Greenhouse within a greenhouse for ultratropicals?

[Tropicaltoba]

So I realize that in trying to grow fungus free organic mangos it is impossible to get the humidity/temp high enough for ultra tropicals like Langsat, mangosteen, and pulsan. So I’m trying an experiment so see if I can make a cheap mini greenhouse inside my already small greenhouse. With the goal of always have rh at 80% and temps no lower than 25C.

I’ve seen similar designs for sale but with their small
Air volume (15 cubic feet) and poor ventilation I suspect they would normally overheat like crazy outside in the sun. With my greenhouse being “climate controlled” 15-32C and 50-75%rh and 30% loss of light transmission. I’m gonna make mine a little bigger with a volume of 36cubic feet

Has anyone tried this in the past? And if not do u think it will work?

[K-Rimes]

It's entirely possible to keep ultra tropicals alive in the wrong climate, but it's entirely another for them to thrive and thusly fruit. Seeing the absolutely insane greenhouse set-up at Fairchild in Miami specifically made for durian and stuff was insane, but that's basically the best outdoor climate + the best indoor climate and they still say it doesn't do that well. We got to chat with Dr Campbell about the build out and how they imported acres of acid soil for the project and everything and it's still not doing amazing.

The main issue I see with these ultra tropical set-ups is that you need them to be in grown in the earth, and then you need a variety of back up heating methods. Say the power goes out and you lose your heaters? Say the gas line busts and you lose your natural gas heaters? Are you home in time to get the propane back up heats going?

Way too much work and investment for me, personally. Spend that money traveling to SE Asia and stuffing your face for a week. Money well spent. If you are borderline zone wise, a bit of pushing is cool - but your losses will be tremendous in my experience!

[Tropicaltoba]

K-rimes
Thanks for the info on the durian if I make is down to florida I’ll have to check it out. I know it’s crazy, I’m more into it for the challenge. My greenhouse is tiny 225sq ft and attached to my house so if the electricity fails (ir heaters) then I can just open the doors to the house. If the gas furnace fails the plants will be fine and my house will be #%^*’d with all the frozen and burst pipes.

[K-Rimes]

K-rimes
Thanks for the info on the durian if I make is down to florida I’ll have to check it out. I know it’s crazy, I’m more into it for the challenge. My greenhouse is tiny 225sq ft and attached to my house so if the electricity fails (ir heaters) then I can just open the doors to the house. If the gas furnace fails the plants will be fine and my house will be #%^*’d with all the frozen and burst pipes.

A lot of those trees really want to be huge. Rambutan / pulasan I hear should be planted on 30' centers. I applaud your desire to grow cool stuff, but wow, your heating bill will be ridiculous for that much space at those temps. Do you have a greenhouse that's built on a foundation with double pane windows? That's kind of the only way. I would think foundation would need to be at least 4' deep, and then you'd need really high quality acidic soil where you are planting stuff in ground. These are not really "pot culture" type trees like jaboticaba or eugenia.

The durian tree at Fairchild is probably 30' tall and not fruiting well. Do you have that much vertical in your GH?

I was really excited to push my zone from the 9b it is and attempted 10a plants. Most all died. I just caution you not to spend so much money on this project...

My mom was born in "Winterpeg", it's cool to see someone growing stuff there but wow, that's a REAL winter up there.

[Tropicaltoba]

K,
I’m assuming she got wise and went south? It’s actually more of a conservatory, it sits on the second floor. I designed it myself and spent too much time and money on it, but I was interested to see what was possible. Also I like big challenges and trying to think outside the box. I still haven’t totally figuredout what I want the space to be yet but if I can have a climate where the plants are thriving maybe I set it for ultra tropical.

[fruitnut1944]

I had a 10x20ft GH inside my 32x54ft GH last winter. It would maintain +5 to 6 C additional temperature with a 1500 watt heater. So with the big GH at 10C I could get 16C inside the inner GH. I don't plan to use it again because I'm changing the basic setup of the GH.

