I'm not sure, but I believe it's not really high temps that matter, but low temps. The plant has to see temps lower than the mid-70s SOMETIME to set fruit. If it gets over 100F in the daytime, but drops into the 60s at night, I think you're good to go. But in South Carolina, right now, you probably are not good to go.

As to what you can do about that, the standard southern gardening strategy is to plant out as early as possible (being careful about frost) so that its sets a load of fruit before it gets really hot. Then everything ripens while it is hot. As to turning down the temperature, there is nothing you can do.

Overnitrogenated soil would encourage beautiful foliage, but suppress flowers. Sounds like you have plenty of flowers, though.

I have been checking the weather in SC/NC border not too far from Florence. It has been consistently in 76 to 98F range, and often the highs reaching triple digits The reason I am doing this is because I might move to the area for the next season.

At those temperatures most tomato varieties won't set fruits. If you had planted out in March then the plants could set fruits before the high heat arrived. JMO

Sey

Ok, thanks for all the advice. I didn't plant early (late May), but bought somewhat mature plants..maybe 12-15" tall. I'll try to keep a close eye on a safe and earlier planting time next year.

Also, is there a particular type of tomato that's tried and true for this area? I just want to grow them for sandwiches and things.

I set my store bought plants out on about 15 March. I believe I could have easily avoided any frost issues and planted out 1 March. I have minimal experience. The results are in the photo. The peak in ripe tomatoes was first 20 days of June. After that heat affects pollination and size of the fruit. Big Beef should meet your expectations.

Here is a link showing plant dates by zone. http://www.clemson.edu/extension/hgic/plants/vegetables/gardening/hgic1256.html

At the bottom of table 1, there is a link to weather statistics.

Here are some photos from my journal to show harvest timeline on the coast.

7 May First Blush

15 May harvest. Should be encouraging. Shows what is capable in the zone.

21 May

24 May - there are Big Beefs in this one.

30 May