Why are my tomato plants dropping their blossoms?

When the temperature outside is 92°F or hotter, the tomatoes will drop their flowers (blossoms) and will not set any fruit. This is called Tomato Blossom Drop and is normal for a tomato to do. Basically they self-abort their blossoms. Why? Because they want to survive. They will continue to produce new blossoms and once the temperatures is BELOW 92°F, they will start to set fruit from the blossoms.

What can we do to prevent blossom drop? Nothing. We really are at the hands of mother nature. The funny thing is once they do pollinate (tomatoes are self-pollinating and wind-pollinated and don’t need pollinators) and they produce baby fruit, they do fine when it’s hot-it’s just while they are trying to set fruit that the temperature is critical. There is also a low temperature where they will drop the blossoms, but we don’t have to worry about that here.

Last year we had 3 months of intense heat with everyday being 92°F or warmer and the blossom just couldn’t set fruit. Finally when the monsoons came mid-August (which is one month later than normal), and it cooled down, they were able to set their fruit. Luckily for us we had a long fall and were able to harvest before we got a freeze. So don’t despair, they will set fruit from their blossoms when the time is right. Hopefully the monsoons will come in July. So for now, just surrender and chill out (if you can).

Why we don’t have ripe tomatoes right now

So if you still have tomato plants after the curly top virus hit many of our plants, congratulations! I had 84 tomato plants and am down to 48. Thankfully I planted more this year or I wouldn’t be at the Farmer’s Market. I’ve gotten many questions on why we don’t have many ripe tomatoes now. Lots of green ones, but few ripe ones and normally we would have LOTS of ripe tomatoes now. The reason is we had an unusually hot July with day temperatures over 90°F almost every day and the blossoms dropped back then, failing to set fruit.  The number one reason for blossom drop is high temperatures over 90°F  during the time blossoms would normally set in July (the number two reason is cold temperatures under 55°F). Once the temperatures dropped below 90°F in August they resumed setting tomatoes again hence the green tomatoes we are seeing now. So basically we are a month behind but should start seeing most of the tomatoes ripening.  Ahh, the challenges of growing vegetables in the high deserts!