• slide
  • slide
  • slide
  • slide
  • slide
  • slide
  • slide
  • slide

Blossom End Rot on Tomatoes

It's finally here!  Your first red tomato.  You reach in, twist it off the vine and have a look.  And there it is - a big black spot on the bottom of the tomato. 

The problem is blossom end rot.  It’s caused by a lack of calcium in the soil.  Now don't reach for the fertilizer, most soils have plenty of calcium.  If in doubt, have a soil test before spending money on something you may not need.  Root damage or moisture imbalances are usually the problem.  They prevent the plants from absorbing the calcium from the soil. 

The first flush of tomatoes is usually all that is affected.  The plants seem to adjust and correct the problem.   

Prevent the problem by keeping the soil evenly moist throughout the summer.  Proper watering and mulch can help.

Avoid root damage when staking and cultivating your garden. And, don’t use ammonium forms of nitrogen prior to or during fruit set.  

The good news.  It’s safe to eat the firm red portion of the tomato.

A bit more information:  Check the soil moisture in container-grown tomatoes daily.  Fluctuations in soil moisture are greater in containers than in-ground plantings.  That means a greater risk of blossom end rot.  Water thoroughly whenever the soil is slightly moist like the consistency of a damp sponge.  Most planters need to be watered thoroughly every day.  Some even twice a day.  Keep in mind the smaller the container and the higher the temperature the more often you need to water.

Upcoming Live Events
& Webinars


March 19, 2025
FREE WEBINAR:
Be a Waterwise Gardener
Register here


March 22, 23, 29, 30, 2025
REALTORS Home & Garden Show
West Allis, WI

March 26, 2025
FREE WEBINAR:
Succession Planting & Crop Rotation

Register here

March 27, 2025
FREE WEBINAR:
Rain Garden Q & A

Register here

April 2, 2025
FREE WEBINAR:
Container Gardens for Sun & Shade
Register here


April 10, 2025
FREE WEBINAR:
Reinvigorate Your Rain Garden
Register here


April 12, 2025
Plant a Colorful & Edible Spring Garden
Pasquesi Home & Gardens
Lake Bluff, IL

April 26, 2025
Organic Gardening Basics
Ebert's Greenhouse Village
Ixonia, WI

May 7, 2025
FREE WEBINAR:
Vertical Gardening
Register here


May 10, 2025
Ask the Plant Doctor Q&A
Ebert's Greenhouse Village
Ixonia, WI

May 11, 2025
Ask the Plant Doctor Q&A
Ebert's Greenhouse Village
Ixonia, WI

May 15, 2025
FREE WEBINAR:
7 Steps to Managing Water on Your Property

Register here

May 17, 2025
Ask the Plant Doctor Q&A
Ebert's Greenhouse Village
Ixonia, WI

May 18, 2025
Ask the Plant Doctor Q&A
Ebert's Greenhouse Village
Ixonia, WI

June 4, 2025
FREE WEBINAR:
Attracting Hummingbirds

Register here

June 8, 2025
Selecting the Right Hydrangea
for Your Landscape

Ebert's Greenhouse Village
Ixonia, WI​​​​​​​

WATCH ON-DEMAND WEBINARS

Learn More

Book an Appearance

Learn More

Enter to Win

Wild Valley Farms' Wool Pellets 
& Gardener's Bundle 

ENTER NOW