Cucumber Leaves Turning Brown? Here’s What’s The Matter & How To Fix It

Cucumber plants can be challenging to grow, and they require careful attention. It’s not uncommon for cucumber leaves to turn brown or yellow. Luckily, the problem is usually easy to fix. Read on to learn about the possible causes of cucumber leaf discoloration and how to prevent it from happening in your garden.

Reasons For Cucumber Leaves Turning Brown

There are various reasons why your cucumber leaves may be turning brown. If you’re noticing this issue, it’s essential to determine which of the following causes is to blame.

  • Lack of care: It’s possible that your cucumber plant needs more water or fertilizer to thrive.
  • Vexing verticillium wilt: This soil-borne fungal disease attacks plants’ roots and can cause wilting, yellowing, and dying foliage on cucumbers and other plants in the Cucurbitaceae family (also known as gourds). To prevent this condition, rotate crops each year so they don’t grow in the same location season after season;
    • avoid overworking soil by adding organic matter like compost;
    • avoid planting susceptible varieties close together;
    • mulch heavily around plants during periods when there is no rain;
    • remove any weeds growing near infected areas;
    • apply preventive fungicide sprays at recommended intervals if necessary (check with the local garden center).
  • Diseases that affect cucumber plants: These include bacterial wilt (caused by Erwinia spp.), powdery mildew (caused by Sphaerotheca fuliginea), and downy mildew (caused by Peronospora parasitica), among others. These diseases tend to appear when conditions are favorable for them and insufficiently dry for field crops because weather is either too wet or too dry during pollination stages when moisture levels are highest inside the plant tissues without sufficient airflow gaps between leaves allowing evaporation from above ground surfaces where pollen grains land before entering into stomata openings.

Cucumber Leaves May Be Brown Due To A Lack Of Care.

Cucumber leaves turning brown could be due to a lack of care. This can happen if the plant isn’t getting enough nutrients, water, or sunlight. It’s also possible that there is not enough air circulation around your cucumbers, which can cause them to turn brown.

Your cucumbers need plenty of space for their roots to grow and spread out, so make sure you keep them far away from other plants’ roots by spacing them well apart. You should also make sure that whatever container you’re growing them in has plenty of drainage holes in the bottom, so excess water doesn’t pool up below where it can get trapped and rot some parts of your crop before they reach maturity (which will cause some leaves nearby those areas – especially at their bases – turn brown).

If these factors don’t seem like culprits for why your Cucumis sativus has started turning a sickly yellow-brown color, then we’ll move on to checking whether there may be something wrong with how much light they’re getting;

Vexing Verticillium

If you’re seeing brown or yellow leaves on your cucumber plants, the culprit may be Verticillium wilt. This disease is often confused with Fusarium wilt (which causes wilting and yellowing), but it’s caused by a different fungus.

Verticillium wilt is one of the most common soil-borne diseases that can affect many different plants, including spinach, beans, and tomatoes. While it usually shows up as leaf discoloration in cucumbers, other plant parts like stems and fruit can also turn brown or yellow when infected with Verticillium wilt.

The best way to prevent Verticillium wilt from affecting your cucumber plants is by using non-host resistant varieties of seeds and transplants. If you have some older seedlings that are showing signs of Verticillium wilt symptoms such as yellowing leaves or stunted growth—it’s time to replace them. And remember: It’s not just cucumbers; this fungal disease affects many other types of vegetables too.

Diseases That Affect Cucumber Plants

Cucumber plants are susceptible to a variety of diseases, some of which can be difficult or impossible to cure. Some common cucumber diseases include:

  • Fungal diseases such as powdery mildew, downy mildew, and black rot
  • Bacterial diseases include bacterial speck, pith necrosis, and bacterial leaf spot
  • Viral diseases such as mosaic virus and cucumber mosaic virus (CMV) – this disease causes circular yellow spots on the leaves that then turn brown. The leaves will also turn yellow if you have a lack of calcium in your soil or too much nitrogen fertilizer applied. The symptoms look like those observed with CMV infection but can also occur due to other causes such as over-fertilization or root damage caused by nematodes (tiny worm-like creatures). If you suspect one of these causes to be the culprit instead of CMV infection, then treat accordingly using copper fungicides (copper hydroxide) or neem oil sprays regularly throughout the growing season until harvest time begins so as not to lose yield potential.

Moisture Misstep

If your cucumber leaves are turning brown, you may have a moisture misstep on your hands. As mentioned above, the three most common causes of wilted cucumbers and other plants are too little water (underwatering), too much water (overwatering), and soil that is either too wet or too dry.

That’s why it’s important to make sure the soil around your cucumber plant is evenly moist but not soggy. If there’s standing water in the pot or in between its roots, remove it with a paper towel or cloth and let it drain for an hour before watering again. If there’s not enough moisture getting into the potting mix, add some perlite if you’re using potting soil that contains no peat moss or vermiculite. These two ingredients help retain moisture in pots but don’t hold on their own for long periods of time without some help from additives like perlite added at different stages throughout the growth cycle of any given plant type—and especially when growing plants indoors where temperatures fluctuate more often than those experienced outdoors during summertime months.

