First, the reassuring part: if the flowers dropping are on plain, thin stalks, that's normal. Those are male flowers — they open for a day, shed their pollen and fall, and a healthy plant sheds plenty. But in a cool or mountain garden there's a second, real cause that's far more common than in warmer zones: female flowers, each with a tiny courgette behind the petals, dropping unset because cold, wet early summers keep the bees from pollinating them. So here, "flowers falling off" is worth a closer look than it would be up north.

Tell male from female before you decide

  • Male flower: plain, thin stalk, nothing behind the petals — dropping is normal.
  • Female flower: a miniature courgette right behind the bloom — if this yellows, shrivels and drops, that's the problem case.

The distinction matters more in this zone, because a genuinely failed female flower is a real possibility here, not just a rare off-chance.

The most common reasons — for a cool or mountain garden

  1. Unpollinated female flowers dropping — common here. The tiny fruit behind a female flower that didn't get pollinated turns yellow, shrivels and drops. Cold, wet early-summer weather keeps bees grounded exactly when your flowers are open, so in this zone this is a leading cause rather than an occasional one. It's the same pollination shortfall that shows up as courgettes "not fruiting."
  2. Normal male-flower drop. Still happening alongside the above — male flowers last a day and fall. Check the stalk before assuming the worst.
  3. Blossom-end rot from uneven watering. Young fruit that rots at the far end is a moisture problem, from swings between dry and wet soil.
  4. Stress. A cold snap or root disturbance can make a plant shed flowers and fruitlets — more of a risk in a zone where cold snaps are frequent.

Timing and a short season

Courgettes are frost-tender, and the cool/mountain frost period runs March to November — a short warm window. Sown November to February for a January-to-March harvest, the season is tight, so every female flower that drops unset is a real loss. That's the case for intervening early rather than hoping the bees show up.

What to do now

  • Check the stalk first. Plain stalk = male = normal drop. Tiny courgette behind it = female = act on it.
  • Hand-pollinate through December and January as standard practice, not a last resort. Pick a male flower, strip its petals back, and dab its centre into each open female on a sunny morning before about 10am. In this zone, the bees often won't do it for you.
  • Keep watering even and mulch to steady soil moisture, so you're not losing fruit to blossom-end rot on top of the pollination misses.

What to change next season

  • Grow at least two plants so there's always pollen on hand for the mornings bees don't fly.
  • Choose the warmest, most sheltered, sunniest spot to lift both fruit set and what little pollinator activity you get.
  • Water consistently and shelter plants from cold snaps.

For the wider cool/mountain courgette picture — timing, powdery mildew and transplant shock — see the full growing guide below.

More on this zone: Growing Courgettes in NZ Cool/Mountain and Why Is My Courgette Not Fruiting in NZ Cool/Mountain?, or the full NZ Cool/Mountain Planting Calendar →.