Tomatoes are often considered one of the simpler summer vegetables to grow. As long as they are provided with plenty of sun and water they usually thrive. Sometimes, they fail to blossom or the flowers begin dropping off before fruit is set, however. Without flowers, tomato plants can't produce the succulent red fruits. Troubleshooting the cause of failure to set blooms, then quickly fixing the problem, enables you to save the plant and achieve a good harvest.
Check temperatures throughout the day and night. Tomatoes tolerate no frost and will fail to bloom, drop flowers, or even might die if temperatures are too low. Plant tomatoes outside after all danger of frost has passed in your area, and cover plants with a row cover if temperatures are expected to drop unexpectedly later in the spring.
Verify that the tomato plant is receiving at least six hours of direct sunlight a day. Prune back any shrubs or trees that may be blocking the light or move tomatoes in containers throughout the day so they can follow the light if buildings are blocking it.
Avoid over-fertilizing with nitrogen-rich fertilizers. Excessive nitrogen leads to lush foliage and lack of flowers. Use fertilizers recommended for tomato plants at the times recommended on the label. Avoid fertilizing if the plant is stressed due to temperatures or drought.
Provide enough water for the plant, especially during times of drought, to prevent blossom-drop. Water once weekly providing 2 inches of water per plant, and more often during hot and dry periods. Apply a 2-inch layer of organic mulch around each plant to help preserve soil moisture.
Wait out periods of excessive heat, as many tomato plants quit blooming when temperatures soar over 90 degrees F. Provide enough water during this time and blooming will resume when the weather cools down.