Deficiencies Of The Soil

If a cucumber plant is growing in soil with a pH that is too low or too high, it can result in leaf discoloration. If the soil you’re using is acidic, the leaves of your cucumber plants will turn yellow or brown and may develop spots on them. This can also occur if your soil is alkaline due to excessive lime content or ground shells from nearby limestone deposits.

If your cucumber plant’s leaves are turning yellow or brown and wrinkling up along the edges of its leaves, this could be because your soil contains too much sand or clay. The best way to fix this issue is by adding large amounts of organic matter into your garden bed so that there’s more carbon available for plants to use as nutrients during photosynthesis. You should also make sure any irrigation system doesn’t dry out between watering sessions. This prevents roots from getting damaged by being exposed to air when they’re trying their hardest to keep themselves moist enough under hot sun conditions (which causes them stress).

Insufficient Sunlight

Cucumber plants are quite sensitive to sunlight, so if your plant isn’t getting enough light, it can lead to yellowing leaves and even poor growth. If this is the case for your cucumber plant, it may be a good idea to move it closer to a window or invest in some grow lights.

Cucumber plants need at least 6 hours of sunlight per day. That being said, shorter days (fall and winter) will still be okay for your cucumber plants, provided that you’re able to supplement with artificial lighting. Make sure you always provide plenty of water and nutrients so that your cukes don’t go thirsty.

Bacterial Wilt Is Another Common Garden Culprit.

Bacterial wilt is another common garden culprit. It’s caused by a soil-borne bacterium that infects the roots and leaves of plants, causing them to wilt, turn yellow and then brown as they die back. The disease can be transmitted by infected plant parts—including seeds and transplants—so it’s important to keep your cucumbers away from other members of their species.

This disease can be a serious problem for cucumber growers since it can spread quickly through your entire crop if left untreated in order to stop bacterial wilt from taking over your patch, get rid of any deformed plants immediately (they’re likely to have been infected) then water deeply every day until the weather cools off so that new growth develops underground where it’s protected from the bacteria in your soil.

Watering Problems

Watering problems can cause cucumber leaves to turn brown. If the soil is dry, the plant will try to suck moisture from its leaves, and this causes them to wilt and turn brown. If a plant’s roots are overwatered, they will be unable to absorb nutrients as well as they should. This can cause wilting or stunting that gives off signs of dehydration in your cucumbers’ leaves.

Powdery Mildew Is Another Major Cause.

Powdery mildew is another common cause of cucumber leaves turning brown. It’s caused by a fungus that attacks the leaves, stems, and fruit of cucumbers. Powdery mildew is not harmful to humans but can cause severe damage to plants.

Cucumbers, like all plants, require proper care to thrive.

Cucumbers, like all plants, require proper care to thrive. While cucumber plants are easy to grow and generally disease-resistant, they do require regular watering and fertilization, as well as plenty of sunlight. If you’re seeing brown leaves on your cucumber plant or any other leafy green plant, here are some steps you can take to correct the problem:

  • Ensure that your cucumber plant has enough water. Watering too little or too much can cause the browning of leaves. Check the soil in the pot every day with a finger; if it feels dry at all (even on just one side), then water thoroughly until water runs freely from drainage holes in the bottom of the pot (or until the level seems about halfway up sides). If your indoor space gets hot during the summer months—especially if it gets direct sunlight—you may need to be especially vigilant about making sure your cukes get enough moisture so they don’t shrivel up prematurely.
  • Apply fertilizer once a week according to package instructions (usually half strength). Fertilizer will help promote new growth for healthy-looking cucumbers later on down the road when they ripen into fruit form.



Here are some of the most common questions about cucumbers answered:

What is the best way to care for cucumber plants?

The best way to care for cucumber plants is to give them plenty of space and water. Cucumbers are thirsty plants, so make sure that you water them often and keep the soil moist.

How can I tell if my cucumber plant is infected with a disease?

If your cucumber plant’s leaves are turning yellow and then brown, you may be seeing the symptoms of a disease called powdery mildew. Cucumbers are particularly susceptible to this fungal infection, which can spread quickly and cause serious damage to your harvest.

It’s important to recognize these symptoms in order to take care of the problem quickly. If you don’t address it right away, powdery mildew will spread throughout your garden and destroy all of your cucumber plants.

Here’s how to tell if your cucumber plant has been infected with powdery mildew:

  • You’ll see yellow spots on the leaves that turn into brown spots as they get bigger.
  • The leaf veins will also turn brown or black before they fall off completely.
  • You may notice white powder on the ground around your cucumber plants—this is actually spores from the fungus that causes powdery mildew.

Our Final Thoughts Now that you know the causes of browning cucumber leaves, you can take steps to make sure your plants stay healthy. We hope this article has helped answer your questions about cucumber leaves turning brown and how you can take care of them.