You don't have to do anything to "save" the plant. If you water more consistently you will take care of the primary cause of the BER (Blossom End Rot).

Are your plants in containers or in the ground? How often do you water and how much?

As a general rule, tomatoes need an inch of water every week. An inch of rain is exactly that, water that is one inch deep. One inch of rainfall equals 4.7 gallons of water per square yard. Cool weather or soil with lots of clay needs will be less, hot weather or sandy soil will need more.

Dig down with your finger about 4", is the growing medium wet, dry, or just right? If it is wet, don't water, if dry then water. If it is just right, check again the next day. Water deeply once or twice a week. Watering daily encourages shallow roots which means the plant is affected more by variations in soil moisture/temperature.

Mulching heavily (to a depth of 6 - 8 inches) with compost, straw, hay, rotted leaves, grass clippings, even shredded paper or sheets of paper or cardboard helps maintain a consistent moisture level.

You can use tomatoes with BER by just cutting it out. Or if you wish you can just dispose of them, it isn't a disease and most plants that have it, will do so early in the season will grow out of the calcium transportation issue and have BER free fruits later in the season.

Betsy

Here is a link that might be useful: FAQ page on Blossom End Rot

Agree with Betsy. The plant is fine. It doesn't need "saving" from anything. It isn't like it is infected with a disease.

It is the fruit that are the problem right now. So you pick and pitch the fruit with BER and fix the watering issue and the BER goes away.

If the excess N in the soil is also contributing to the problem, and I suspect it is given the "huge plant", then the plant will adjust in time assuming you don't feed it more nitrogen.

Dave

Thanks guys. The plant was actually given no fertilizer. That's why I was so suprised it is getting so much bigger. But then again, I've never grown that variety. He does tend to water every day in small amounts. Never thought of this. I will adjust the watering. Would super phosphate help at this point?

Thanks!

Yeah the composted manure counts as fertilizer. :) That particular plant may be planted in a pocket of it.

Manure also supplies plenty of phosphorous so more isn't needed.

Dave

Ohhhh. Yeah, I guess manure would be a fertilizer even though it's composted. :). It's got to be the watering then. I'll pop off the bad tomatoes and adjust the watering. Thanks for the help!

Thanks for the great info guys! Just noticed one of my Roma plants has almost solid BER. Is on the same watering/fertilizing schedule as everyone else and they're all fine so I'm a little puzzled but will toss the affected fruit & wait for it to grow out of it.