Stopping Tomato Blossom Drop

The blossoms of happy tomato plants are strong-stemmed and vigorous.

“I have a very healthy tomato plant that will only produce a few tomatoes.  The blossoms fall of rather than setting.  Thank you.” Question from Ron from Cashmere, Washington.

Answer: There are loads of reasons a seemingly healthy tomato might drop blossoms and most of them are either environmental or physiological. Here are some likely possibilities considering your Pacific Northwest location and the fact that your plant appears to be otherwise healthy.

  1. Fertilizer regime: Excess nitrogen in the soil will result in glorious looking plants that bear little to no fruit. Choosing a fertilizer developed to encourage tomato fruiting is essential for good crops.
  2. Insufficient Light: Tomatoes need at least 6 hours of full sun a day for good flower and fruit set. More is better.
  3. Pests and diseases: Gray mold (Botrytis) can cause blossom drop as can some pests, but you would see the insects and fuzzy mold on the blossoms.
  4. Temperature extremes: When day and night temperatures become too hot (daytime above 85 to 90 degrees F with little decrease at night) they can drop flowers. Likewise, when day and night temperatures become too cool (below 60 degrees F) they can drop flowers from stress. Choosing varieties resilient to temperature extremes can help.
  5. Strong, drying winds: Wind stress will on occasion cause blossom drop.
  6. Weather extremes: Weather that is consistently too dry or too wet can yield the same results.

Do any of these culprits seem like possibilities in your garden?

Happy Gardening! Jessie