Indoor tomatoes won’t ripen
I have three different mini tomatoes growing in my south window. (South is the only exposure.) I have lots of flowers, and quite a few tomatoes, cherry and pear. The oldest are several weeks old. They are still firm and have faded to a light green, but stop there. I am aware that if it is too hot they won't ripen, but on the hottest days the apartment was air-conditioned to 72 degrees. If the sun was too much for them, would it have stopped the ripening process forever? Is there a way to kick-start the process while they are still on the vine?(I tried putting a plastic bag with a banana slice in it around a few of them but it doesn't seem to have any effect.) Or do I just have to learn to make fried green (cherry) tomatoes?
Certified GKH Gardening Expert
This, actually, sounds like a symptom of two causes. The is common with a lack of light, actually. It will prevent the tomatoes from ripening completely. Windows will filter out some of the important light, such as UV, which will be necessary for tomatoes to ripen.
Fortunately, there are many horticulture grade lights on the market (I tend to recommend LED as long as it is equipped full spectrum with UV and IR diodes) that will help the plant grow to its potential. This will be necessary if you want more than just a handful of tomatoes over the span of the plants life.
The second issue to address is nutrients. This can be a common symptom of a nutrient imbalance. This will be too much nitrogen, and not enough phosphorus and potassium.
Fortunately, this can be solved with nutrients made for tomatoes, or just a fruiting fertilizer with low nitrogen, but high phosphorus and potassium.
This article will help:https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-indoor-tomatoes.htm