First of all: It is not up to you and usually not your cucumber care, but the cucumber. The small water-rich vitamin bombs have two reasons to refuse to produce a fruit – both of which quite often lead to more or fewer flowers, but never fruit.

Too little sun and warmth

Cucumis sativus, the botanical name of the cucumber, comes from the cucurbit family, and the cucurbits all originally developed in tropical and subtropical climates. The home of the cucumber is thought to be in India; It is certain that they were there around 1500 BC. Was domesticated and spread from India to all warm areas of the Old World.

In Iraq, descriptions of cucumbers have been found dating from around 600 BC. The cucumber was proven to be around 200 BC in the Mediterranean region. Arrived in BC, the “ancient Romans” protected cucumbers for Emperor Tiberius (14-37 AD) behind glass walls when they didn’t like the bad weather on the northern borders of the Roman Empire. From there, it took the cucumber 17 to 18 centuries until it was the “original German vegetable” that covered the Spreewald with greenery.

The cucumber is no more indigenous to us than pumpkin, melon and zucchini; However, in culture it has proven to be the most cold-tolerant cucurbit, which is even grown in Northern Europe today. There, however, usually in the greenhouse, because the memory of the warm home of the cucumbers has not yet really been driven out (bred away).

Cucumbers still need a lot of warmth, which determines their thriving from sowing to harvest:

  • The sowing of cucumbers for the open field should take place in all “normally warm” regions of Germany under glass or foil
  • Without this preculture, the young cucumbers in the garden often succumb to the spring weather immediately
  • Or the weak young seedlings are immediately eaten by snails
  • So sow in pots with potting soil from the end of March
  • Germination temperature at least 24 ° C, ideally 25 to 28 ° C, day and night, do not water with cold water
  • Germination time 1–2 weeks, after a further 2 weeks the first leaves appear
  • Only when the outside temperature does not drop below 15 ° C at night can planting be carried out outdoors
  • In most regions of Germany, the cucumbers are only allowed outside after the ice saints in May
  • After carefully accustomed to the field conditions
  • Well-insulated preculture glass beds are covered during the day
  • Pots dressed in protected rooms are allowed outside by the hour
  • In very mild regions of Germany, cucumbers sown outdoors have a chance from May
  • Only at this time should young plants from the weekly market be planted in the garden
  • Unfavorable weather conditions quickly lead to the plant rejecting the female flowers
  • Only the male flowers remain on the “trembling cucumber”
  • Which spares itself so that it will be fit for reproduction in later, better times
  • This can happen if the location is not sunny enough
  • Or if the cucumber plants are not supplied evenly or with too little water
  • Or if it is too cold (day temperatures below 18 ° C, night temperatures below 12 ° C)

If the cucumbers freeze during cultivation, they do not even create any (female) flowers; if later everything does not fit, the fruit-forming flowers are thrown off – in all of these cases you will eventually see mostly (male) flowers, but hardly any or no fruit.

Remedy:  There is not much that can be done sensibly against the weather outdoors, in the greenhouse you can turn up the heating; if the cucumbers continue to grow warmer and sunnier and / or if you water more, female flowers may appear. They’ll definitely bring a few (tiny) cucumbers. Or maybe there are female flowers, and it’s because of pollination.

Lack of pollination

The cucumber, botanical name Cucumis sativus, belongs to the cucurbit family (like pumpkin, melon, zucchini, to which it is closely related). The majority of these cucurbits are originally monoecious, including the original cucumber. Monoecious means that they produce male and female flowers on a plant (opposite: dioecious, only one genus per plant).

On the young cucumber plants, only the male flowers appear first in the leaf axils; usually several flower approaches in one armpit, of which only one comes to flower. The female flowers only appear a good bit later, when the plants have become stronger. They stand individually and not only have a stem, but also an elongated, thickened ovary under the flower. Since the yellow calyxes of the male and female flowers look exactly the same, what matters is this ovary, it is basically a tiny cucumber under the flower – which, however, can only develop if it has also been pollinated.

Insects are needed for pollination, but they have declined dramatically in the last few decades of intensive, chemical-based agriculture. Scientists studied the decline in 60 non-contiguous protected areas for 27 years and found in October 2017 that more than 75% fewer insects populate our environment ( And those were only investigations in unpolluted protected areas, at the “place where it happened” itself, the pesticide-impregnated fields, such a long-term investigation is difficult to carry out.

