It’s midsummer, and I have a bunch of healthy-looking green tomato plants without any fruit. Shortly after I planted the starts, the flowers developed, and promptly fell off, taking a bit of the stem-end with them. The spot where I’ve planted them is in full sun, they have good soil, and they get watered as they should. Any idea what might be going wrong?
The problem which most closely resembles your description of what is happening with your tomato plants (flowers falling off shortly after planting, and taking a bit of the stem as they drop) is called ‘blossom drop.’ According to D. G. Hessayon’s Vegetable Expert (PBI, 1990), blossom drop occurs when pollination fails to take place, and there is dryness at the roots or in the air. There is no treatment for this malady, but watering regularly, spraying flowers in the morning, and tapping the plants to aid pollination are preventive measures. Attracting beneficial insects to your garden will also help with pollination.
Here are links to more information that may be useful to you:
- University of California Integrated Pest Management pages on tomato problems and pollination
- Washington State University – Spokane County Extension: Why Blossoms Fail. Note also that WSU Extension in Spokane County says cool night temperatures may cause blossom drop.
- University of Illinois Extension:”Tomato blossom drop is very common with high summer temperatures. Tomatoes will drop blossoms when daytime temperatures in the summer are above 90 degrees F. Blossoms will also drop earlier in the growing season when night temperatures drop below 55 degrees F.”
- This article from the spruce provides a lot of detail about the problem and how to prevent it:
Blossom drop can be attributed to several causes, most often related to either temperature and/or stress.- Temperature too high or too low
- Lack of pollination
- Nitrogen: too much or too little
- Humidity too high or low humidity
- Lack of water
- Stress from insect damage or disease
- Too heavy fruit set
This article recommends planting varieties known to do well in your climate, ensuring pollination, avoiding over-fertilizing, taking note of humidity levels, and watering deeply once a week in dry weather.