The temperatures heated up, the tomatoes started performing. Tomato plants don’t mind hot weather and will keep their composure even when more heat sensitive vegetables wilt pitifully, but they will not set fruit if the temperatures are above 85 to 90 degrees during the day or 75 at night. Considering the climate we live in, that’s most of the summer. It also explains why the extra leafy vines suddenly decide to become fruitful mid-September, when their fruit doesn’t really have enough time left to ripen.
The reason for this is that at higher temperatures the pollen becomes non-viable, or too dry to stick to the pistil.
How to remedy the situation? Unless you are growing tomatoes in a temperature controlled greenhouse there is not much you can do about it, other than root for accommodating weather.
Here are a few varieties that perform better than average in hot weather, but if temperatures are consistently above ninety degrees they will not set fruit either: SuperSweet100, grape tomatoes, Florida 91, Sunmaster, Heat Wave, Sunbeam, well, you get the idea, if heat or sun is part of the name, they’re it.
Temperatures behaved themselves so far, and therefore there are tiny green tomatoes to show. Naturally I mislabeled the varieties, and planted Brandywine, which needs more room, in the tighter spot. It hasn’t bloomed yet, but developed spectacular foliage.
If the soil is too rich or has too much nitrogen the plants will grow leafy to the detriment of setting fruit. Tomatoes like soils with a pH between 5.5 and 7 and need about three gallons of water per plant per week to be at their best, but avoid overdoing it during the harvest season to prevent the fruit from becoming watery.
If you have the room, tomatoes will be quite happy to sprawl on the ground, but they yield more trained on vertical supports. Pruning will encourage larger fruit, though not necessarily more of it. Remove all the suckers (the small shoots that develop at the nodes between the stem and a main branch. Keep the number of main branches around four. When the tomato reaches the desired height, pinch the top to stop it from growing, otherwise the indeterminate varieties will grow indefinitely. The determinate varieties hardly require pruning.
Grow marigolds around tomato plants to keep pest insects at bay and basil to improve the flavor of their fruit.

Author's Bio: 

Main Areas: Garden Writing; Sustainable Gardening; Homegrown Harvest
Published Books: “Terra Two”; “Generations”; "The Plant - A Steampunk Story"; "Letters to Lelia"; "Fair"; "Door Number Eight" ; "A Year and A Day"
Career Focus: Author; Consummate Gardener;
Affiliation: All Year Garden; The Weekly Gardener; Francis Rosenfeld's Blog

I started blogging in 2010, to share the joy of growing all things green and the beauty of the garden through the seasons. Two garden blogs were born: and, a periodical that followed it one year later. I wanted to assemble an informal compendium of the things I learned from my grandfather, wonderful books, educational websites, and my own experience, in the hope that other people might use it in their own gardening practice.