Pollination is therefore no longer guaranteed at the moment, and there will be problems with the insects for as long as the last (small) gardener understood that he, too, is needed to save insects. At the same time, of course, agriculture should also be moved back to human and environmentally friendly production, but the discussion of the profit interests involved in this area could take too long. If the carefully cherished cucumbers bloom eagerly and male and female, but the flowers are not pollinated (= pollen from male flowers comes on the stigma of the female flowers), no fruit can develop.


  • In the long term, there will be a lot of insect plants in the garden, which are best located around the cucumbers and attract pollinators in large numbers
  • You can help for the current season by shaking the flowers several times a day
  • If you want to be sure, you can emulate Chinese fruit growers:
  • Stick a fine hairbrush into the male flower and pick up a few yellow dust grains
  • Scrape this dust into the female flower
  • If this happens in summer, the pollen will get on the stigma in time for a small cucumber crop to ripen

When the “cucumber drama” takes place in the greenhouse, you should definitely note that the “mixed flowering” cucumbers urgently need the insects for pollination, so they must not be locked out. Since it can take a while until enough insects have settled in the area again, there is an alternative (which, however, will not necessarily satisfy gourmets):

Not every type of cucumber needs pollination

Commercial cucumber cultivation has long been working on cultivating cucumber varieties with more female flowers, which then all form fruits. In more than three millennia of cucumber cultivation, there was some time for experiments – in the meantime, modern breeding work has created cultivated varieties with predominantly female flowers and then purely female-flowered cucumbers in addition to the original mixed flowering varieties.

The more female flowers, the higher the yield; these breeding successes therefore dominate commercial cultivation. Mostly they are smooth-skinned cucumbers, the usual “long greens” from the supermarket and only suitable for greenhouse cultivation. Seeds for outdoor cucumbers, which are grown much less often for sale (which are marketed as land cucumbers) and the commercially used pickling cucumbers and peeled cucumbers for outdoor cultivation, are available, but not to be found everywhere. If you grow cultivars used for commercial purposes, greenhouse cucumbers should really be grown in the greenhouse and outdoor cucumbers outdoors, deviating experiments with these sensitive special cultivations are usually doomed to failure. The varieties are predominantly female:

  • Darina, land cucumber for cultivation in tunnels and in the field
  • Dasher II, land cucumber with above-average regenerative capacity and therefore a lot of yield potential

The varieties with all-female flowers are interesting from a pollination point of view because they are usually parthenocarp (virgin fruit), i.e. they do not need any fertilization at all. They include the varieties:

  • Corentine F1 offers up to 50 pickling cucumbers to one plant at the same time
  • Flamingo F1, greenhouse cucumber with 30 to 35 cm long fruits
  • La Diva can be harvested as a mini cucumber from a young age of 12-13 cm

These cultivars may not be mixed when grown in the greenhouse and may not necessarily stand next to each other outdoors. Normally flowering cucumbers need insects for pollination; Virgin cucumbers should rather not come into contact with insects and thus with pollen from normal cucumbers, because they will then set seeds again and possibly form bulbous, crippled fruits. When these delicate cucumbers shed their female flowers, any slight mistake in care can be to blame. You can just go through everything one by one and choose a more robust strain the next time.

With regard to the other characteristics, these commercially grown varieties are not that remarkable. You know the taste from the supermarket, the resistance is usually so low that pesticides have to be used for commercial cultivation. Many of the modern varieties are now even offered in refined quality, which is due to the fact that these cultivated varieties are no longer able to survive well on their own roots.

If you grow your own cucumbers because you miss the taste of supermarket cucumbers, you should probably stick to the old cultivars, which are much more robust and are available in a variety of varieties by dedicated gardeners. They do need pollination, but anyone who wants to eat fruit and vegetables in the future should do something for the insects to survive. Incidentally, the male flowers are not pointless, but can be plucked and consumed as long as they are not needed to pollinate female flowers.

Cucumbers need warmth and cucumbers need pollination. Self-fertilizing cucumbers are now available, but they are not always satisfactory because they may lack taste and / or resilience. The most recommended solution to the cucumber dilemma will help the cucumber, your garden and the world: Plant many nectar-rich plants for insects next to the cucumber, then it will also work with the pollination of the cucumber blossoms.

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