How To Build A Tropical Greenhouse In Cold Climates

Note From Lindsay:  This is a very special guest post from my friend Jay at Tropical Fruit Hunters, who grew these jackfruit in his tropical greenhouse in Ohio. I’ve occasionally gotten questions from readers in places like Russia, Iceland and Slovakia (not making this up) asking how to grow durian in extremely cold environments. In this post, Jay shares how to build and maintain your own personal tropics even when there’s snow on the ground.

Above is my Jackfruit.  Just one of the many reason why I have a greenhouse today.  Others that will soon fruit again are longan, cherimoyas, starfruit, sugar apples, and more.

My obsession with tropical fruit probably began around 2003.  I started off with some various citrus trees.  They not only had attractive foliage, but their blooms smelled wonderful.  I had also recently come across a tropical fruit forum and discovered that there were other people growing tropical fruit trees other than plain old citrus.

And wonder of wonders, there were nurseries that would send me these plants…even to Ohio! 

I quickly took advantage of this and ordered a Nam Doc Mai mango, which is a Thai mango.  What better way to get my Thai wife on board with this purchase but to tell her I was bringing a little piece of Thailand home to her?

My second trip to Thailand with my wife finally started opening the door to a whole new world of tropical fruit.  I’m not talking your super market peaches, plums, and apples either.  I’m talking mangosteen, rambutan, longkong, mangos, and so much more.

Before long I had seeds arriving from all sorts of places and as well as more mail order trees such as longan and lychees.

My little 10’x10’ grow room was a spare bedroom on our second floor and
it was getting packed full of various seedlings and grafted plants.

I really started to hate the months of October and April. In Ohio, the weather can swing from being in the 80’s to snow, then back in the 80’s again.  These tropical fruit trees could not tolerate such low temps so my wife and I would haul all of the plants inside overnight, then right back out the next day if the forecast was pleasant.  I hated all the trips up and down the stairs.  The more plants, the more trips.

Something had to give soon.

Not only was the grow room crowded, our deck was a mass of containers, screens, PVP pipe holding together a crude misting system, and shelves.  I needed more room and better methods of caring for these plants.  My tropical fruit cultivar needs/wants were starting to get more and more exotic.  I wanted to grow the same fruit as I ate in Thailand.

Too many people told me too many times that I could not grow these trees in Ohio.  I was told it was a waste of time.  I’m a hard headed guy.  I really wanted to be able to grow these trees and all the naysayers did was challenge my whole idea.  Game on!

A tropical greenhouse was the only solution.  I didn’t know a soul with a greenhouse.  So for more than a year, I scoured the internet and forums, made lots and lots of notes, called many manufacturers, then researched some more.

Designing A Tropical Greenhouse

My goal was to have a large enough structure to house the plants I wanted to grow.  The structure would have to stand up to our brutal Ohio winters where temperatures can and do hit -20 degrees Fahrenheit.  We can get lots of snow as well.  We sometimes average 20 inches.

So my structure needed to be sturdy and insulated.  I also wanted glass.  Nothing beats the vision and beauty of glass.  And glass meant more light available to my plants.  Last and most important of all, the structure had to pass my wife’s main requirement…it must NOT be an eyesore.  All of this meant the structure would be more expensive.

The alternative to glass was polycarbonate.  I don’t find this material to be attractive in the least and it distorts vision.  Start added multiple layers and it just gets worse.  So this material was never in my consideration from the get go.

After much consideration, I settled on a lean-to design attached to our home from a sun room manufacturer for the following reasons:

• I determined that normal greenhouse structures were not suitable for my needs.
• Sunrooms, or four season rooms, are large, and designed to stand up to the elements.
• Sunroom structures are more attractive…remember my wife’s main requirement?
• I didn’t have to purchase a fourth wall…structure nor glass
• One less trench to dig for the foundation, less gravel, less concrete.
• This would give me the added thermal benefit of the house being the fourth wall on the northern side.
• I don’t have all that big of a yard to start off with, and having a structure right up against the house still gave me some back yard.

The size would be 22’ deep and 26’ across with a ceiling height sloping from 9’ to 13’ where it attached to the home.

Sunshine Rooms turned my requirements into a structure that arrived in many pieces on a FedEx semi-trailer.  Nearly every piece in that freaking truck was more than I could move or carry by myself.  It was nearly more than even a buddy and I could move or carry!

The structure itself was quite expensive.  I won’t say the total but just the cost of having their team build my structure would have been $17,000.  No freaking way!  I would build the damn thing myself.  I would later second guess this decision many times.

Building A Tropical Greenhouse

I won’t go into all the detail about city permits and inspections but if you are planning on something like this, you should check into your local laws.

