Cucumber plants are among the most widely grown vegetables. But what to do when the cucumbers turn yellow and fall off? We clarify.
Causes and countermeasures
If cucumbers turn yellow and fall off, the fault is usually in the care. But diseases and pests also come into question. Read here what you can do about it.
Avoid care mistakes by providing the cucumber plants with optimal conditions in terms of location, water and nutrient supply.
Choose a suitable location
Fruits turning yellow can be the result of unfavorable soil conditions or lack of light. Cucumbers (Cucumis sativus) are shallow-rooted plants whose roots depend on good aeration. In case of corresponding problems, the soil should be made more permeable and humus-rich, as a result of which it warms up faster in spring and does not tend to become waterlogged.
Cucumbers need a lot of heat and at least six hours of sun a day. The less light, the higher the risk of yellowing of the fruit. Potted plants can be moved to a sunnier spot at the first signs. To improve the light output of planted specimens in slightly less bright locations, it is advisable to remove some leaves.
The most common cause of cucumbers turning yellow and dying is improper watering. Because their roots run just below the surface, where the soil first dries out, they need adequate water. However, if the roots are permanently too wet, it becomes problematic for plant and fruit. Particularly heavy soils tend to become waterlogged.
- Suspend watering
- water only when soil has dried well
- Work sand into the soil
- makes it looser and more permeable
- ensures good aeration of the roots
- persistent dryness is also problematic
- mulch layer of straw or grass cuttings recommended
- protects the soil from drying out too quickly, stimulates soil life
Tip: In general, before each watering it is useful to check whether the soil is still wet enough. With formation of the fruits, the water requirement is particularly high.
Ensure nutrient supply
Yellow discolored cucumbers can also be an indication of nutrient deficiency, especially nitrogen deficiency, with yellowing of the leaves as well. Plants concerned show a puny growth, the leaves are much smaller. Fewer flowers are formed and only puny fruits are produced.
- Compensate for deficiency by targeted nutrient application
- Foliar fertilization by spraying with nettle liquid manure
- fertilize with mature compost, horn shavings or horse manure
- or with special fertilizer from the gardening trade
- Check pH value at regular intervals
- Soil must not be too wet
Tip: Cucumbers are so-called heavy feeders, which means that the ongoing nutrient withdrawal throughout the growing season must be compensated by additional fertilizations
Know the harvest time
Once the correct harvest time is passed, the fruits begin to turn yellow. Due to the ending supply, they become firmer, drier and more and more yellow. The kernels or seeds inside also become firmer, darker and reach germination. As soon as the first yellow spots appear, the fruits should be harvested as soon as possible.
Bacterial soft rot
Well-developed cucumber plants often produce masses of fruit, which is further aided by lack of light and periods of bad weather. However, the plants are not able to feed them all optimally.
- young fruits begin to rot at the base of the blossom
- become soft, take on a yellowish tinge and die off
- plant rejects young cucumbers
- thus protects itself from overloading
- whole plant could die
- remove infested fruits promptly
- dispose of in household waste
- keep the plant a little drier
- water only the root area
Tip: If a plant repeatedly produces diseased fruit, it is advisable to remove it completely and dispose of it.
Bugs such as the green rice bug (Nezara viridula) or the marbled tree bug (Halyomorpha halys) are still relatively new in Europe. They also infest cucumbers, among other crops. Yellowish lightening or spots and deformations may occur on the fruit. Promising control in terms of environmental protection and nature conservation is currently not possible. However, in order to decimate the infestation, the animals can be picked off.
Thrips can be particularly dangerous to greenhouse cucumbers. Both the leaves and the fruits turn yellow due to the sucking activity of the pests. The flowers are also infested. Heavy infestation leads to growth retardation and fruit shedding. Beneficial insects such as the predatory bug (Orius laevigatus) and the predatory mite (Amblyseius cucumeris) can be used for control. Glue boards can be used to monitor infestations for early detection and control.
In order to avoid harvest losses due to yellowing and death of the fruit, a number of preventive measures can be taken during the entire cultivation period.
- ensure good soil conditions before starting cultivation
- ensure regular balanced supply of nutrients
- water sufficiently, avoid wet leaves
- observe crop rotation and crop rotation
- plant only every four years in the same place
- do not plant outdoors before mid-May
- protect from cold at the beginning
- mitigate intense sunlight by shading
- ensure constant high humidity and air circulation
- reduce the number of fruit set early on
- strengthen plants with plant liquid manure
Frequently asked questions
Are yellow discolored cucumbers still edible or poisonous?
Completely yellow discolored cucumbers are not poisonous, but due to the change in taste are unsuitable for consumption. The exception, of course, are special yellow cucumber varieties.
When are cucumbers overripe?
Once the first spots turn yellow and the ends are softer than the middle part, they are overripe. At this point, they are usually still edible, but have lost quality.