Useful information

Why are cucumbers bitter


Cucumber is one of those vegetables that please us with their harvest among the first in our climate. And although in stores today you can buy them all year round, neither by crunch nor to taste, purchased greens will never compare with those that you bring from your own greenhouse or greenhouse at the very end of spring or early summer. And rarely has any of the gardeners had the opportunity to grow a bitter cucumber. Few things are as frustrating as tenderly and lovingly tending vegetables, only to finally collect them and find out that they are not very tasty when you serve them. Cucumbers are known for their fertility, sometimes to the extreme. But what is the use of cucumbers if they are not edible?

What makes cucumbers bitter?

The bitterness of cucumbers is given by cucurbitacin. Cucurbitacins belong to the class of tetracyclic triterpenoids and represent a whole group of structurally similar substances, each of which received, in addition to the main name, an additional Latin letter from A to R. In plants, cucurbitacins are contained in the form of glycosides, which, under the action of the elastase enzyme, break down into free cucurbitacin and sugar.

All cultivated cucumbers contain cucurbitacin B and cucurbitacin C, toxic organic compounds that should make their leaves bitter and less palatable to leaf-eating insects and animals. In addition, cucurbitacin increases the germination and germination rate of seeds, as well as the resistance of the crop to stress. These compounds are usually concentrated in the leaves, stems and roots, that is, those parts of the plant that people do not eat, so we do not know that they are there. Only when they turn into the greens themselves, we begin to feel a bitter taste, although this substance is also present in a sweet cucumber, but in a minimal amount. Because of this feature, in the 18th century, cucumbers were even considered poisonous and were not eaten. Usually, not all of the cucumber turns bitter. More often than not, the bitterness will concentrate on the tips and the area just below the skin.

Note that today cucumber, on the contrary, is considered a medicinal plant and precisely because of the cucurbitacin content. Cucumber helps to improve the functioning of the liver and intestines, and reduces the risk of malignant tumors. Scientific research conducted in different countries of the world since the second half of the twentieth century has proved that cucurbitacins have a wide range of very important biological properties, such as antitumor, contraceptive, anti-inflammatory, antimicrobial, anthelmintic, etc. However, official medicine is not yet ready to call us as prevention or, moreover, treatment of serious diseases, eat bitter cucumbers.

Few people know that not only cucumbers, but also many other plants protect themselves from being eaten by animals using similar mechanisms. For example, plants of such delicious melons as pumpkin, melon or watermelon contain saponin, an organic compound with a bitter taste, akin to cucurbitacin. The very name of the pumpkin family originated from the Latin name for pumpkin - Cucurbita pepo... Moreover, these substances are contained not only in food, but also in non-food representatives of this family, for example, a white step, aka white bryony (Bryonia alba), mad cucumber, or echinocystis lobed (Ecballium elaterium) etc., as well as representatives of other families, for example, eleocarpus (Elaeocarpus hainanensis) etc.

Most of all, unripe fruits and overripe specimens growing in unfavorable conditions, as well as those vegetables that grew from the seeds of bitter cucumbers, are prone to bitterness. Therefore, when planting, choose varieties and hybrids resistant to bitterness and be very careful when selecting specimens for self-collecting seeds.

To the question - what is wrong with the plant, as always, there is no single answer.But this is what makes truck farming and gardening so interesting!

There is no consensus on what causes strong bitterness in the fruits of cucumbers, but all experts agree that the culprit for this phenomenon, which is offensive to us, is this or that type of stress that the plant experiences during growth. Unfortunately, we cannot tell if our cucumber turns bitter while it is still growing. But while we cannot fix the problem before it happens, we can try to avoid further growing conditions that are potential culprits for the bitter taste of cucumbers, and try to get a rich harvest of cucumbers with excellent taste.



Improper watering can be one of the causes of bitterness. A native of the humid warm tropics, the cucumber, although it has settled almost all over the world, is still not able to completely accept the unfavorable living conditions for it. And above all, this applies to the drought of the summer months, which is often encountered in our latitudes. From lack of moisture, the cucumber becomes bitter. In addition, the lack of water will affect not only the taste, but also the appearance of the fruit. Due to the longer ripening, the size of the greens will decrease, and its skin will darken. But the cucumber also reacts to excessive watering, especially with water from a hose, which is too cold for this thermophilic crop, and a strong pressure erodes the soil under the plants, exposing their root system and thereby contributing to the defeat of plants by root rot.

Cucumbers need to be watered so that the soil under the bushes is constantly in a moderately moist state. The amount of watering depends on the established weather and the type of soil on the site. Watering should be done only with warm water heated in the sun, in the early morning or late afternoon. The water temperature for watering cucumbers should be between 22-25 degrees. Cucumbers love to swim, so watering from a watering can with clean water of a comfortable temperature over the leaves will be perceived with great pleasure

For summer residents, a good solution would be to mulch the soil on cucumber beds with a thick layer of weeded out weeds, straw or rotted sawdust. Mulch will retain moisture in the soil longer, and will also protect the root system of plants from exposure.


