Blossom end rot is a physiological condition of tomatoes, peppers and eggplant that can occur when there is not enough calcium in the fruit that is developing. This deficiency can occur from drought stress or too many fluctuations in the water supply when the fruit is developing that somehow makes the calcium unavailable to the fruit. On a tomato it looks like a brown patch on the bottom that continues to enlarge and eventually sink or rot.
It seems like early in the growing season, I have had this problem on many plants and have heard many others say they have a problem with it. Harry Ellmore of Ellmore’s Garden Center, Hamilton, Virginia, told me a remedy he uses and advises his customers to do also. He grows beautiful plants and has a reputation for quality.
He said to mix 1 Tablespoon of Epsom Salts (magnesium sulphate) in 1 gallon of water and water the tomato at the base of the plant with this mixture. You may not need the entire gallon. I expect it depends upon how big your plants are. Don’t pour over the plant, make sure you pour at the base. You can repeat this procedure twice a month. Hope you have a great tomato crop.
Photo from Ohio State University Extension website
http://ohioline.osu.edu/hyg-fact/3000/3117.html
thedailylily.com 
I love this. I will send to my brother right away. He just got 4 tomatoes off the plants he got from you. He said he forget just how good a fresh tomato could be coming right off the vine. I love that this has no chemicals. And, I know how unbelievable Mr. Elmore’s plants are. And, your plants are outstanding as well.
Thanks for sharing this vital info for gardeners. I sure want my tomato plants healthy for a good summer of eating.
I agree. I don’t want to lose even one tomato to this rot…the winter’s been too long with no fresh tomatoes!
Many readers will welcome the tips you have given to keep their tomatoes fat, juicy and rot-free. Maybe Mike McGrath of WTOP horticultural fame will
be find this tip most helpful, too. 🙂 We can all learn something new and expedient every day.
Thanks, Debi.
Thanks Debi, I’ll try this right away.
Debi,
To me, eating a fresh summer tomato is like a kid eating candy. It is one of my favorites! I don’t usually have a garden, but I did go out and buy myself six tomato plants this year, and my husband planted them, in our backyard. I will have to share this information with him. I so appreciate it, because I don’t want to loose a single tomato to this rot. By the way, how often should you fertilize or miracle grow a plant?
Needles if you are using miracle gro (which is a liquid fertilizer that is either ready to use pre-mixed or you mix in water) follow the directions on the package for vegetables/tomatoes. The same would be true if you are using a dry, granular fertilzer at the base of the plant. You are not supposed to use much fertilzer on them until the tomatoes start to develop/produce fruit. If you put too much/frequent fertilizer on a tomato plant before it develops fruits, you will have beautiful, lush green plants but little or no fruit.
Hope this helps and you have a bumper crop of tomatoes from those six plants!
Debie, thank you for the wonderful information about epsom salt. We have about 15 tomato plants this year. I appreciate every garden tip I can get. We love fresh veggies in the summer time. Thanks for the help.
Scented Marigold…Plant with: Everything!
Get these benefits: In dense clusters, this flower emits a substance that drives away harmful root-feeding nematodes. Near tomatoes, it can deter whiteflies.
That’s great advice about the whiteflies because I have seen them out on some plants already this year!
I’ve read basil is good to plant near tomatoes too because it’s supposed to keep flies and mosquitos away and helps improve the tomato flavor. Plus it sure makes good pesto.