasonable spacing, around 30 cm, so leaves dry quickly.
• Water the soil, not the foliage, and do it early in the day.

They love moisture at the roots but hate being waterlogged, so a humus-rich, free-draining bed under deciduous shade or beside taller plants is ideal. In gardens around the Gold Coast they often behave as short-lived plants, flowering hard in spring then fading as summer arrives. Let a few plants set seed and drop it — forget-me-nots self-sow readily and will return each autumn on their own, which is the most reliable way to keep them in a subtropical garden.

Forget Me Not at a glance

Common questions

When should I sow forget-me-nots in Brisbane?

Sow direct in autumn, from March to May, once the summer heat fades. This lets seedlings establish over the mild winter and flower in early spring. Sowing later runs into spring humidity, which brings on mildew and cuts flowering short.

Why do my forget-me-nots get a grey coating on the leaves?

That is powdery mildew, common in warm, humid subtropical conditions. Improve airflow by spacing plants around 30 cm apart, water at the base early in the day, and give them morning sun with afternoon shade.

Will forget-me-nots come back each year in the subtropics?

They tend to be short-lived here, fading as summer heat arrives, but they self-seed freely. Let a few plants drop seed in spring and new seedlings will usually appear the following autumn.

Do forget-me-nots need sun or shade in a warm climate?

In the subtropics they prefer dappled shade or morning sun with afternoon protection. Full afternoon sun in a warm garden stresses them and shortens flowering, while a cool, moist, lightly shaded spot keeps them going longer.

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