Need advice on starting a tropical food forest

Thanks for the reminder!  I acquired many of the plants and I've had them in pots the last year and a half.  One slight hangup is that my greenhouse isn't naturally maintaining above freezing temps :(   Unless I add a heater, it gets down to 20F in there on the coldest nights.  

To skate by last winter I made a mini greenhouse inside the main greenhouse and moved all the nervous plants in there.  Last winter I still had hope of the greenhouse staying warm enough, this year I suffer under none of those illusions.  This winter I did make a temporary greenhouse for them but the quantity of plants will have to decrease in the future.

As for my list of plants, here's what happened:

bananas - they grew well in the ground.  Last year they got 8' tall before dying in the cold.  They actually made it down to about 32 before dying.
avocados - they are growing slowly but seem healthy
mangos - it's struggling and looks like crap but isn't dead yet
pineapples - they stay alive if I keep them warm but haven't fruited in two years so I'm not wasting space on them any more
cinnamon - didn't try since I felt I needed to put them in the ground
dragonfruit - grew slowly (1 foot in first year) but died before I had the mini greenhouse set up
ginger/turmeric - Grow ok in the summer but didn't come back up in year #2.
loquat? - didn't try
papaya? - I planted Mountain Papaya seeds in the ground and a couple grew but died come winter
miracleberry - it struggled for a half a year and died
vanilla orchid - it was doing great but died before I had the greenhouse set up
yagrumo? - didn't try
lemon - they do fine.  Harvested 5 lemons this year
mandarin - Growing well but no fruit yet

My current plan is to reimagine the greenhouse as a Mediterranean greenhouse with plants that can handle 15F.  Need to figure out that list this winter and make my plans.  Along with that I'll have a small part of the greenhouse that can be cordoned off with poly to keep warmer for winter growing.  The lemons and maybe another citrus will hide inside the edge of that area for protection while not taking up too much floor space.

Did you think about having a small meat chicken house inside the greenhouse? They don't need a lot of space and they will add some heat to maybe keep things above freezing. After 4 months of doing heating they can go into the freezer as a good measure for irony

No, I didn't really consider chickens.  I think I need about 100,000 BTU of energy on cold days to keep it above freezing.  I suspect that's a lot of chickens

A few ideas looking at your list of stuff, from zone 9b:

avocados & mangos - if you can keep them pruned to a size where they fruit and also can be moved in and out, I think you might be okay. Especially with the avocados. Mangoes are a tad more sensitive but avocados live through frosts here. I don't have a source, but I read years ago that there is a fruiting avocado in WI somewhere. Maybe worth checking out.
pineapples: I don't think you have a shot. Their season is so long. My uncle has them, he is probably two zones hotter than me and never frosts, and it is just barely warm enough to get a small stunted pineapple every once in a while. They need hot all the time.
dragonfruit: same as pineapple, growth is so slow that interrupting for seasonal cold means it's practically impossible
ginger/turmeric: probably worth trying again, especially turmeric (if you're so inclined). They will do decently enough over a hot summer, and you can also do them in containers to extend the season a bit.
loquat: you should try, if you`re so inclined. They do well with cold, maybe not wisconsin cold but they're a nice plant and I could see you getting one in a barrel to move in and out. The fruit is nothing exciting, compared to a WI apple, say, but it does have medicinal uses and it's pretty enough.
vanilla orchid: my dream, but they need total stability with no fluctuations. I don`t have time for that, not sure about you
lemon/mandarin: both should do just fine!

Thanks Tereza!  I think I could keep the avocados and mango to a 3'x3'x8' high shape.  Would I get much fruit from them if they were kept that small?  Any bigger and they'll take over my mini greenhouse.

I think you're going to have to try it and see. With good dirt and fertilizing i don't see why not! I may be mistaken but I'm pretty sure i read David the Good suggest dwarfing all sorts of trees with some yields; i mean a small tree has fewer branches so you're not going to get buckets but why not (I'm trying hard pruning in my yard with guavas, jackfruit,  and avocado, but it'sstill early days). And mangoes are routinely kept small in farm operations, pretty much the same as apples, otherwise the fruit is out of reach. My aunt has one thats not much taller than me that was just covered in blossoms last time i went there.

I did not see an outside picture of the greenhouse.

Did you berm up earth on the north side of the greenhouse for insulation and thermal mass?

Here's a thread all about it: Mike's passive solar greenhouse

I didn't berm earth up on the north side due to an access path being in that area.

