I will not be keeping my windows open and plan to not heat see below. My greenhouse is made of glass and wood all of which I pulled out of contraction dumpsters. I have enough glass for a 500 square foot surface with 4 layers of glass. This will give me a 37 foot by 15 foot tall lean-to green house at 8 feet wide against the south side of my house . The outside layer of glass is hermetically sealed. The 3 inside glazes breath some. The inside is kept humid. When the surface get cold the vapor in the air condenses and give the heat of fusion to the inside air. This keeps the inside warm. When the out side gets below freezing the vapor must condense first (520 cal./gram H2O) then must release another 80 cal. per gram h2o to the in side air thus keeping it warm inside. The outer glass surface is locked at 32 F until all the moisture on its surface is ice. The next layer of glass must go through the same, then the third layer must succumb to this solid ice frosty state, The frosty state of moisture on the glass will greatly decrease the amount of heat that can slip through. This alone probable guaranties my safety to 10 F for many days in a row. I heat the growing medium with the south basement wall. The R value of it is about R-4, While the other 3 walls are R-150 Minimum an loose near 0 heat. I heat the basement to about 75 F. There are no ducts to heat any where else in the house. With living area walls at R-40 they loose heat slowly enough to stay warm with the heat in the basement just bleeding up. The warm basement wall keeps the greenhouse soil at 60 F min. My annual natural gas heating bill is under $200 . If the temperatures drop below 0 F I will have to place out buckets of warm water to supply the needed humidity to power the gasses phase change heating system. Steve

Now that I have learned to grow citrus with no problems I have 3 Poncirus trifoliata of grafting size and 4 sweetlee tangerine trees of vigor that will be graft-able next spring. That's 7 root-stocks that I can graft my twigs from the grafted tree I can purchase. My purchased tree will grow faster by waiting a year and will out grow anything I bought a year earlier. My decision is to not buy a grafted tree and to grow what I have. If it fruits, great If they don't. Well we'll see My from seed Nagami kumquat for grafting to poncirus trifoliata Seed grown Meiwa kumquat tree. The tree fruit I am interested in. To be grafted on to the poncirus trifoliata moots through the Nagami inter-stock. May also go directly to my sweetlee tangerine tree root-stock, Seed grown sweetlee tangerine tree for root-stock #1 Seed grown sweetlee tangerine tree for root-stock #2 Seed grown sweetlee tangerine tree for root-stock #3 Seed grown sweetlee tangerine tree for root-stock #4 Seed grown poncirus trifoliata to be grafted on Is posted above . Its in a blue 55 gallon half drum. This completes what I have done and what I have. If I think of anything I'll add on to this thread Steve This post was edited by poncirusguy on Tue, Nov 5, 13 at 18:29

I am NOT an expert. But you'll need lots of light, plus good heat and humidity -- and air movement. I've kept potted citrus indoors from time to time, not very successfully. Mine eventually come down with mealybugs. Good luck!

I'm not sure if my experience will help, but I'll try. I have dwarf cavendish outdoors in a shaded location and they can stand shade in lieu of full sun, but they grow slower, and pup less frequently. I know you read that bananas feed a lot, and they do, but not as much as you plan. When I moved in they were neglected for a year (bank foreclosure) and were fruiting so they were neglected on watering and food. Now that they get irrigated at least weekly whether by rain or hose and are fed more regularly they are still slower to pup and fruit than other cultivars I have that get the same attention but more sunlight. So my advice would be to mulch them, don't let them dry out, feed "regularly" but vary the food source. Bananas also like clean wood ash, but don't use ash from paper or cardboard. As far as pups go, once the korm grows and spreads I think you'll have to find bigger buckets too. I also think you'll do better with multiple pots of bananas rather than one. I find that on occasion my pups will outperform the parent in fruit growth and pup production just by being in a different location. I hace some 8 or 9 different bananas and find very different growth habits based mostly on light.