Why Does My Geranium Have Yellow Leaves?

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Geraniums are among the most popular bedding plants, mostly due to their drought-tolerant nature and their lovely, bright, pom-pom like flowers. As wonderful as geraniums are, there may be times when you notice your geranium leaves turning yellow. What causes a geranium with yellow leaves and how can it be fixed?

Lack of Nutrients

Geraniums are not heavy feeders except when planted in poor soil. Apply a balanced slow-release fertilizer once a year at the beginning of the growing season in the spring. Yellowing leaves might hint to a deficiency in micronutrients, first and foremost magnesium which plays a crucial role in photosynthesis and is responsible for the green pigment of leaves. Other micronutrients that can cause yellowing leaves are sulfur, zinc, and iron deficiencies. Apply a balanced fertilizer that includes magnesium. If the foliage remains discolored, do a detailed soil test (available through your local extension Office) before adding a more concentrated form of magnesium.

Causes of Geraniums with Yellow Leaves

One of the most common causes of yellowing leaves is too much moisture or overwatering. Generally, on overwatered plants, the bottom portions of geraniums have yellow leaves. They may also develop pale looking water spots. If this is the case, you should immediately stop watering and allow the plants to dry out. Remember, geraniums are drought-tolerant plants and they do not like too much water. Water or air temperature that is too cool can also result in geranium yellow leaves. Geraniums are a warm weather plant and they do not deal with cool weather well. Cold snaps in the spring or extended cool weather, especially cool, wet weather, can cause geraniums with yellow leaves. In addition, when the geranium leaves become more yellow than green, a nutrient deficiency could be the cause. Geranium plants should be fertilized with a complete, water-soluble fertilizer (preferably one with micro-nutrients) at least every third watering or once monthly. Not only will fertilizer help prevent yellow leaves on geraniums, but it will also help the plant to grow bigger faster with more blooms. Occasionally, a geranium with yellow leaves is due to some type of disease. For instance, verticillium is a fungal infection that can cause stunted growth, wilting, and bright yellow leaves. What about geranium leaves with yellow edges? Geranium leaves with yellow edges or yellow tipped leaves on geraniums are usually attributed to a lack of water or dehydration. While geraniums are drought-tolerant, they do need some water. In these instances, you can feel the soil to determine just how dry the plants may be and water accordingly. It may also help to trim off the yellowing growth. As you can see, geraniums with yellow leaves typically need just a little TLC to help them recover. Give a geranium what it needs and you will not see your geraniums leaves turning yellow.

Geranium Problems, Pests and Diseases (And How to Fix Them)

FAQ

How do you fix yellow leaves on geraniums?

• Overwatering:

  Geraniums are drought-tolerant and dislike soggy soil, which can lead to root rot and yellowing. 

• Underwatering:

  While less common, prolonged dry spells can also cause yellowing, starting at the leaf edges and tips. 

• Nutrient Deficiency:

  Yellowing, especially if it starts at the bottom of the plant, can indicate a lack of essential nutrients like nitrogen, iron, or magnesium. 

• Pests and Diseases:

  Pests like spider mites or diseases like botrytis blight and rust can also cause yellowing. 

• Environmental Stress:

  Geraniums are warm-weather plants and can be stressed by cool, wet conditions or insufficient sunlight. 

What do overwatered geraniums look like?

You can tell that your geranium is suffering from waterlogging because the water drips out of the soil when you lift the pot. The leaves turn yellow and limp, and the flower stems and roots rot. In severe cases of waterlogging, the potting soil will start to stink.

Do yellow leaves on geraniums mean too much water?

Yellowing leaves on hardy geraniums are a sign of too much water. They are well adapted to dry conditions and only need watering when the top 1 inch of soil is dry to the touch. To prevent overwatering, make sure to plant in well-draining garden soil, or in containers with large drainage holes.

How often should you water geraniums?

• General Watering:

  Geraniums are relatively drought-tolerant once established, but regular watering is crucial for healthy growth. 

• Watering Frequency:

  • New Plants: Water newly planted geraniums more frequently, ensuring the soil is consistently moist, to encourage deeper root development. 

  • Established Plants: Once established, water deeply when the top inch of soil feels dry to the touch, usually once or twice a week. 

  • Container Plants: Plants in containers will need to be watered more frequently than those in the ground, as they dry out faster. 

  • Summer: During the warmer months, you may need to water more frequently, possibly every few days, depending on the weather. 

  • Winter: Reduce watering frequency during the cooler months as the plants’ water needs are lower. 

• How to Check Soil Moisture:

  • Finger Test: Insert your finger about 2-3cm into the soil. If it feels warm and dry, it’s time to water. 

  • Weight Check: If the pot feels noticeably light, it’s a good sign that the geraniums need water. 

• Best Time to Water:

  Water in the early morning to allow the foliage to dry before evening, which can help prevent fungal diseases. 

• Avoid Overwatering:

  Soggy soil can lead to root rot and fungal diseases, so ensure the soil has a chance to dry out between waterings. 

• Mulch:

  Applying a layer of mulch around the plants can help retain moisture and suppress weeds. 

Why do geraniums turn yellow?

Plant foliage appears yellow because it lacks sufficient chlorophyll — a condition called chlorosis. Nutrient deficiencies and disease are often to blame for this symptom. But chlorosis in geraniums can also be caused by cultural factors like improper watering, cool temperatures, or too little sun exposure.

How do you keep geranium leaves from turning yellow?

Here are a few things you can do to prevent your geranium leaves from turning yellow and practice good geranium care: – Water geraniums early in the day so that the leaves have time to dry before nightfall. – Remove any dead or dying leaves from the plant. – Cover plants with a frost cloth or bring them indoors if necessary.

What causes geranium leaves to wilt?

Blight will cause the lower part of the plant to discolor and wilt, whereas with Southern Bacterial Blight, the discoloration and wilting will always progress upward from the soil line. There are around 15 known viruses that can affect geraniums causing the leaves to yellow.

Why are my geranium leaves blotchy?

Blotches or spots on geranium leaves are generally indicative of a disease or pest issue. Fungal diseases, such as leaf spot or rust, can cause brown or black spots on the leaves. On the other hand, pests like aphids or spider mites can lead to small yellow spots on the leaves.

How do you know if geraniums are overwatered?

Signs of overwatered geraniums include yellow leaves often accompanied by drooping flower stalks. Underwatered geraniums typically present with yellow leaf margins that have a dry texture. These are just general guidelines, however, and the only guaranteed way to tell the difference is to examine the soil’s moisture level.

Why do geraniums rot?

Annual geraniums dislike wet feet and prolonged exposure to standing water can contribute to root rot. In other words, all the extra moisture in the soil smothers and subsequently rots plant roots. In time, the affected plant’s leaves turn yellow, die, and drop off.