guava and mango? Also semi-dwarf citrus. Figs can be pruned.

As desertdance suggests, Guava is nice and easy (there are tropical and subtropical species...I only have grown the tropical ones). Mangos too are good, even small one WILL produce fruit. Try to get a dwarf though...like Cogshall/Condo mango. Lots of the tropicals are really quite easy...
Sugar cane, ginger, bananas are easy enough for beginners (try the dwarf cavindish.). Subtropical kiwi is a vine that is super aggressive and lush (so much so that I had to remove it from my outdoor garden here in NJ, so sure it will do fine in a greenhouse in Nebraska...but it is deciduous). Passion fruit for fruit and flowers is nice. Citrus, if you go that route, is ADDICTING, so try...kumquats, Meyer Lemons, ponderosa Lemons (enormous), Washington Navels, Blood Oranges, grapefruit, Persian Limes, Key Limes, pomelos, Valencia, mandarins...you got the point?! Loquats are just about cold hardy here outside of greenhouses (except for last year), so if heating is an issue...LOQUATS! Figs are also very cold-hardy. Best of luck!

Very very cool, bee tree - I can just see this is going to be a VERY FUN project for you. I like the varieties other folks have mentioned.How about adding Papaya to the mix, if you like them. There are vines too - passion fruit, dragon fruit, oh lordy there are sooooo many things you could plant.

Go online and see what's out there....or maybe go to a site that sells tropical and sub-tropical plants and you will get tons of ideas....

Gosh, I want to see a picture of this Monstrous greenhouse when it is completed...

M.A.Dawg

Dragon fruit, climbing cactus supported by a trellis.

Cool flowers.

Cool looking fruit.

DM

Mine isn't tropical, more temperate fruits that need winter chilling. If you decide to build another it would only need to be 12-14ft for my crops: citrus, figs, grapes, kiwi, blueberry, blackberry, and all kinds of stone fruits.

Why 25ft tall? You could grow anything in one 5-10ft shorter. It will need to be super ultra strong at that height in NE.

Here is a link that might be useful: greenhouse fruit production in west Texas

Thank you all so much for your posts.and I am building it 25ft tall for some of the fruit I have eaten and REAlY loved such as rambutan avocado jackfruit dwarf coconut and large papaya trees heating is not a problem it will stay 75 in there all year and it will be done in 8 months. The goal is to have a small tropical fruit forest here in zone 5 Nebraska I did not think of putting citrus mango and guava in there as well great ideas thank you all.

This post was edited by beetree on Tue, Jul 29, 14 at 20:22

Even the 'tropical' guava is easy (Psidium guajava), and mine has to survive some degree of Winter cold as well...will even come back if leaves are shed! Regarding the papaya...there is a dwarf variety readily available and I love it! Seems more robust than the others. Some others to consider...

Cafea arabica (coffee)
Bay Laurel (more mediterranean/subtropical), but easy
Lemon Grass (an herb popular in Thai cuisine)
Chili peppers
Eggplants
Tomatoes

I'm interested in how you are heating the greenhouse with wood?

Bump, did you get it done?

there is cold-hardy Kiwi. i grow Jujube which is fairly cold-hardy. fig, loquat, pomegranate, longan,, lychee , citrus all have some tolerance.

I would stay away from rambutan, mangosteen, cacao, breadfruit, jackfruit, coffee, banana, papaya... i am in zone 9 and stay away from all of them (i plant banana and papaya but almost always die in winter)

check the tolerance (zone) before buying a plant or seed.

I think he realized by now...just adding heat does not a tropical greenhouse make. You need humidity...even warmth. 80f at the peak and freezing near the soil line in Nebraska is going to be rough on plants.

Pests- Mango plants in greenhouses are very susceptible to scale,whitefly. Coffee,same and aphids.

Greenman was right...better cool growing plants that are still very exotic for Nebraska. Strawberry and Pineapple guava's,Kiwi, Flowering Cassia' and Jacaranda tree's. A whole range.