Mike,
The video of my Texas greenhouse was taken years ago before many of the overstory trees had grown in. Calling them "overstory" is not always describing the current height, sometimes I was using it in context to describe the natural growth pattern of certain species. The over story trees are now about 35 ft tall and shade out as much area around them as I will allow through pruning and yearly height and canopy maintenance that is necessary to grow a food forest in a greenhouse. I hope that disambiguates what you saw in that old video.
Best,
Foxxotron

I grew up in Minnesota, and just this year moved to South Florida, so I am still figuring out the tropical plants, but I always dreamed of doing what you are! It's beautiful!!

Definitely papaya and dwarf bananas! A lot of the other things can be pruned hard to keep them under control, or dwarf varieties.

I don't think anyone mentioned ice cream bean tree. I don't know how big they eventually get, but they are a nitrogen fixer and in one year ours is still pretty small. They make pods with sweet fluff like nature's cotton candy! I have heard that coffee growers plant them together with the ice cream bean tree for the nitrogen as well as some shade for the coffee plants. The leaves are a beautiful shiny, deep green and I would grow the tree just for the foliage alone. I am still waiting impatiently for the first fruits!

My dad and I were so excited and planted TONS of fruit trees before we really knew what we were doing. We have run into so many problems with the pests and diseases that we didn't have in Minnesota. I bet you would have a lot more luck with them in the greenhouse without the pests and diseases, as well as having the ability to control the environment! Some day...

Is the Mitchell Park Conservatory in Milwaukee still open? I made many visits to the domes while growing up. The tropical one was my favorite. If it’s still there, it might be worthwhile to chat with the people who care for the ecosystems in there.

Hi Mike and followers,

Congratulations on your project!

We are soon moving to a tropical country.

I am unfamiliar with tropical farming, so I wonder why you need a green house in the tropics.

Thank you,
Anouk

Hi L, yes it was there two years ago when I was last in the area.  I like the Como conservatory in Minneapolis even better.  Both are a long drive from my location.

Anouk, I don't live in the tropics.  I live in a frigid temperate climate so I need a greenhouse to get closer to tropical conditions.

have you thought of trying strawberry guavas, prolific and desirous

Mike
I just googled the Como. What a treasure! The “big idea” behind Mitchell parks is really the  domes themselves, finished in the early 1960’s.  Fun fact:

Shape
The world's only conoidal (not geodesic) glass house; the unique shape allows a better angle for solar heating and more height for tall trees. (https://milwaukeedomes.org/domes-technical).  

But the Como - that looks like  a whole world unto itself. Thank you for posting about it.  If/when I get back to Wisconsin (Mikwaukee is my hometown) I am definitely arranging a side trip.

I hope you continue to post about the progress of your project.  I was surprised to find that I can grow figs and pomegranates outdoors here in the Willamette Valley, but I do dream of growing my own avocados and  papayas. Especially the papayas.

Add passionfruit. A must have with a miraculous flower and fruit with an amazing tart sweetness balance. hugshugs

Did you have any luck with the Tropical Greenhouse, that you posted about 3 years ago?  I would love to hear more about it!

Lisa Richards wrote:Did you have any luck with the Tropical Greenhouse, that you posted about 3 years ago?  I would love to hear more about it!

Me too!  

There is a place that is called "Greenhouse in the snow"  it uses geothermal for the greenhouse in Nebraska


https://greenhouseinthesnow.com/

I have an unused in ground pool turning into a greenhouse.  https://www.urbangardensweb.com/2017/08/26/transform-disused-swimming-pool-garden/

maybe even primarily for my trees citrus, peaches, mango, avocado and banana.  who knows.  Im excited to see how it goes for you.

Vee SuRae wrote:There is a place that is called "Greenhouse in the snow"  it uses geothermal for the greenhouse in Nebraska
https://greenhouseinthesnow.com/
I have an unused in ground pool turning into a greenhouse.  https://www.urbangardensweb.com/2017/08/26/transform-disused-swimming-pool-garden/
maybe even primarily for my trees citrus, peaches, mango, avocado and banana.  who knows.  Im excited to see how it goes for you.

Wow, thank you for those two links!  Is that urban garden article about you?  What a great idea!

Up above is a more recent post about my successes and failures and here's a direct LINK to it.

