Courgette: flowers dropping without setting fruit

What it is likely to be on courgette

1. Poor fruit set

   Candidate 1very common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Courgettes and marrows — fruit problems
   • Royal Horticultural Society: Poor fruit set

   Checked 2026-08-13

   A plant that flowers freely and sets little or no fruit. It is the commonest disappointment in fruit growing and it has four quite different causes, only one of which is the plant's fault. Working out which applies is the difference between fixing it and replacing a healthy tree.

   Points towards it

   • · cold wet weather keeps the bees off and holds the female flowers back, and on a young plant nothing needs to have happened at all
   • · a plant under cover has no insects reaching it unless the doors are open, and an outdoor one depends on the weather letting them fly
   • · every flower on the plant behaves the same way, because the limit is pollen and weather rather than anything the plant has
   • · a plant with plenty of water that is still shedding its small fruit is not short of anything it could take up

   Argues against it

   • · a courgette in dry ground sheds fruit because it cannot support them, and watering it is the answer rather than pollination
   • · grey fuzz on the dying flower is a fungus rotting the fruit rather than a failure to set

   Check this next

   Look behind the flower before you look at anything else. A female courgette flower has a miniature courgette between the petals and the stem; a male has a plain thin stalk. If everything opening is male, the plant is simply young — the first fortnight of flowering is usually all male — and nothing is wrong. If females are opening and their little fruit yellow from the tip and shrivel within three or four days, they were not pollinated, and the question is whether any male flowers were open on the same morning and whether bees were flying that week.

   What to do now

   Hand-pollinate on any morning when a male and a female are open together: pick a male flower, strip the petals off, and brush the pollen onto the centre of the female. It takes ten seconds and works reliably. Open greenhouse doors and vents on warm days so insects can get in, which fixes it for the rest of the season. Do not feed or water more in response — a young plant producing only males needs nothing but a fortnight, and two plants rather than one removes the problem in future years.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Courgettes and marrows — hand pollination
   • Garden Organic — Garden Organic (Henry Doubleday Research Association): Cucurbits — pollination

   Checked 2026-08-13

2. Underwatering

   Candidate 2common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Courgettes and marrows — cultivation
   • Royal Horticultural Society: Watering vegetables

   Checked 2026-08-13

   Easier to correct than overwatering and easily confused with it, because a plant short of water and a plant drowning both wilt. The distinguishing observation is not the plant at all — it is the compost, and it takes two seconds to check.

   Points towards it

   • · a courgette carries a very large leaf area over a modest root system and sheds its youngest fruit first when it cannot supply them
   • · a hot week is when demand outruns supply, and the fruit are the first thing the plant lets go of
   • · a dry plant sheds across the whole plant rather than on particular flowers
   • · a container-grown plant does it soonest, and a plant in dry open ground in July does it too

   Argues against it

   • · a plant with plenty of water shedding small fruit is failing to pollinate them rather than failing to feed them
   • · cold wet weather keeps the bees off, which produces the same sign by the other mechanism

   Check this next

   Ask whether the little fruit got bigger before it dropped, then feel the soil. A courgette shed for water swells for several days first and can be finger-length or more when it yellows and goes; an unpollinated one never grows beyond the size it was at flowering. Then push a hand into the soil to a depth of 15cm at the base of the plant — dry there in a hot week, on a plant carrying a square metre of leaf, is the answer, and it will still be shedding tomorrow if nothing is done.

   What to do now

   Water heavily at the base — 15 to 20 litres per plant, twice a week in hot weather, poured slowly so it soaks in rather than running off — and mulch thickly afterwards to hold it. A plant in a container needs the largest pot you have or a move into the ground. Do not water the leaves or the flowers, which invites the fungus that rots fruit tips. Fruit already shed will not come back, and a well-watered courgette sets again within a week.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Courgettes and marrows — watering
   • Garden Organic — Garden Organic (Henry Doubleday Research Association): Watering vegetables at critical stages

   Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on courgette — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general flowers dropping without setting fruit page lists causes across all plants, and the Courgette profile lists the problems it is prone to.