So, you have a bumper crop of tomatoes coming on and you are looking forward to tasting that first ripe tomato. What a disappointment when you find that many of the ripe and almost ripe tomatoes look like they are rotting on the bottom!
What is blossom end rot?
It is a nonparasitic disease in which circular brown or black patches form at the blossom end of the fruit.
What causes it?
Blossom end rot can occur after the rapidly growing plants endure a prolonged dry spell or after a unusual heavy rainfall. This means that during any spring or summer, they can be susceptible. It is also caused by a heavy application of nitrogen. Remember, tomatoes do not need a whole lot of nitrogen. But, there is also an underlying cause no matter if the above mentioned have taken place. Calcium deficiency.
Blossom end rot can ruin a lot of your tomatoes, so preventing it from happening or treating it quickly can save you a lot of trouble.
Thankfully, prevention and treating are quite simple! Let's talk about prevention.
Since we know that a calcium deficiency is the root cause, what do we usually have on hand that contains calcium? Eggs! Yes! Crushed eggs put in the hole where you are transplanting will help prevent blossom end rot.
Also, do not over water or under water your plants. Another possibility that you might have to consider is your phosphorus level. If it is too low, then you might have a depletion of calcium as well. That is why it is very important to do a soil test(yes, anyone can do it). You can watch my youtube video from last year on doing your own soil testing below.
Lime and bone meal will also supply your soil with calcium, but you must plan ahead as it will take a few weeks for it to work in the soil. I do not recommend lime if your soil is already alkaline(higher pH) as that will make it even more alkaline.
I have sandy soil, so I have to keep up with soil testing! I found that phosphorous was slightly deficient in some areas, and of course, it was slightly acidic. By adding lime to my whole garden, and then adding compost, which contained eggshells, to my tomato transplants, I did not have a problem with blossom end rot last year.
But, one year I did.
I quickly discovered what it was and ordered Enz-Rot(tm) Blossom End Rot Concentrate Spray Plant Care By Gardens Alive 2840-12. This is simply calcium chloride. I drenched my tomato plants with this, and when my second round of tomatoes came in, there were very few tomatoes affected.
I encourage you to try these tried and true preventative measures and your tomatoes will look beautiful this year!