My tomato flowers are dying

by Robyn
(Oberon, NSW, Australia)

I have never watched my tomatoes so much as this year. I have put my plant in a pot. Even put it in the sun room and it has grown beautifully although thin and tall. I have noticed it flowers, but then the flowers are dying off. Is this normal before the fruit forms or is something wrong? My plant has 3 sets of flowers, but they have discoloured and look like they are dying but no sign of fruit is showing yet.

Tomato Dirt responds ...
That your plants are thin and tall tells us that perhaps they are not getting enough sun. Often plants are leggy when they do not get enough light. Their branches are "reaching" for sun.

Blossoms die after they are fertilized and fruit forms. You will see a tiny little fruit in the center where the flower used to be. However, sometimes tomato plants experience blossom drop, even indoors. Flowers fall before they are fertilized, and no fruit forms. There are at least 5 reasons conditions that can lead to blossom drop in tomatoes.

1. Extreme temperatures. Cool nights (consistently below 55ºF) or hot spells (days consistently about 90ºF and nights consistently above 75ºF) force the tomato plant to abandon fruit production and focus merely on surviving. Tomatoes’ optimum daytime temperature range for setting fruit is between 70º-85ºF.
   
2. Poor pollination. When temperatures are too hot or too cold, insects aren’t active in the garden. Not as many blossoms are pollinated. Along the same lines, without proper humidity (40-70%), pollen has difficulty releasing or sticking.
   
3. Stress. Tomatoes have deep root systems. Shallow watering develops shallow root systems, which can weaken tomato plants.
   
4. Improper fertilizing. Tomatoes are heavy feeders. Nitrogen (represented proportionally by the first number in a fertilizer’s three-number series) encourages leaf growth. Too much nitrogen-rich fertilizer, without accompanying phosphorus and potassium, can mean plants develop more leaves than fruit.
   
5. Too many blossoms. When a healthy tomato plant has many blossoms, they compete for food. Some won’t survive.