Advice for growing tomatoes indoors.
Has sun, fertilizer, water and pollination help but, although it starts to bud, it never flowers.
Certified GKH Gardening Expert
It will not receive enough sun indoors, even in a South facing window.
I keep a tomato plant or two indoors all year. They need several things indoors, if you intend to get fruit from them inside.
Light will be paramount. They need lots of it. at least 100 watts per plant is fine, but 200 per plant, or per 2'x2' area will be ideal. (I use a Ceramic Metal Halide of 315 watts, which lights a 4x4 area comfortably.)
Nutrients: Tomatoes are heavy feeders. VERY heavy feeders. They will take all of the nutrients that you throw at them. A good, organic, granular fertilizer will do wonders. Feed them once per month, or as needed.
Watering is pretty easy once they are growing fast. You will need to water deeply once per day once established, or water as the top two to four inches of soil dry out COMPLETELY.
Disease: Disease in not avoidable at all indoors. You will come face to face with it at some point. It is best to have pesticides of your choosing, fungicides, and extra soil on hand in case you need to clear out for disease and start over.
Flower drop can mean many things. It can be that it is being overwatered, which can be especially true if it is growing slowly from lack of light. Sometimes it can happen from lack of temperatures fluctuating between day and night drastically. This will signal the plant into vegetative growth. They need a temperature difference of more than 10 degrees or so between day and night in order to fruit properly. Having a warm light on them will cause this temperature difference when you turn them off at night. Lack of humidity can also cause bloom drop. Air conditioners are notorious for removing humidity, so spraying, or humidification may be necessary. Finally, too much nitrogen can cause bloom drop. Offset with potassium and phosphorus to correct.
This article will offer information on what tomatoes require in order to be healthy: https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-tomatoes-guide.htm