By Nikki Phipps
(Author of The Bulb-o-licious Garden)
Are your tomato leaves curling? Tomato plant leaf curl can leave gardeners feeling frustrated and uncertain. However, learning to recognize the sign and causes of curling tomato leaves can make it easier to both prevent and treat the problem.
Tomato Plant Leaf Curl Virus
Curling tomato leaves may be a sign of a viral infection. Normally this virus is transmitted through whiteflies or through infected transplants.
Though it can take up to three weeks before any symptoms develop, the most common indicator of the disease is the yellowing and upward curling of the leaves, which may also appear crumply. Plant growth soon becomes stunted and may even take on a bush-like growth habit. Flowers usually will not develop and those that do simply drop off. In addition, fruit production will be significantly reduced.
Other Reasons for Tomato Curling Leaves
Another cause of tomato plant leaf curling, also known as leaf roll, is attributed to physiologic conditions. While its exact cause may be unknown, it’s believed to be a sort of self-defense mechanism.
During excessively cool, moist conditions, leaves may roll upward and become leathery in an effort to repel this excessive moisture. This specific condition occurs around fruit setting time and is most commonly seen on staked and pruned plants.
Curling tomato leaves may also be triggered by just the opposite—uneven watering, high temperatures, and dry spells. Leaves will curl upward to conserve water but they do not take on the leathery-like appearance. Plum and paste varieties are most commonly affected.
Cure for Tomato Leaves Curling
Although physiologic effects for tomato leaf curl do not affect the overall growth or crop yields of plants, when the tomato leaf curling is due to a viral infection, removal of the infected plants is necessary.
You should also destroy these tomato plant leaf curl infected plants to prevent any further transmission to those nearby. The key to managing tomato leaf curl is through prevention. Plant only pest and disease-resistant varieties. Also, protect garden plants from possible whitefly infestations by adding floating row covers and keep the area free of weeds, which often attract these pests.