Tomato Blossoms

by Demi
(Athens, Greece)

Q. Our tomatoes didn't have much luck this year. Blossoms fall apart before they set fruit. I heard that when flowers bloom, we should cut back the water for a while, but I wonder ... should I cut back water when the tomato blossoms open up or before that, just they start to form and I know they are flowers? The timing confuses me.

Tomato Dirt responds ...
A. When a healthy tomato plant blossoms may drop, and no fruit develops, it's most often a result of plant stress or poor pollination.

What causes the stress to tomato blossoms

• 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.
  
• 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.
  
• Stress. Tomatoes have deep root systems. Shallow watering develops shallow root systems, which can weaken tomato plants.
  
• 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.
  
• Too many blossoms. When a healthy tomato plant has many blossoms, they compete for food. Some won’t survive
  

So you can see that reducing watering for your tomatoes simply creates more stress. More stress makes it harder for tomato blossoms to set fruit. Instead of reducing watering during any stage of blossom development, keep up a regular watering schedule.

You can encourage blossoms to set further by using a natural plant hormone such as Tomato Blossom Set Spray.

Find out lots of other information about tomato blossom drop.

Good luck and happy gardening!
Your friends at Tomato Dirt