9 Causes of Zucchini Plant Leaves Turning Brown [How to Fix]

Zucchini plant leaves turning brown is a common problem for gardeners; it is caused due to overwatering, root damage, sunlight issues, moisture deficiency, lack of nutrients, temperature fluctuation, pest infestation and disease attacks.

If you are searching for a solution to such brown leaves in your plant, then you are at the right place. Similarly, I also faced this problem which I sorted out using some techniques. I am going to describe them in this article. So, you can also check them and pick them up if you think it is useful.

For your convenience, I have enlisted them in this chart to present the solution shortly.



Sunlight issuesProvide 6-8 hours of full sunlight
Lack of moistureUse a  humidifier to increase humidity 
Underwatering Water your plant when one inch of the soil gets dry
Temperature fluctuation Keep the temperature between 65-70°F
Root damage Stop overwatering and repot the plant
Nutrient deficiency Apply fertilizers to your plant
Poor soil condition Slightly acidic,  nutrient-enriched and well-drained soil is needed
PestsUse industrial insecticides or homemade solutions
DiseasesUse bactericide, fungicide or homemade recipes 

Why Are My Zucchini Plant Leaves Turning Brown? – 9 Common Causes With Remedy

Zucchini Plant Brown Leaves Problem

1. Sunlight issues

As you know, zucchini plants are sensitive to sunlight. Hence, if you notice brown leaves in your zucchini plant, you should check the light intensity that you have made available for your plant. 

If they don’t get enough sunlight, the zucchinis may not develop properly. Again, you may notice yellow leaves or brown leaves in your plant in absence of perfect sunlight. 

Control measure

Zucchini plants need 6-8 hours of full sunlight for their squash improvement and plant development. But you have to make sure that this sunlight should not burn the plant leaves. 

The best sunlight needed for the zucchini plant comes in the early morning. In that period, the plant gets full sunlight without having scorching heat. But try to keep your plant in such a position so that after full-day sunlight, it can remain in a shady place during the afternoon when the sunlight may burn the leaves.

2. Lack of Moisture

The next one is moisture deficiency. As I have explained earlier, a zucchini plant needs sunlight. So, according to this necessity, it always requires enough moisture in their soil. 

Due to a lack of moisture, the leaves don’t get enough water for their photosynthesis or food production. As a result, they cannot complete their normal body functions and the leaves become brown or yellow. 

Control measure

Use sandy loam soil for your plant which can retain enough moisture in the soil. Make sure that the drainage system is perfectly maintained so that the soil remains wet having moisture but water doesn’t stand there. 

Else, I can suggest you a humidifier to increase the humidity of the plant that I applied to my zucchinis. You may spray or sprinkle water on your plant if the moisture of the leaf surroundings has decreased.

3. Underwatering

After that, I want to describe the underwater problem. It indicates the absence of enough water that is caused if you don’t water your plant according to weather conditions. 

The lack of water creates stress inside the plant and the plant cells cannot retain enough fluid inside them due to the continuous process of transpiration. Hence, the whole plant starts wilting and the leaves become brown. 

Control measure

It needs watering when around 1 inch of the soil gets dry. The summer season requires more watering. I used to water my plant once every two days on hot days. But this schedule changed in winter. You may require watering once a week in cooler periods. So, you have to be conscious of your weather in case of watering.

You can pinch your finger in the soil and then check the soil water condition. Thus, you will get the perfect idea to water your plant. (Our Pick: SONKIR Soil pH Meter, MS02 3-in-1 Soil Moisture/Light/pH Tester)

4. Temperature fluctuation

Along with the underwatering problem, temperature fluctuation can also be deteriorating your plant. Too much temperature increases the transpiration rate as well as other body activities. In that period all the body activities are enhanced. 

If a plant cannot get enough water according to this body necessity, it starts to weaken from the inside and the leaves start browning as a symptom of water stress.

On the other hand, too low temperature also hampers the body’s activities. In case of freezing temperature, the plant cannot uptake water due to a frost problem which is called physiological drought. The leaves also get brown or pale in color during that period.

Control measure

Try to maintain the temperature range between 65-70°F in your plant microclimate. If the outside temperature is much, provide polythene shading or keep your plant inside where it won’t face excessive temperature. 

