My potted trees require an area about 6ft by 4ft to 6ft by 6ft per tree depending on how much alley one needs between trees. In my opinion a high tunnel needs to be taller than a forced air greenhouse. A high tunnel uses natural ventilation for cooling. So the top half will be much hotter than the lower half. With trees about 7-8 ft tall, a height of 14-16 ft would be ideal. Twelve ft might work for a high tunnel and probably would work for a greenhouse. On a greenhouse the rule of thumb is one air exchange per minute to limit temperature rise to 15F above ambient. With evaporative cooling I can keep it as cool inside as out. But I'm in an area with much lower humidity than you. The Mango are going to add greatly to your heating bill. You must keep them from freezing all winter rather than just during bloom. Your heating bill just increased about 20 times. I won't try them without a good commercial grade heating system like mine. With that you almost need fans for cooling rather than natural ventilation because it is much easier to automate. Plus Mango are too big for pots. Citrus will work in pots but they too need freeze protection all winter. The pluot you listed would be the last two on my list. F Supreme is very hard to pollinate. F Queen is very sweet but lacks flavor IMO. The others on my list are better IMO. Good luck!!

I love them, but just be cautious about how fast and how wide they spread in a short amount of time. You'll probably have to thin yours out in a couple of years, so you'll have some to share with friends. And if they are near other perennials, shrubs, etc they will probably overtake them. Cannas, IMHO, are one of those plants I almost wish I'd never planted. I recently saw a large planter with a dark-leaved canna planted as a tall background plant that was very attractive. I'm going to try this next year. I figure I can make divisions from a potted one a little easier. Elaine

Thanks for the advice. This is rather a late update but I just wanted to say that soon after I posted this, I potted the tomato in a large container and kept it outside on my apt balcony. The white spots quickly went away on their own. I guess it just needed sunshine and better air circulation!

Java Plum can grow in Southern California or Florida in climate zone 10 (near the coast). I'm not sure about colder than that. Java plum is "an acquired taste", as they say. Many people who grew up with them love them, but the flavor can be very astringent. They are an invasive plant in the tropics, with the birds spreading the seeds everywhere, but this is probably not going to be a problem in the dry climate of Southern California. It is listed as an invasive plant in several counties in Southern Florida though. They are beautiful trees and can get to be very tall, but they are very messy, dropping their fruit everywhere.