The Tropical Fruit Forum

Hello!
I realize it's quite late to be looking for fruit trees, but this tree is for a dear friend that doesn't know any better. He's also impatient and inexperienced, so he needs something a little bigger than what you can find at online nurseries. He's willing to buy or I'll be willing to trade on his behalf. I've got a large collection of rare/interesting fig trees. 

See youtube.com/rossraddi for a little context on who I am. I know I don't really have much activity on this forum.

Other than Trifoliate, does anyone know of a hardy citrus variety that could withstand 0F? Maybe 5F if I protect it on very cold nights?
I was recently told about Yuzu and got excited as Trifoliate is not really usable in the kitchen. I'm not looking for the next navel orange, but a nice replacement for a lemon/lime that could survive here would be amazing.
Perhaps Sudachi?

Hello! I'm Ross and I just joined the forum! I'm looking for some solid advice on my citrus. I'm hoping I can learn from all of you.

A little background:

Due to space constrictions and my cold climate (Zone 6A/7B) I'm limited on the amount of citrus trees I can grow. Indoors I have a 3x3 grow room and that's it! So whatever fits in there is unfortunately all she wrote! Currently I have two mandarin trees that I picked up from StarkBros nursery last year. They haven't fruited yet and there's almost no information on the variety. I called the nursery and they don't even know if it's seedless... I'm thinking about adding 2 more citrus trees or what seems more likely is that I should start over with my citrus completely because the trees I bought are basically unknowns: https://www.starkbros.com/products/fruit-trees/citrus-trees/tangerine

My questions:

1. How many mature trees could I fit in that space? I'm thinking I could squeeze in 4, 10 gallon trees, but 2 or even 1 is probably more realistic. However.. I do  want to be sure that I'm maximizing my space.
2. What will my harvest be like per 10 gallon tree at maturity?
3. If I'm only looking to grow mandarins or oranges, will heat be an issue if I bring them indoors for the winter? I want to be sure the fruit is sweet.
4. Should I replace my current trees? If so, what varieties should I choose? I definitely want a successive harvest during the winter to early spring. I was thinking Cara Cara orange & Tango Mandarin would be good choices.
5. When do you move your citrus indoors? Historically I've been moving them indoors when temps consistently reach below 60 F & moving them outside when temps are consistently above 60 F.

I look forward to your responses!
Thank you,
-Ross