Cucumber stem rot is a common disease occurring with our cucumbers and especially the crops grown in greenhouses.

Cucumber Stem Rot Problem

This is a highly deadly disease and can have many causes. Not all of these causes will pose a deadly threat to your cucumbers.

Taking a step back and determining what is exactly causing your stems to rot will benefit your treatment methods.

What Are the Reasons for Cucumber Stem Rot?

Cucumber stem rot would happen because of having fungus in the soil, or due to pests attacking the crops, it would also happen due to poor aeration in the soil, constant watering and soggy soil, or specifically due to root rot.

– Fungus in the Soil

What can distort our plans with the cucumber crops is the appearance of deadly diseases. And one of the deadliest is the rot of the stems or damping off disease, which often leaves our plants unable to recover. It is generally caused by fusarium oxysporum wilt or verticillium wilt, or the presence of phytophthora pathogen in the soil.

Fusarium wilt is another possible culprit of damping-off disease. The symptoms usually include lower leaves turning yellow, and a gradual discoloration of the green parts going up the stem. 

Once your plants begin to produce fruits, they will begin to wilt at speed in the afternoons. Along with fusarium wilt, there can be an offset of the mycelia fungus which will color the stem white, resembling powdery mildew, which is another type of fungus that would impact the growth of the crops. 

If you’re growing cucumbers, you’d want to regularly inspect your plants in the growing season for any signs of wilt, rot, or even beginnings of stunted growth, as all of these can mean an early offset of a stem disease.

– Pests 

This rot can be caused by a variety of pathogens, but your most likely culprit will be Fusarium Oxysporum often already present in the soil, the plant, or being introduced by cucumber beetles.

Reasons for Cucumber Stem Rot

These are the type of pests that will start to eat the crop just as they are growing, and the result would be the stems to grow with malnutrition, hence you will see the stems rotting. You can plant one or more of these 5 plants that can repel the cucumber beetles.

– Poor Aeration

The disease-causing pathogen will most likely already be present in your soil and your plants so it’s only a matter of not activating it.

And the activation situation will most likely be too saturated soil, poor aeration, and high humidity, and this is seen vividly through the stem rot cause and it is a great issue.

– Constant Watering

Apart from a wilted stem or stunted growth, you’d want to inspect if your soil is getting too mushy or wet and check the humidity levels, especially if you’re growing the plants in the greenhouse. As you are overwatering it, you will check that from the early stages, the soil begins to grow fungi, and this is how the stems would be rotting and looking mushy. 

Verticillium rot will be one of your most common causes for future rot problems, and it’s somewhat hard to spot. To be more specific, Verticillium Dahliae will begin by showing yellow and brown spots on the leaves resembling Alternaria leaf blight! 

This is why gardeners may shun this disease, but if your cucumber is sitting in wet soil and spots don’t have any halos around them, then you’re likely dealing with this issue. It would degenrate the crops, in the long run, when you do not take care of it and put a stop. 

– Root Rot

Root rot is yet another common starter of the stem disease, and the one that’s the deadliest and the most silent.

This disease will be triggered by the activation of pythium or Phytophthora Capsici pathogen in the overly wet soil — your roots won’t only have a hard time breathing, but with the lack of air will develop rot, soon spreading to the stem. Unfortunately, when the stem signs begin, it will likely be too late.

How to Treat The Stem Rot in Cucumbers

To treat the stem rot in cucumbers you should provide proper temperature and airflow to the soil, and make sure to use sterilized tools, and grow the crops in raised beds. In addition to this, you should also make sure to treat the infested soil.

All of these symptoms and diseases will eventually kill your plants so the best way to treat these causes is actually treating the soil instead of the plant. That’s why prevention is your best bet, and it’s a matter of adjusting a few parameters.

– Providing Temperature and Airflow

Rots will oftentimes be caused in lower and mid-temperature ranges, and it’s best to fight them by raising the level a bit. If you are growing them in a greenhouse, make sure that the temperature is in the range of 60 degrees Fahrenheit, because this is where fungus won’t be able to germinate any longer, so keeping the growing temperature at around 68 will do you all the good to grow greenhouse cucumbers.

Alongside temperature, high humidity will be another important causal factor of rotting diseases, and in this case, you can battle humidity by ensuring a good enough airflow. Once again, inside-grown plants will benefit from this much more than your outdoor varieties which are already exposed to a healthy amount of breeze.

Treat The Stem Rot in Cucumbers

Always look to improve the airflow in the soil too, and to do this by creating more air pockets in the soil, or adding some form of an inorganic matter to the soil. Air allows your soil to dry out properly and provides oxygen to the root system, ensuring safety from rotting roots, rather than having compact soil.

– Sterilize The Tools

If you’re using contaminated tools to prune your plants you will likely spread fungal pathogens yourself, which is why it is very important that you would sterilize the tools properly.

Whenever you’re about to do any pruning work, or use any plant tools you should first clean them with some rubbing alcohol to kill of any bacteria and fungi.

– Raised Beds

Cucumbers are ideally grown in raised garden beds, and for many different reasons. The very vines of cucumbers will benefit from being suspended mid-air, being constantly swung by the spring breeze. But the most significant feature of raised beds is the actual drainage.

Raised beds will have no problem getting rid of the excess water, thus allowing your soil to breathe and safely avoiding the root rot causing saturation. Cucumis Sativus or cucumbers generally grow up to 18 inches tall when healthy and around eight feet wide, and with the right raisd beds, you will see it growing to its right potential. 

– Treating Infested Soil

If you did have the bad luck of having to battle with fungal diseases, then know that you shouldn’t plant any more cucumbers in the soil before you do some necessary actions.

And it’s basically treating your soil with some kind of fungicide. It is actually better to be using and controlling pathogens with some natural options instead of going with aggressive chemicals. 

Neem oils or other horticultural oils will do great in this regard — mix them with water and generously spray all over the soil. As you apply these organic oils to repel pests, they are one of the most effective products you can find to battle all kinds of diseases and pests and at the same time, grow your cucumbers organically.

Rotting Stem is a Deadly Condition


Cucumbers are a source of our staple crop, and we all love them in our salads and as a side dish.

Let’s check on what we covered today in this article: 

  • Rotting stem is a deadly condition, kicked off by the development of wilts or root rots.
  • This one will likely kill your cucumber vines, so you’d want to get rid of any infected cucumbers and disinfect your soil in addition to your gardening tools.
  • If you’d like to prevent your cucumbers from getting infected, grow them with sufficient light, and aeration.
  • Think about raised garden beds, as these will insure no moisture is sitting inside the container, waiting to start the disease.

Preventing this disease is easy as one, two, and three if you’ll employ the tactics we mentioned here!

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