I currently live in New York. I'm interested in having a Dwarf Cavendish as a indoor houseplant, in my apartment. Will it survive/thrive? I can definitely provide sufficient humidity. I know having a house with a patio is much better but I don't have that.
I have a few concerns, each of which may not be huge things, but together they can take a toll on your plant's health.
- Room: Do you have enough room for it? These are big plants when mature, and even if it isn't touching anything, if the leaves are constantly getting brushed against, by people walking past, etc, that will hurt your plant. It should generally be left undisturbed.
- Household dust: Dust, even if it looks like a thin layer, can be very detrimental to the plant's health. It cuts more light than you'd think, and clogs/blocks stomata. You will need to wash it off. A room-temperature, thorough shower is highly beneficial once a month, if practical.
- Water quality: If you have chlorinated water, don't water with it. Even softened well water is hard on bananas. You can kill the plant slowly that way. If you can use rain water or distilled water, that would be great.
- Vents: If you have a central air system, do not let air movement from any outlet blow directly at the plant. Summer AC and winter heat are both extremely drying, and you can easily burn the leaves with either, even if you have a humidifier going on. Keep it away from any air outlets, or any drafty doors/windows. These plants like consistency.
- Propane/natural gas: This can kill the plant, and even small quantities will be damaging. If you have a gas oven/range, gas fireplace/heater, etc, that can easily be an issue.
I've seen some very healthy banana plants grown as permanent houseplants, and I think if you stay consistent and take care of all the plant's needs, it will be very happy for you. Might be a bit until it flowers, though.
Musser's given an excellent answer, but there's a few other factors you should consider for your big potted plant: Miracle gro comes in a variety of different NPK formulations. You might want to check online for what formulation your type of banana, or bananas in general favor. Also, premixed fertilizers are usually sold without Calcium and Magnesium salts as they tend to make other nutrients precipitate. IIRC New York City water has plenty of calcium, but consider occasionally adding a tablespoon of Epsom salts (MgSO4) per gallon to your watering mix. Chlorophyll and Rubisco both require Mg++ to function properly. Happy green chlorophyll is required to harvest energy from light, and Rubisco is required to convert CO2 from the air into the sugars from which the plant makes everything else it needs.