Is it true that most tomatoes will not bloom and set new tomatoes if the temp is 90 degrees or higher?

This has been a crazy summer for growing things. With high temps like we've had this year, I've had the best luck with tomatoes by finding a place that plant don't get direct sun until late morning or after. Example...this year my plants with full sun morning and PM are not producing as well as the ones getting 1/2 day of direct sun.

Three important things I've learned about raising great tomatoes:

1-Only fertilize them when you plant and again around the 4th of july (yep..only two times) More than two times will cause the plants to grow an incredible amounts of foliage. Plants look great but few tomatoes sent on until you give up on them (late summer or fall)

2-Trim plants weekly. Use cages and trim plants of stems and leaves that obviously aren't doing anything but sucking energy from the plant to create leaves which can rapidly turn your tomato garden into a jungle (many of you know what I mean)

3-Water frequently. Some people will tell you only to water when dry. If you do this and have a rain on almost finished tomatoes, the extra water will cause your tomatoes to expand an break the skin causing a significant crack. Ugly...and a great opportunity for bugs and birds to enjoy the stuff you were waiting for. Also, its really heartbreaking since you've watch these things grow for weeks. I've found it really important to water frequently when it is extremely hot. If you can avoid getting water on the plant, water at night. If you use a sprinkler, water before 9:00AM. A little water goes a long ways but keeping the higher underground roots on your plants damp will help and reduce plant stress and susceptibility to disease

Good Luck...hope this helps and you start packing them on.

In southern Oregon the temperatures daily hover around 100 f. One day a couple of degrees above 100, the next day a couple of degrees below 100. Our Tomato's grow fine and produce lots of tomato's in the hot weather.

When the temperatures get around 100 f. they show signs of wilt unless you water them. If you put water on them during the hot weather, they will grow a couple of inches in one day and produce plenty of tomato's. If you don't water to prevent the afternoon wilt, they won't do much. Water is essential during hot weather.

Mine were doing good until mid July, then it got hotter with over 100 degree days. I think tomatoes like some shade. The ones I have in partial shade look much better than the ones in the open sun.

Yes. It's the night time temperature that's important; if it's below 55F or above 72F, the tomato will not set fruit. Things may improve when the weather cools a bit.

Tomato production goes down when the weather is over 90.

My do and it hits over 100 a lot. Just keep them watered.