Start with the simple check: courgettes carry separate male and female flowers, and a young plant produces only males first, so if every flower is on a bare stalk you just need to wait a week or two for the females (each carries a tiny courgette behind the petals). But in a cool or mountain garden, once female flowers are opening and still not setting fruit, the reason is usually pollination — cold, wet early summers regularly ground the bees just when you need them, and that makes this the zone where you most often have to step in yourself.

Male or female? Check before anything else

  • Male flowers are on a plain, thin stalk with nothing behind them.
  • Female flowers have a miniature courgette right behind the bloom.

All-male flowers on a young plant is normal and needs no fixing. It's the female flowers whose little fruit yellows and shrivels instead of swelling that tell you pollination has failed.

The most common reasons — for a cool or mountain garden

  1. Only male flowers so far. Normal on a young plant — wait for the females.
  2. Poor pollination — the leading cause here. A female flower is receptive for only a few hours on the morning it opens and needs several pollinator visits to set. Cold, wet, windy December and January weather keeps bees grounded exactly when your flowers are open, so genuine pollination failure is common in this zone rather than rare. This is why hand-pollination is often necessary here, not optional.
  3. Too much nitrogen. A lush, leafy plant with few flowers has usually been over-fed — worth ruling out, though pollination comes first in a cold zone.
  4. Shade or crowding. A plant in too much shade, or packed tight against its neighbours, puts out fewer flowers and gives the handful of active bees less chance to find them.

Timing matters more in a short season

Courgettes are frost-tender, and the cool/mountain frost period runs March to November — a genuinely short warm window. Sow November to February and you'll harvest January to March, a tighter run than warmer zones get. Because the season is short, a fortnight lost to unpollinated flowers is a real dent in the crop, so it pays to start hand-pollinating early rather than waiting to see whether the bees turn up.

What to do now

  • If every flower is male, there's nothing to fix yet — the females are simply a week or two behind.
  • Make hand-pollination your default, not your last resort. On a sunny morning — before about 10am, while the female flowers are still receptive — snap off a male, tear its petals away, and brush its pollen-laden centre against the middle of each open female bloom. A single male covers several females, and a dry paintbrush does the same job. Through December and January in this zone, repeating this every few mornings is simply normal practice.
  • Rule out over-feeding — ease off high-nitrogen fertiliser once flowering starts.

What to change next season

  • Grow at least two plants so there's always pollen available on the mornings bees don't fly.
  • Give the warmest, sunniest, most sheltered spot you have — it lifts both fruit set and pollinator activity.
  • Keep watering consistent and don't over-feed with nitrogen once flowering begins.

For the wider picture on getting courgettes through this zone's short, cool season — timing, powdery mildew and transplant shock — see our full growing guide below.

More on this zone: Growing Courgettes in NZ Cool/Mountain and Why Are My Courgette Flowers Falling Off in NZ Cool/Mountain?, or the full NZ Cool/Mountain Planting Calendar →.