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Why Are My Garden Plants Turning Yellow?

Image by, courtesy of Lo

Planting a garden is a rewarding, educational experience. After all your hard work planning, planting and cultivating your garden, it is disappointing when your plants become unhealthy. Yellowing leaves is a common problem, and there are many reasons that plants in your garden turn yellow.


A lack of adequate amounts of nitrogen in garden soil is a common problem that may result in plants and leaves turning yellow or pale green. Nitrogen deficiency in soil is often mistaken as a lack of moisture, which can lead to over-watering. Test the soil using a pre-packaged kit to determine whether you must add nitrogen.


Some plants, such as parsley, tomatoes and cucumbers, require at least six hours of full sunlight per day to thrive. Yellowing leaves may be a sign that your plants are not receiving enough sun. Be sure to plan your garden so your vegetable and herb plants receive sufficient sunlight.


Over-watering is a common reason for plants turning yellow. Proper drainage in your garden area is key, as well as thoroughly reading seed package and seedling directions so you know how much water your plants require. If over-watering is the problem, simply stop watering for a few days. Push your finger into the soil to a depth of 2 to 3 inches to check the moisture level. If the soil is muddy and sticks to your fingers, it is far too damp.


Plant fungus is another common problem that can cause leaves to yellow and wither. Since there are many kinds of plant fungus and just as many cures, contact your local university cooperative extension office to help determine what kind of fungus is growing on your plants. The agent also will tell you what products to use to cure the fungus.


Pests also can cause your plants to yellow. Aphids, worms, caterpillars, flies, mites and others can make plants their home and literally suck the life out of them. Organic and chemical treatments are readily available to help rid your garden of unwanted pests.

Treated Water

City water may be treated for human health and safety. However, that does not mean it is best for your plants. If you are watering your garden with chlorinated city water, this may cause your plants to turn yellow. Using a rain barrel can be a great solution. Place an empty 55-gallon drum outdoors to collect rainwater and use it to water your plants.

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