Why Is My Cucumber Yellow? Reasons Your Vegetables Are Changing Colors

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If you’re like most people, you probably think of cucumbers as being a light green color. However, sometimes they can turn yellow or even dark brown. So what’s going on? Why is my cucumber yellow? There are several reasons why your vegetables might be changing colors, but don’t worry – none of them are anything to worry about! In this blog post, we will discuss the different reasons why your vegetables might be changing colors and what you can do about it.

Scarce soil

Scarce soil
Photo from @myveggiepatch

Poor soil is one of the main reasons why cucumbers start to turn yellow. In order to understand what your soil has enough and what it lacks, you should do an extensive test. A special soil test can be purchased at any gardening store and they will tell you how to use it correctly. After the soil test, what is important to pay attention to:

  1. Nitrogen – this substance is one of the main causes of yellowing of cucumbers, when there is a deficiency of it in the soil. If nitrogen is not added soon, cucumbers will not only continue to turn yellow, but may die. Adding nitrogen-rich fertilizer at a rate of 5/10/10 will help to remedy the situation. However, on each can there is an exact instruction on how to apply the fertilizer in this or that case.
  2. Potassium – Cucumbers really need potassium after planting and during active flowering. A lot of potassium. Balanced fertilizer with optimal potassium content should be applied to the soil, if it is detected deficiency.
  3. Iron – in addition to the characteristic yellowing on the leaves, they also have green streaks, which is an indication that the plant needs additional iron. You can put liquid iron in the soil, or add special iron pellets that will be released slowly and evenly.

Excessive watering

Excessive watering
Photo from @arcanadulcis

Overwatering can also be a problem for cucumber plants in terms of yellowing of the leaves. When the roots of a cucumber plant are flooded with water, they cannot get the air they need to function properly. The lack of oxygen causes the leaves to turn yellow and eventually die off. If you think your cucumber plants are getting too much water, check the drainage in your pot or bed. If your soil is too dense, you should aerate it and reduce the frequency of watering. Make a watering plan that includes the rainy season. After all, if it rains well, you’ll need to stop watering for a while, depending on the ambient temperature.

The ideal irrigation method for cucumbers is a sprinkler system. It adjusts automatically to prevent your vegetables from drowning. A soaking hose is also a good idea.

Lack of water

Insufficient watering, just as excessive watering can cause cucumbers to turn yellow. The plants may not be getting enough water if the leaves are wilting or the fruit is small and yellowing is common. If you suspect the problem is a lack of water, try increasing the amount of water you give the plants. For cucumbers, 1 to 2 inches of water per week is ideal to thrive and increase in fruit size.

Too much shadow

Too much shadow
Photo from @kriti_clicks93

Before planting cucumbers, it is always important to choose the right location because cucumbers love sunlight. If your plant gets too little light, the leaves can also start to turn yellow. This usually happens gradually, starting with the older leaves at the bottom of the plant, where the yellowing gradually progresses upwards, taking over more and more leaves and fruits.

Cucumbers need at least 6 hours of sunlight a day to grow actively and be healthy. But there are some varieties of cucumbers that need 8 hours of active sun, so it is important to research in detail just your variety of planted cucumbers. Remember that too much sun can burn the leaves and fruit, so think about this point right away as well.

Cucumber diseases that make them turn yellow

There are many diseases of cucumber, but there are some that cause yellowing of the leaves and fruit:

  • Mosaic virus – With this disease, the color of the leaf becomes yellowish dirty with specks of green, like a mosaic, from which the name of the virus derives. The leaf itself after a while begins to wrinkle, its edges become very brittle and often curl down. The infestation comes from contaminated soil, or from aphids, ants, and cicadas. If you accurately determine that a cucumber is infected with mosaic virus, you must carefully pull the affected plant out of the soil and then remove about 10 cm of topsoil beneath it. Everything should then be treated with an insecticide or special soap. Also watch and control the presence of ants, as they are the ones that spread the aphids that cause this kind of virus. Tobacco dust can be used for this purpose;
Cucumber diseases that make them turn yellow
Photo from @agrifacts_
  • Verticillium wilt – first the stems of the cucumber are affected, then the disease moves to the lower leaves, which begin to turn yellow and then wilt. It is not uncommon for the disease to be transmitted from contaminated soil, where the virus can stay for about 10 years. It is important to treat the soil with an insecticide before planting if you are sure that infected plants once grew on it;
  • Fusariosis – yellow and gray spots appear on the leaves, which darken very quickly, and the leaf itself becomes dry and wilting. The root is spoiled first, and then it is transmitted to the leaves and papillae. The disease is transmitted by cucumber beetles as well as by harmful fungi living in the soil. If such a disease is detected, the affected plant should be plucked, the soil should be cleaned and treated with a special agent against fusariosis.

Pests on cucumbers that cause them to turn yellow

Pests on cucumbers that cause them to turn yellow
Photo from @samij102

The most common pests are aphids, whiteflies and spider mites. They drink the sap from the cucumber leaves, so they begin to turn yellow. If not corrected, the bugs will kill your plant. You can spray the cucumbers with insecticidal soap.

There are also problems with potato cicadas, which damage the leaf with their poisonous, watery saliva, leading to yellowing and leaf damage. Ladybugs, lacewings and other bugs that are beneficial in terms of growing cucumbers can help prevent such pests. You can also treat cucumbers with an insecticide.

Nicolas Wayne

Gardening and lawn care enthusiast

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