What Causes Blossom Drop in Tomatoes?

I recently received an email from One Hundred Dollars a Month reader, Kathy in Ohio.  She wrote,

Hi Mavis! Happy Wednesday to you!  Have you ever discussed blossom drop in tomatoes? It’s when the blossoms bloom then drop off tomato plants, with no fruit setting. Someone recently came to me asking about it, and luckily enough, after years of caring for acres of tomatoes when my step father was alive on the farm, I was able to help her.
I think your readers would like to know about this. After all, it has been hot and humid around most of the country lately and that can be a factor when dealing with blossom drop.

It can also affect other fruit bearing veggie plants like peppers, green beans, cucumbers, pumpkins and other squash, melons and eggplant
By the way, I’m in NE Ohio,  where it’s been near 90 or above, with super high humidity.

Have an excellent day!

Excellent suggestion, Kathy.  Thanks!

Blossom drop can be maddening.  The worst part of blossom drop is that several things can cause it.  It is an indication that the plant is under some level of stress, so you may have to trouble shoot a bit what could be causing it in your specific situation.  First off, blossom drop is when the flowers {that should eventually become tomatoes} wither up and fall off–which means no tomatoes.  Whah!

Typically, blossom drop occurs when temperatures spike very quickly or drop quickly.  Drastic changes in temperature really stress tomatoes out.  As Kathy mentioned, humidity can also do a number on potato plants.  If you live in a low humidity area, it’s an easy fix, you can try wetting the foliage a bit during the day to get a bit of humidity into the air around the plant.  If you live in a high humidity area, it’s pretty darn hard to control.

If the weather isn’t the problem, it may be a pollination issue.  If you don’t have bees buzzing around your garden, you may not have great pollination.  Without pollination, no tomatoes, plain and simple.

Lack of water or nitrogen in the soil can also stress out a tomato plant.  During the hottest months, it’s really best to give a deep water {like flood irrigation} once a week, rather than a daily surface sprinkle.  The water really needs to reach the roots, and if given the change, tomatoes like to lay some deep roots.  If you suspect your soil might not be very nutrient rich, try a quality organic nitrogen based fertilizer.  Follow the instructions on the fertilizer for application.

Inspect your plants regularly for insects or disease.  Again, an infestation or disease will stress out your plant, causing it drop flowers.

Finally, and this is probably the best case scenario, it can happen when you have a really heavy crop.

Yep, even too much of a good thing is not a good thing.  The good news is that after you harvest some of the tomatoes, it should resolve itself.  The plant only has so much nutrients to go around, so if there is an over-abundance of fruit, it will drop some of the flowers to concentrate on growing the rest of the fruit.

Once you know what is causing your blossom drop, you can easily address the issue {except for controlling the weather, I haven’t figured out how to do that yet :)}.

Thanks again for the suggestion, Kathy!  I can’t believe I haven’t thought to address the topic before.

~Mavis