Further, in case of low temperatures, make your plant in a warm place inside your house. Frost should not fall over the zucchini leaves.

5. Root Damage

After that, let’s talk about the root damage which I faced so badly. Even one of my zucchinis died due to root damage which is caused by overwatering. 

When you water much of your plant, the excess water cannot reach the leaves as the needed amount of water is already present in the leaves for food making. Then, the excess water stands in the root zone and different microbial activities take place there. That’s why the roots get damaged and the plant becomes weak showing brown leaves.

Control measure

If you notice that the plant is getting weak and the leaves are becoming brown with wet soil conditions, firstly stop watering your plant. If you still get that the leaves have not stopped browning, then be sure the root damage problem is in severe condition. 

Then, go for repotting. Uproot the plant from the existing pot, prepare a new pot with a nutritious soil mixture, and then plant it in that soil. Thus, you may save your plant which I also saved my other plants.

6. Nutrient Deficiency

Thereafter, I will give you hints about nutrient deficiency. Well, this problem also was about to kill my plant, but luckily I understood the issue and could save my plant. Nutrients, especially, potassium, phosphorus, and nitrogen deficiency may cause dangerous harm to your plant. 

The plant leaves become yellow and brown. As the plant becomes weak in this scarcity, pests and diseases get many opportunities to enter the plant and harm it. So, it will demolish your plant in two ways. 

Control measure

Well, though it has a dangerous effect, you can easily sort out this problem. Use liquid fertilizers in your plant by diluting a few drops of fertilizers in 1 gallon of water. 

7. Poor Soil Quality

Next, you should also be responsible for your soil quality. Inappropriate soil conditions may also cause brown leaves. As the proper supply of nutrients and water becomes almost impossible in infertile soil, the plant cannot properly run its functions.

Control measure

The soil condition should be slightly acidic and full of nutrients. You can use coco-peat, perlite, or sphagnum moss with your soil to facilitate plant conditions. Along with this, the soil should be sandy loam for enough moisture quality. 

8. Diseases

Apart from those problems, I also faced some diseases in my zucchini plant which are-

  • Downy mildew 
  • Cucumber mosaic virus
  • Fusarium wilt 

Control measure

To get relief from disease activities, the first thing you should do is remove the extremely affected parts from your plant. It will prevent the spreading of diseases in healthy parts. 

Following that, you can conduct a heavy stream in your plant which may remove the spores of the organism. Then, you can apply homemade recipes or industrial fungicides or bactericides. 

If such industrial chemicals are available to you or you are in a hurry, spray them on your plant diluting them in the water. Otherwise, prepare homemade recipes for your plant. Here I am including some ideas about homemade recipes that I usually apply to my zucchini plant. 

  • Recipe-1: Baking soda solution 

Use 4 tablespoons of baking soda in 1 gallon of water and spray it on your plant after mixing them properly.

  • Recipe-2: Neem oil solution 

Mix 1 tablespoon of concentrated neem oil, a few drops of essential oil, ¼ tablespoon of aloe vera powder, and 1 tablespoon of liquid soap in 1 gallon of water and spray it on the plant.

9. Pests

Finally, I want to conclude the list of zucchini plant browning causes with pest attacks. Pest attack is much related to disease attack. Pests create wounds in the plant and facilitate disease in those parts. Some common insects of zucchini plants are

  • Spider mites
  • Squash vine borer
  • Squash bug

Control measure

If the pest attack is in the initial step and is smaller in number, try to remove the insects by hand picking. If they are in larger numbers and hand-picking is impossible then use industrial insecticides or homemade solutions. 

I have narrated the homemade solutions that I generally use in my plant. Apart from those, you can also use liquid detergent or other disinfectant liquids available to you. 

If you want to use industrial insecticides, then spray them on the plant according to the method described in the disease control measure.

Some Other Zucchini Plant Problems

Zucchini Plant Brown Leaves With Black Spots

Sometimes, you can see brown leaves with some black spots on the upper surfaces of the leaves. This is a common symptom that may make you sure of a pest attack. 

You may notice whitish small insects in the lower surfaces of the leaf veins which are mealybugs. These insects secrete a sugar substance as their excretory matter which falls on the upper surfaces of the immediate lower leaves and creates black spots which inhibit photosynthesis as it covers the green surface by black spots. 