Excessive or insufficient lighting can also cause the presence of cucurbitacin in zelens. Cucumbers are photophilous, they like bright, but diffused light, direct sunlight burns them in hot weather, plants react to stress with increased production of cucurbitacin. Since a bush can be illuminated by the sun in different ways, on the same bush there may be fruits of different taste: those that were in the shade of the foliage will have a normal taste, and those that overheated in the sun will be bitter. Those cucumbers that have grown in insufficient lighting due to the wrong choice of their planting site, thickening of plants or strong shading by taller neighbors will also taste bitter.

It is necessary to plant seeds or seedlings of cucumbers in the garden at intervals of 20-30 cm in a row and 40-50 cm in aisles. Long-leafed varieties require timely pinching, shoots should not grow more than 1.5-2 m. In the open field, for natural shading of cucumbers on the southern side of the garden, you can plant corn or sunflowers. Cucumbers grown on a trellis can be protected from the hot sun by throwing a lightweight non-woven material over the upper crossbar of the structure.

When growing cucumbers in a polycarbonate greenhouse, the material itself gives it a bright, but diffused light. In the southern regions, the ceiling and walls of a glass greenhouse can be whitewashed or shaded from the outside with special shading nets for greenhouses to reduce sunburn.


The attack of pests (aphids, whiteflies, thrips, nematodes, bear, spider mite, etc.) is one of the possible reasons for the presence of bitterness in cucumbers.Plants will actively defend themselves from the invasion of insects and begin to vigorously produce a repelling bitter substance. It is necessary to carry out preventive measures to protect plantings in time and observe the rules of agricultural technology.

Top dressing

Cucumbers respond poorly to both lack and excess of nutrients. Plants react to "overfeeding" (especially nitrogen) in the same way as to hunger - they give bitter fruits. A lack of nutrients will add to the bitter taste an irregular shape of the fruit and a sick appearance in general.

Cucumber feeding scheme:

  • the first is carried out in the phase of 2-3 true leaves with a mullein solution (1:10) or a solution prepared from 10 liters of water, 10 g of urea, 10 g of potassium salt and 10 g of superphosphate;
  • the second - at the beginning of flowering, an infusion of fermented grass (1: 5) with the addition of 1 glass of ash for every 10 liters or a solution prepared from 10 liters of water, 30 g of urea, 20 g of potassium salt and 40 g of superphosphate; during this period, foliar feeding with a solution of boric acid (10 g per 10 l of water) will also be useful, which will increase the number of ovaries;
  • the third - should be carried out during active fruiting with a solution of 10 liters of water, 0.5 liters of mushy mullein and 1 tbsp. spoons of a complete mineral preparation;
  • the fourth is carried out to extend the fruiting period with a two-day infusion of rotten hay (1 kg per 10 l) or infusion of fermented grass (1: 5) with the addition of 1 glass of ash and 1 tbsp. spoons of baking soda.

Root feeding of cucumbers is carried out in the evening on a pre-moistened soil, pouring 1 liter of nutrient mixture under each bush. Foliar spraying is best done in the evening or early morning hours so as not to burn the leaves of the plants.


Unfavorable weather conditions (sudden changes in day and night temperatures, strong gusty winds, prolonged cold rains) and careless handling of cucumber lashes will become stressful for plants that are acutely responsive to any alarming changes with an increased release of bitterness into the fruit. When caring for plants and harvesting, try not to injure the foliage and shoots, do not turn or twist the whips, carefully pluck the greens.


Since the production of cucurbitacin is a genetic feature of any cucumber, this ability is found in plants of any variety. But older varieties of cucumbers react to unfavorable growing conditions much more sharply than modern varieties and hybrids, endowed by breeders with greater resistance and endurance. By experimenting on your site with varieties and hybrids of cucumbers, you can pretty quickly be able to choose those that work best in your area.

What to do with bitter cucumbers?

There are several ways to remove excess bitterness from harvested cucumbers. The simplest and most common way is to peel a cucumber and cut off its "bottom". However, rinse the knife after each cucumber to avoid spreading the bitter taste. The disadvantage of this method is that most of the nutrients, of course, are in the skin. Another solution is to cut off both ends. Then rub the far end against the open end of the cucumber and continue rubbing until a white foam appears. Continue until foaming is over, and then do the same on the other end of the cucumber. Wash the cucumber quickly - the bitterness will disappear!

Bitter cucumbers can be used for preserving or preparing hot dishes, as when heated, the bitterness disappears in them. But if the vegetables are very bitter, it is better to pre-soak them in warm water.

Selecting the right variety and proper crop care will allow you to get a generous harvest of cucumbers every year without the slightest hint of bitterness.