I've fully embraced the majority of the greenhouse being for Georgia climate perennials.  I got two peaches this spring and they're doing well.  Figs, grapes and pawpaws are also growing.  In the NW corner (where the compost heat system used to be), I've more properly enclosed the tropical greenhouse part so it looks better and holds heat better.  I remove the glazing for the summer and put it back up when it starts to get cold.  I planted my citrus in the ground in there this spring and they preferred that to their pots.  The space is limited in there and the sun only hits it from the side so I'm not thinking I can do too much more with it unless I want to run lights.

What a beautiful greenhouse Mike! Where did you get the construction plans from? Is it made of wood beams or metal? Hard to tell specifics from photo. Also neat idea to put a water container up high for gravity flow to irrigate. The platform must be very sturdy - again what are the construction plans? Thank you.

Thanks Denise!  The plans are on a bunch of random graph paper in my office.  I designed it myself.  The curved rafters are made from wood.

We actually haven't used the water tower much yet.  Since it gets below freezing in mid winter I haven't used it until just now.  For a few years we've watered with a watering can.  This summer I hooked a pump to a nearby rainwater collection system to have pressured water.   At the end of summer I pumped rainwater up in there and we're using that to water for the next month or two.  Once it gets too cold, we'll go back to watering cans and a couple 55 gallon drums of water.

Mike, have you thought about putting a cattle trough heating coil inside the water tank to keep it from freezing?  They come in different shapes so there should be one to fit inside the opening. Maybe considered 'cheating' a bit as it would use some electricity but it would allow you to keep watering system going.  Did you cut the openings in the front curved trusses to minimize weight or is the opening something else? I think you should share those plans online someday when you have time.  What about growing some groundnut plants? They are like air potatoes and could grow up vining through those holes in your front rafters! :)

I should have posted a link to where I found them and learned about them. There are different varieties - so not just your ordinary "peanut". Check it out: https://oikostreecrops.com/products/perennial-vegetable-plants/groundnuts-apios-americana/

When I was a kid living on our farm, we had a White Mulberry tree in the back of our house. I can tell you, when the fruit was ripe and dropped off the tree, it was a huge mess.  Since the fruit was plentiful and sweet, it drew literally hundreds of bees!  A Mulberry tree in such a confined space, I believe would be a big mistake.  

Good luck on your project!

Thanks Denise, that's a great idea!  I'm not sure how much water we'll go through during winter so if there is still some in there come late December, I'll give that a shot.

I did mean to create plans for it and I took a bunch of photos along the way.  I lost steam when it didn't stay as warm as I had dreamed.  But I'm pretty sure if my greenhouse was in a balmy location like Chicago it would stay above freezing all winter.  Or especially if it was somewhere where it's sunny most days in the winter.

The rafters are shown pretty well in this post: https://permies.com/t/160/76165/Mike-passive-solar-greenhouse-design#734038.  The holes are really just spaces between the chunks of wood that do all the work.  Kinda like the web of an I beam.

Groundnuts sound like a good one to try.  I did passionfruit one year and they grew well but died in the winter.  I think they were a true passionfruit, not a maypop.  I kinda don't want to cast too much shade for the interior of the greenhouse so training them up the back rafters or some central posts might also be an option.

Thanks Sandra, I'll skip those

Mulberries - There are so many different cultivars you can almost dial in what you want. In a small space I would lean towards the dwarf ones like Gerardi (tops out at 6 - ft.) world's best, Jan's Best and the like. Everbearing Black mulberry is the usual choice for container growing. Most dwarf mulberries can grow in a pot and be pruned regularly to produce more fruit and check their size. Here's a good vid on that:

https://www.logees.com/dwarf-mulberry-dwarf-everbearing-morus-nigra.html

You can also do incredibly radical pruning and leaf stripping every 45 days and get WAY more fruit output from any mulberry. I hesitantly butchered my black mulberries this summer just like this next vid suggests and,  just as the vid claims, they'll grow back with a vengeance and put out a lot more fruit. The leaf stripping was a pain so next year I'm just going to do the pruning part and see if that works as well. Here's that vid:

https://www.youtube.com/watch?v=IuzAXHspxCE

Of course, we'll have to include our Florida queen of mulberries here, Jan Doolin. She sells cuttings and they're top flight quality. The ones I've grown from her cuttings outpaced any others. She has such a vast collection of mulberries that she has found and then planted on her property that you can get some really unusual cultivars from her.

https://www.youtube.com/channel/UCG5KPn4rFCvo9XKTKVFXERw

Best, most accurate info on growing, care, and understanding all the weirdness of mulberry cultivars:

https://www.growingmulberry.org/home


One more....a tropical tree that not a lot know about but is truly awesome, Muntingia Calabura/Strawberry Tree/Jamaican Cherry.

