Why are tomato plant leaves turning yellow and purple?

As a tomato plant owner, it can be disheartening to see yellow and purple leaves on your once thriving plant. There are several possible reasons for this occurrence, including:

1. Nutrient deficiencies

Tomato plants require a number of nutrients to grow and thrive. If the plant is not receiving enough of a certain nutrient, its leaves may begin to turn yellow or purple. Two common nutrient deficiencies that can cause this issue are:

Nitrogen: A lack of nitrogen can cause the lower leaves of the plant to turn yellow, while the upper leaves remain green. To remedy this, try adding a nitrogen-rich fertilizer to the soil.

Phosphorus: A phosphorus deficiency can also lead to yellow leaves, but in this case, they will be more brittle and may curl. Add a phosphorus-heavy fertilizer if you suspect this is the issue.

2. Disease or infection

Yellowing and purpling of tomato plant leaves can also be a sign of disease or infection. One common culprit is Tomato Spotted Wilt Virus, which is a virus transmitted by thrips. Other possibilities include:

Bacterial spot: This bacterial disease can cause small, dark spots to appear on the leaves before they turn yellow and fall off.

Fusarium wilt: A fungal disease that can cause yellowing, wilting, and eventual death of the plant.

If you suspect that your plant has a disease or infection, it is important to act quickly to prevent it from spreading to other parts of your garden. Remove any affected leaves or plants, and consider using an organic pesticide or fungicide to prevent further damage.

3. Environmental factors

Finally, yellow and purple leaves on tomato plants can also be caused by environmental factors. Some possibilities include:

Temperature: Tomatoes thrive in warm temperatures, but too much heat can cause the plants to become stressed and produce yellowing leaves. Similarly, exposure to cold temperatures can also cause damage.

Water: Overwatering or underwatering can both lead to yellowing leaves. Be sure to water your plants regularly, but do not allow them to become waterlogged.

Lack of sunlight: Tomato plants need plenty of sunshine to grow and produce fruit. If your plant is not getting enough sunlight, its leaves may begin to turn yellow or even purplish in color.

If you suspect that your plant's yellowing leaves are due to environmental factors, try adjusting the plant's location or watering schedule to see if this helps.

Conclusion

Yellowing and purpling of tomato plant leaves can be a frustrating problem for any gardener, but there are several possible solutions. By identifying the cause of the issue and taking appropriate action, you can help your tomato plants to once again thrive and produce delicious fruit.