If you don’t take proper steps, these black spots will be larger and much in number and will hinder the normal activities of the plant. In this stage, you have to take initiative measures to 

Zucchini Plant Yellow Leaves

Again, you may get yellow leaves along with brown leaves. Yellow leaves will indicate a deficiency of nutrients as well as excessive temperature problems. 

As an absence of nitrogenous materials creates chlorosis, it makes the leaves yellow. In extreme cases, other nutrients also start to become low in an amount that initiates brown leaves. Too much temperature or sunlight also burns the pigments of the leaves and makes the leaves brown.

How Can I Revive My Zucchini Plant From Browning – Caring Guide

How To Prune a Zucchini Squash Plant

To revive your plant from brown leaves and make the plant vigorous again, you should follow some steps. You may pick up your solutions or may try the following which benefited my plant.

  • Pruning

The first one is pruning. Pruning means the removal of plant parts especially the foliage parts from the plant. Sometimes, root pruning is also done if necessary but this needs technical knowledge and skills. 

Remove one-third of the foliage of your plant. You should remove the brown leaves from the plant as they won’t provide any benefit to your plant but rather affect your plant more.

To keep your plant more vigorous, you can conduct a regular pruning method every 6 months. This will initiate new foliage growth which will be stronger and more resistant to problems. 

  • Transplanting

The second one is transplantation. It is done when the existing soil medium gets adverse for plant development due to overwatering or root-related problems.

In this session, you should uproot your plant and keep that in a new pot prepared with a nutritious soil mixture. This will make a comfortable zone for the plant to cope with the environment and revive from the problems.

  • Maintaining Microclimate

The final one is maintaining the microclimate of the plant. That means you should provide proper sunlight, temperature, humidity and moisture to your plant surroundings so that it can capture its necessary products from the environment. 

If you are confused about how to provide a perfect environment for your plant, then go back to the causes section of this article and find out the way of maintenance you want to know. If it is preferable to you, you may apply it to your plant.

  • Optimum Requirement

SoilSlightly acidic, sandy loam and nutrient-enriched soil
WateringWater when one inch of the plant gets dry
Temperature 65-70°F
Sunlight6-8 hours of full sunlight 
Humidity Around 60%


Q: Do zucchini brown leaves lead to the death of the plant?

Ans: Yeah, it can! If you don’t sort out the problems of your plant, gradually it will die due to the detrimental effects of different problems.

Q: Can I save a zucchini plant with brown leaves?

Ans: If the cause of the browning leaves is not addressed in a timely manner, the plant may not recover. However, if caught early enough, steps can be taken to save the plant. Remove any affected leaves and improve the plant’s growing conditions by adjusting the watering schedule, ensuring proper drainage, and addressing any pest issues. Additionally, fertilize the plant with a balanced fertilizer to promote healthy growth.

Q: Can zucchini brown leaves turn green again?

Ans: No. Brown leaves normally cannot turn green again. You may protect your green leaves from browning but discolored leaves cannot be turned into normal leaves. That’s why they are better to be removed.

Q: Can zucchini leaves may brown naturally?

Ans: Not really. But some old leaves can become yellow or brown. After maturation, they may take such color and fall. But the upper leaves cannot turn brown naturally.

Q: Can I still eat zucchini from a plant with brown leaves?

Ans: It’s generally safe to eat zucchini from a plant with brown leaves as long as the fruit is healthy and not affected by any diseases or pests. However, it’s always recommended to wash the zucchini thoroughly before consuming it.

Final Thoughts

So, let me end here. I have tried to focus on the problems that may cause the initiation of brown leaves in your plants. Among them, pest and disease attacks, sunlight issues, watering problems and nutrient deficiency are the most common problems of all zucchini plants.

So, match your problem with my problems and if you want, you can pick up the solutions that I applied to my plant. Like my other friends, it may also help you to save your plant from dying and discoloration. 

Happy Gardening.

James Rivenburg
James Rivenburg
James Rivenburg

James Rivenburg is the founder of plantandpest.com, a passionate gardener with valuable experience and knowledge gained through trial and error. The website has a large community of followers who trust his tips and techniques and have succeeded with his advice. He is always Committed to helping others create a beautiful and healthy garden.

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