Sloat Garden Centers logo

Tomato issues

Home | Pest Problems | Tomato issues

Question

My tomato plants (2) were growing like mad and had many blooms. I was out of town overnight and when I returned the stems were starting to look slimy, then they quickly died, turning black. Can you tell me why?
Dolores
Pacifica

Answer

I am sorry to hear about your tomatoes. Crop failure always hurts when it hits established presumably healthy, vigorous plants. I think that you were struck by either Late Blight of Tomato or Bacterial Blight. The sliminess suggests a Bacteria and this is a disease that can ravage a plant very rapidly. The spores are airborne or carried in the stomachs of beetles such as the Diabroitica or Cucumber Beetle (the green "ladybugs"). The disease is likely to occur if we have warm or hot days and mild nights suddenly interrupted by much cooler, damp weather. Overhead watering will also stimulate an outbreak. I hope that you have removed the plants so that spores will not over winter in that spot. It is advisable to change the location of your tomatoes next year. To control the disease and reduce its spread, EB Stone Copper spray is recommended. I hope this helps. Please feel free to visit any of our store locations to get more specific instructions on how to use the Copper Spray, or just get more instructions for this year.

Share this post

More From Ask the Garden Guru

Newsletter Sign Up

"*" indicates required fields

This field is for validation purposes and should be left unchanged.
Copyright ©2026 Sloat Garden Center