My tomatoes rot on bottom part

by Bob Fuentes
(Lincoln, CA)

Q. My tomatoes plants are in pots, but once they begin to ripen, they start to rot on the bottom side. I have them on a sprinkler system to water 2 times in the morning for approximately 8 minutes a day. I planted them with Miracle-Gro for Vegetables. It has been very hot - 100 degrees. What am I doing wrong?

A. It sounds like your tomatoes have Blossom End Rot (BER), which is caused by a calcium imbalance. When plants are under stress, they have difficulty with calcium uptake, even if you water regularly. Tissues break down. That causes the rotted, leathery ends on your tomatoes.

Excessive heat is one stress factor that causes BER. It's likely that your current high temperatures may be stressing your plants, especially since they are in containers.

While you can't control the weather, you can help ease the stress on your plants by moving them out of direct sun during the heat of the day.

Keep up the regular watering. But remember, daily watering can leach nutrients from the container. Fertilize your tomatoes in pots every 10-14 days.

BER is often most prevalent during early to mid-season.

You can use these natural products specifically developed to treat, prevent, and slow blossom end rot in tomatoes: Enz-Rot Blossom End Rot (a concentrate that can make up to 8 gallons) and Tomato Rot-Stop (in a ready-to-use spray bottle.) Follow package directions for application.

You can learn more about Blossom End Rot here.

Good Luck and Happy Gardening!
Your friends at Tomato Dirt