Bitter cucumbers are not a varietal characteristic, but a cry from the plant that you are making fatal mistakes.
Bitterness is caused by cucurbitacin, a substance that accumulates in fruits due to stress.
And most often this stress is provoked by improper watering. Cucumbers are 95% water, but this does not mean that they should be flooded like a swamp.
The first rule is water temperature. If you water cucumbers with cold water from a hose, their roots experience shock. This slows down the absorption of nutrients and triggers the production of cucurbitacin.
The water should be at least +22°C. Fill the barrel in the morning so that it warms up in the sun by evening, or add boiling water to it before watering.
The second secret is the time of day. Watering at midday, when the sun is active, leads to moisture evaporation and leaf burns. Water cucumbers only early in the morning or after sunset, so that the water has time to soak into the soil.
Watering depth is another critical factor. Cucumber roots are located in the upper soil layer (15–20 cm), but many gardeners only water the surface. As a result, the plant suffers from thirst, and the fruits are bitter.
Check how deep the water penetrates: an hour after watering, stick a wooden stick into the soil. If it only becomes wet for 5-10 cm, you are not watering enough. The norm is 10-15 liters of water per 1 m² of the garden bed.
Cucumbers hate chaos. If you water them every day or once a week, the plant does not have time to adapt. Make a schedule: during the growth of the vines (before flowering) - every 3 days, during fruiting - every 2 days.
In rainy weather, reduce watering, but do not stop completely: natural precipitation is often not enough to soak the soil to the required depth.
Mulch will be your salvation. Cover the soil with a layer of straw, rotted sawdust or mown grass 7-10 cm thick. Mulch not only retains moisture, but also stabilizes the soil temperature, protecting the roots from overheating during the day and hypothermia at night. However, avoid fresh grass with seeds - it will provoke the growth of weeds.
The mistake that turns cucumbers into “bitter enemies” is watering at the root. A strong stream washes away the soil, exposing the roots and damaging the tender roots. Use a watering can with a spray or pour water into furrows at a distance of 10-15 cm from the stem. If cucumbers grow vertically on a trellis, install drip irrigation - this is an ideal way to deliver moisture directly to the roots without stress.
In hot weather, cucumbers often wilt, and there is a temptation to water them additionally. Do not give in! Leaves lose turgor due to overheating, not due to lack of water. Spray them with cool water or shade them with spunbond. But do not increase the volume of watering - this will lead to root rot.
The last secret is fertilizing. Even with ideal watering, cucumbers will taste bitter if they lack potassium. Once every two weeks, fertilize them with ash infusion (200 g per 10 l of water) or potassium sulfate (15 g per 10 l). But apply nitrogen fertilizers (urea, manure) only at the beginning of the season - their excess makes the fruits watery.