I am planting both Mango and stonefruit and hope to hold the mango warm enough during the 45+ days needed to get chilling on the stone fruit.

I'm in a much warmer and sunnier climate than you so if the heater holds out and I don't get cheap this should work.

What would work well in your setup is stonefruit and figs. The stonefruit I've grown in the past has been sensational. So if you want a good yield of great fruit set your sights on figs, nectarine, pluots, apricots, and sweet cherries. It would be way more fruit for way less effort and expense.

[Tropicaltoba]

Fruitnut,
Yeah I actually want to run the gh cooler so I can chill the golden prolific nectarine I have. I was able to get peaches (my family hates the skin) 4 years ago but they only needed 400 chill hours, the nectarine needs 800! The problem here in Canada is there is a strict ban on importing stone fruit trees from the US and all our trees are bred for cold hardiness not low chill.

I find the the chill hours estimates are inconsistent. I heard stories of some cultivars of under chilled apples producing very well in southern CA.

I also don’t know how many chill hours I can accumulate in my gh as when it is cloudy close to the window it can be 50F but as soon has we get a sunny day in January to can go up to 80F.

[K-Rimes]

K,
I’m assuming she got wise and went south? It’s actually more of a conservatory, it sits on the second floor. I designed it myself and spent too much time and money on it, but I was interested to see what was possible. Also I like big challenges and trying to think outside the box. I still haven’t totally figuredout what I want the space to be yet but if I can have a climate where the plants are thriving maybe I set it for ultra tropical.

She went west to Vancouver. I grew up there but have been in CA for almost 10 years now.

Your set-up is fabulous, and I take back what I said to some extent. You can grow some amazing things in there, I am sure, but your selected ultra tropical plants may be especially challenging. I see a lot of rare fruit dreamers (am one myself) that have a dinky little greenhouse of just 5mil sheet (what I am using) thinking they can pull off ultra tropicals and tend to think of those people more than your super cool build.

Kudos on that conservatory, that is bad-ass.

[brian]

I think it will work for anything that could fruit at a small size.  I have my greenhouse set at 55F in winter and have had a purple mangosteen seedling growing for years (verrry slowly, but it seems healthy enough).   I forget what qualifies as ultra tropicals.  I have a marang and pedalai in ground that look happy.  Chempedak seems fine so far but I just put it in the ground.  I can't get rambutan seedlings to even survive more than a couple months, but I think its the soil mix not the climate.   Durian seemed happy then constantly gets attacked by spider mites.  Rollinia and Soursop in ground are happy with the climate and flowering but want to grow big and also constantly under spider mite attack.    Abiu in a container is super healthy and flowering.  Kepel seeds die as soon as they sprout.  Pulasan dies as soon as it sprouts. 

As far as backups, I haev some propane tank manual heaters, enough to survive a few days without power.  And I am thinking of getting a solar panel array for emergency cooling in case there is a summer storm that knocks out power followed by a hot sunny day.   The biggest issue is quickly detecting an outage and responding to it.  I haven't found a reasonable thermometer that uses cellular for alerts, only wifi, radio, and text message stuff that isn't reliable

If you are looking for a cooling solution evaporative cooling works wonders if you have a clean water suppply. 

Just noticed your photo, that look great and reasonably well insulated.  Can it tolerate high humidity without affecting the surrounding structure?  If so I would just bite the bullet and turn the thermostat up and have the whole thing be "ultra tropical greenhouse"

[Tropicaltoba]

Brian,
I have it completely sealed from the rest of the house with a roofing membrane. On a roof it’s rated for 25 years, I’m hoping it lasts longer under glass.

What I really want is to grow great tasting mangos, u can t get good ones here. I am worried they’d get ancanthranose. I read a paper that said >27c and 75% rh is the cutoff for when ancathranose get bad.

I also want to grow stuff u can’t get in Canada. Do u know if your other ultratropicsls ( chemp marshy etc) will bear fruit in container or if small?