This is the only truly tropical tree I bother to hard prune and stick in the greenhouse or otherwise away from the frost. It makes large quantities of the closest thing we're going to get to little tiny cherries here in the hot zones.
You can pick fruit twice a day in summer.
The strawberry tree moniker came from the flowers looking just like strawberry flowers.
It would grow to 30 feet left alone but you can do massive pruning on it and keep it well within any bounds you have.
I grow it in a 10 gallon container and it's fine.
Here's Logees again with the details:

https://www.youtube.com/watch?v=Bup4WBP9wG4

Hi Mike, love your project! So envious! You must have made some progress by now. Hopefully you come back to post an update.

I’ve been collecting more unusual delicious and “tropical” plants or fruit trees. I tend to get one or two a year to add to my collection. Having just one new one at a time to watch and baby and monitor, when I do have a full time job and other gardening, makes “learning” the new one and getting it right more manageable and do-able.

I don’t have a greenhouse, so everything’s final home is outside. I have a surprising amount in pots, (everything?) and they are doing great.

When I can I buy ones that are already living outside because they are hardened off and doing fine in our climate. I generally start with smaller plants, because they’re cheaper, but also where possible that are bigger than seedlings, so I’m not going to immediately kill them while I’m getting it right. If they are young plants I start with them inside, or maybe if I get them during winter, and then when they’re bigger I gradually harden them off and then put them outside.

I have found it easiest to get new plants in the spring or maybe end of winter, and then they can adjust to the climate and change in temperatures more naturally.

Where I live there is no snow, we have mild winters, and it’s a tiny bit humid in winter. I live in Auckland, New Zealand, which I guess is technically sub-tropical, but I’ve found out that a lot more “tropical” plants can grow here than I thought. It’s been great. So I hope you have similar luck.
Probably your greenhouse will be similar to or even more “tropical” than our climate here. So if I can do it, you can do it!

I recommend feijoas because they are very hardy, (probably they aren’t tropical, just subtropical) cherry guavas, cherimoyas, and tropical guava. They all do fine and are actually easy in our climate. I didn’t know that before! Yams, boysenberries, blueberries, yacon, choko, lime, satsuma mandarin, figs, ginger and galangal, potato and sweet potato are all also great and very very easy. I have everything except feijoas in containers, and they are all growing and fruiting beautifully. I have some young peaches and peachicots, so we will see how they do.

I didn’t manage to keep my mango alive, but now I have a papaya that I’ve grown from seed, and I’m keeping it inside for the first 2 years, and I have my eye on getting starfruit (surprisingly, them seem to grow fine here!) or babaco (it’s apparently more cold tolerant than papaya) next. I think mango need more heat than papaya, and papaya need more heat than tropical guava, and tropical guava like more warmth than babaco / star fruit / cherry guava / feijoa. The yellow or red cherry guava can handle different conditions, and feijoa can handle cold too. So they are surprisingly adaptable and hardy.

I would love mangosteen!!! 😋 Such an amazing fruit. 😍 But according to what I’ve read it might not work here. But who knows…

Hopefully you can come back and update us!

Hi folks, thanks for the continuing interest in my greenhouse!  Nothing much has changed in the last year.  I got preoccupied with some other stuff so the greenhouse system is just coasting along for now.  The peaches grow too fast!  I prune them in the spring and they put on 10' of growth by the end of summer!  I got tons of flowers this spring but they all curled up, I think due to too high of temps.  I need to activate the ventilation earlier in the year so they don't overheat.  I thought the figs would grow over the peaches but they keep dying back to the ground and then being shaded by the peaches.  If they don't do better soon, I might have to do something about that.

I have an olive tree in there that pushes new growth too soon in the spring and gets nipped.  But then it recovers by fall with much more new growth.  The pawpaws are about 2' tall now and should really take off next year.

The citrus in the old compost area are growing very well in the ground.  They keep leaning out towards the sun so hemming them back in with the poly plastic in the fall will be a challenge.  That reminds me, I gotta get on that as the outside temps are starting to fall....

Sorry for the brief update, I need a greenhouse fairy to spend an hour a day in there making it pretty :)