The Blooms on My Tomato Vines Are Dying

Extreme Temperatures

• Proper temperature plays a key role in helping tomato vines set fruit. Similar to other plants, tomatoes are sensitive to fluctuations in temperatures. The plants thrive in consistent temperatures between 70 and 90 degrees Fahrenheit. Although short-term exposure to temperature higher than 90 degrees or lower than 55 degrees does not cause any damage, exposing a tomato vine to temperatures lower than 55 degrees for four straight nights causes the blooms to die and fall off. Similarly, prolonged exposure to nighttime temperatures above 75 degrees also causes blossom drop.

Improper Irrigation

• Improper watering practices increase plant stress that in turn affects the blooms. Because a tomato is made up of 95 percent water, it fails to develop without adequate moisture. Tomato roots extend 3 to 5 feet deep in the soil, increasing the need for proper irrigation. Conversely, over-watering the tomato prevents its roots from absorbing oxygen and increases plant stress. To prevent blossoms falling due to improper irrigation practices, water the plant's root zone 3 to 5 feet under the soil. Increase irrigation during the summer and in prolonged periods of drought.

Pest Problems

• Tomato vines stressed by pest such as thrips and aphids occasionally lose their blooms. Aphids are tiny pests that suck juices from leaves with their piercing mouth parts. The damaging pests also exude honeydew, a black sticky substance that increases chances of sooty mold fungus. Thrips are vectors, or carriers of the disease that causes spotted wilt. Tomato vines damaged by one or both types of pests fail to keep their blooms intact.

Improper Nutrition

• Nitrogen is an essential nutrient associated with blossom drop. While lack of nitrogen causes the blooms to drop, excessive amounts are harmful for the tomato plant as well. Commercial fertilizers not specifically formulated for use on tomatoes tend to provide the plants too much nitrogen. Similarly, it is easy to over-fertilize your tomato plants with nitrogen, especially if you feed them every week. Use a fertilizer specifically formulated for tomatoes, and follow manufacturer's directions for dosage recommendations.