I have a small inner city garden plot with 6 indeterminate tomato plants (each a different variety) and two bell pepper plants. Everything has grown vigorously. The tomatoes have plenty of fruit, but they seem to stop growing after a point and don't get bigger or ripen. The pepper plants are tall and strong but aren't making any fruit at all. All were planted from containers in late May.
Why Won’t My Tomatoes Redden?
Certified GKH Gardening Expert
When temperatures rise above 90 F and do not drop into the 70's at night, many varieties of tomatoes will slow down and even stop the ripening process. Extra watering can help to bring down the air temp around the tomatoes, but really, what you need are some cooler nights. The heat will also make it more difficult for plants (including pepper) to produce fruit. Once the temps begin to drop a bit, the plants should begin producing and ripening just fine.