[fruitnut1944]

I can get enough chilling for anything in 45 days. An average of 16 Utah chill hours a day. 45 days equal 720 hrs. That's with mid winter temps of 60/32F average and 75% sunshine. My thought is any place in Canada would have trouble not getting enough.

Heat to 5C at night and hold days below 10C if possible. Neither one should be that difficult if the GH has good heating and cooling systems.

Everyone seems to want what they can't have. When what you can have is better and cheaper.

In Canada if I wanted to grow real tropicals I'd do it indoors in a highly insulated building with LED lights. That would be cheaper and much easier to control both humidity and temperature.

[brian]

I'm certainly no expert on ultra tropicals, but I think I've read chempedak will fruit at reasonable size.  However, none of the artocarpus I've tried to grow in containers do well, but they all do great once I put them in the ground.  Likely the soil, as the container ones aren't root bound.

I have had a mallika mango in ground for years and it looks great.  It first flowered three years ago but fruitlets never got past pea sized.  Two years ago fruits held on longer/bigger but still not to maturity.  Last zero blooms or fruit set.  It is blooming heavily this year so hopefully I'll get a crop for once.  I have recently read they don't like water while holding fruit and I was always watering it constantly, have sinec stopped that.  The tree itself has been very healthy aside from a minor armored scale infestation and resultant sooty mold.  I'm not exactly sure what anthracnose is but I don't think I have it.   You should be able to grow one. 


I suggest you buy a bunch of small seedlings and see how they do, and if they do well replace them with grafted types.  I found almost everything grows well and the ones that don't are for reasons I can probably correct.  It will never be efficient but it is entertaining. 

[brian]

also supposedly the reason that tropical guavas are not so popular is that they get destroyed by fruit flies in Florida.  Those flies don't exist in Canada (nor in Pennsylvania  )  and these guavas are easy to grow and good producers

[Tropicaltoba]

Fruitnut,
About 10 years ago I built a grow room in my basement in the old coal storage room, it worked ok for winter tomatoes and overwintering citrus at rh of 50%. I later got one of those huge tents (10x10x8). There were some issues with the humidity and the heat from the light (which I could have figured out) but the biggest issue was it was not a space I enjoyed being in and half of
My plants died of neglect. That was why when we did a kitchen reno (what’s underneath) and had to replace the flat roof (on which I did hydroponic peppers and tomatoes in summer) I thought what the hell, let’s go big.

When the sun is shining in my greenhouse I never want to leave, and it was the best thing during lockdown.

[Tropicaltoba]

Brian, I love my cattley guava. Nice looking plant, No pests at all and fruit continuously. I have a ruby supreme and it is a magnet for scale, whiteflies and mealy almost ready to get rid of it.

[brian]

...

When the sun is shining in my greenhouse I never want to leave, and it was the best thing during lockdown.

Yup, that's the thing about efficiency... the most efficient "greenhouse" at your latitude is probably an insulated warehouse with grow lights.  But it won't feel very nice to be in.  Better to spend money on nice environment you like being in even if it isn't very efficient. 

[TropicalFruitSeeker]

Just chiming in as an out-of-zone tropical grower, I think I can speak for a lot of people here and say your set up is amazing. Thats the type of build I would go for if space and money were not an issue.
Also, @Brian, so sad to hear about the Kepel not growing well. Kepel is my white whale, but I think I'll have to bite the bullet and just go to where it grows naturally to try it.

[brian]

Just chiming in as an out-of-zone tropical grower, I think I can speak for a lot of people here and say your set up is amazing. Thats the type of build I would go for if space and money were not an issue.
Also, @Brian, so sad to hear about the Kepel not growing well. Kepel is my white whale, but I think I'll have to bite the bullet and just go to where it grows naturally to try it.

I think it must either be hard to grow from seeds or my container soil sucks.  Next time I get a seedling I am going to try just sticking it right into the ground.  Anything that dies this quickly it has got to be a soil/disease thing and not climate

[Jaboticaba45]

I tried this with breadfruit. Gave up. Takes way too much space anyway for something that will never fruit. But I think if in the right area and conditions you could potentially make it work.

[brian]

I know breadfruit trees can get huge, but are they capable of fruiting at a small size?  I never tried because I only like fresh eating fruits, but I wouldn't count it out based on climate alone if you have a greenhouse.  I don't know much about breadfruit specifically but all the other artocarpus have been surprisingly easy to grow (so far)

[Jaboticaba45]

I know breadfruit trees can get huge, but are they capable of fruiting at a small size?  I never tried because I only like fresh eating fruits, but I wouldn't count it out based on climate alone if you have a greenhouse.  I don't know much about breadfruit specifically but all the other artocarpus have been surprisingly easy to grow (so far)

Probably not lol. Neither marang and the other artocarpus. Jackfruit and chempejack (hypothetically) could be done as we've seen with Tropical Fruit Hunters. I got rid of mine though it's not worth my space for a few jackfruits a year. I'd be surprised if you could fruit chempedak. If you do, that's a huge feat. I have a friend in FL with greenhouses with marang and pedalai and his haven't fruited yet and they're hitting the roof of his 20ft greenhouse. They just get too big. Now we can fruit kwai muk and lakoocha easy though. Just am waiting for my trees to grow more.

[MisterPlantee]

Exactly my problem too with my Ruby Supreme, mealie bug magnet, and almost impossible to get rid of all of them because the leaves are ribbed and they hide underneath Now I just hard prune all the branches off before going into the greenhouse. My mango tree normally is pest free but in the winter in the greenhouse they also get mealies.

Brian, I love my cattley guava. Nice looking plant, No pests at all and fruit continuously. I have a ruby supreme and it is a magnet for scale, whiteflies and mealy almost ready to get rid of it.

[K-Rimes]

I have had a mallika mango in ground for years and it looks great.  It first flowered three years ago but fruitlets never got past pea sized.  Two years ago fruits held on longer/bigger but still not to maturity.  Last zero blooms or fruit set.  It is blooming heavily this year so hopefully I'll get a crop for once.

One of the major issues I have even in my outdoor greenhouse is pollination. Even trying to pollinate by hand, I don't get a lot of sets on stuff in there. When I removed them and put them outdoors where there are bees, much more fruit! I even got my own colony of bees this winter and more for spring which I hope will sort out the greenhouse by sheer numbers (though it is sad that the bees get stuck and die kind of often).

[Tropicaltoba]

K,
For a while I was looking into carpenter bees in my greenhouse, I think you can have little wood block houses for them to lay eggs in. Issue is they need chill hours. I think when I looked at it you’d have to have a set of thee houses to have bees year round. The issue with bees is u need year round nectar/pollen

I have been able to keep a couple of species of hoverfly alive over winter in my greenhouse, I make sure that I have winter flowering plants (I also have leds running in winter). I’m not sure if bees are light sensitive in term of dormancy like some predatory bugs.

I hand pollinate my passion fruit vine with a birch on a 8 foot stick, I still miss about 10% of the flowers though.

[fruitnut1944]

I have had a mallika mango in ground for years and it looks great.  It first flowered three years ago but fruitlets never got past pea sized.  Two years ago fruits held on longer/bigger but still not to maturity.  Last zero blooms or fruit set.  It is blooming heavily this year so hopefully I'll get a crop for once.

One of the major issues I have even in my outdoor greenhouse is pollination. Even trying to pollinate by hand, I don't get a lot of sets on stuff in there. When I removed them and put them outdoors where there are bees, much more fruit! I even got my own colony of bees this winter and more for spring which I hope will sort out the greenhouse by sheer numbers (though it is sad that the bees get stuck and die kind of often).

A class C hive of bumblebees has given me good pollination in my GH. They last about 5 weeks which covered most of what I had.

If I get mango that may be another story. But mango are wind pollinated. I may help out with a leaf blower twice a day. Or spray with a misting of water. That can help some things.