The foundation, knee wall, and patio all had to be completed before the actual building of the structure.  This was a lot of time and hard work itself.  There were no easy days here.  I was lucky to have a good friend that worked block and concrete.

Once all that was behind us, we got busy on the structure.  I am not an engineer nor do I work in construction.  I’ve never seen a blueprint and I have certainly never took on a project such as this.  I was completely out of my depth in knowledge and experience.

What I did have was an endless supply of determination and a very understanding and patient wife.  I am still breathing, still married, and still amazed that she didn’t smother me in my sleep!

But seriously, I had no clue what I was doing.  This went beyond putting drywall up in the garage or installing a new storm door.

The instruction booklet seemed to be more of a guide than instructions. The detail came from the blueprints.

It took me a while to learn what each piece was…and there were a lot of pieces.  There never seemed to be an end to them.

The entire project took us all spring and summer.  I tackled this project every day after work
and from sun up to sundown on the weekends.

My dad and brother helped me install the large support beams and my
brother later helped me install the ceiling glass.  My good friend Harold came out several
weekends and was not only a good extra set of hands, but my sounding board as
well.

My wife was operating in many modes.  She not only helped out tremendously when I needed a hand, but she took on nearly all of the other home chores as well.  She knew how stressed out and how burned out I was on this project.

Once the structure was completed, I still needed to install all of the electric such as ceiling fans, exhaust fans, circulating fans, greenhouse controller from Bartlett Instruments,
outlets, lights, and more.  There would be a greenhouse fogger to raise humidity levels from Fogco.  All of this required special electrical touches… and skills.  My cousin is an electrician and he saved my butt big time here.

Electricity scares the hell out of me and I certainly don’t understand it much.  The electric alone was a huge project and took us at least another month.

Heating A Tropical Greenhouse

Next was running water and natural gas into the greenhouse.  I had to heat this thing.  I currently have settled on two 20,000 Btu heaters from Southern
Burner.

I wanted to keep up good growth throughout the winter, so I planned on keeping the temps around 70
degrees.  This would become my own personal tropical oasis even when it was cold and snowing outside.

The downside to these temperatures would be the additional costs to our fuel bill.  This sometimes amounted to maybe another $150 a month during the worst cold spells.

I will add that I got constant grief for keeping our home much colder during the winter than I did in
the greenhouse.  Each time my wife would come into the greenhouse, she would stop and say “ohhh… it feels so good out here!”

Cooling A Tropical Greenhouse

Ohio summers are hot. So the heaters are turned off and covered up.  The greenhouse controller would automatically open one window and kick on two ceiling exhaust fans when the temperatures
started to climb.  The fogger played a dual role.  Its main duty was to provide humidity but it was also used to drive down temperatures if the windows and exhaust fans could not keep up.

Solar Heat and Lighting

The glass was a good choice.  I wouldn’t have it any other way.  The greenhouse faces south so it always has sun during the day.  The plants get all the possible light that they can get.

Winter is a different story.  There could be several days in a row where we never see the sun.  Ohio is not known for a lot of sun in the winter and it gets drab and dreary out.  Even with the reduced light in the winter, the plants have done just fine and I’ve always gotten very nice growth out them.  Supplemental lighting would be just too expensive and the effort would just not be worth it.

If the sun was shining even on the coldest winter days, the inside would heat up so nice, all the way into the 80’s.  It was a joy to be out there then.  Snow sucked.  The glass was insulated enough where there was not much heat escaping to melt off the snow.  This made it even darker out there.  But as soon as the sun did shine, it wouldn’t take long and that snow would slide right off.  It was really nice working in shorts and t-shirt out there when it was zero outside with a foot of snow.

This year, I dropped my winter time temperature in the greenhouse down around 50-55 degrees.  This was to provide a natural dormancy period for many of the larger, more mature plants…such as my achachairu and madronos.  The cool period was also necessary for my longan and lychees.  The longan is much too large to be moving around anymore and I damn near killed them last year leaving them outside to get the proper chill period.  This also lowered the heating bill which made my wife happy.

What I Learned

• I would never do this again on my own.  Too much stress and too much time and effort away from things that should be more important.  While $17K is just stupid expensive, it might have been worth it.
•  I would never use any kind of wood in a project such as this.  100% recycled plastic lumber.  This is not a sunroom…nice and dry.  It is a high moisture environment.
• I would never attach a structure like this to my home.  Again, this is a high moisture environment and moisture WILL find its way into places where it is not welcome.
• If I could have afforded it, I would have built it bigger.
• It’s a bitch to clean inside and out.  Again, a high moisture area is going to make this more work.
• Insects…they can get the best of you and your plants.  Just try and keep even with them.

What I Grow

I’ve had some successes as well as plenty of failures as far as plants go.  The more experience you gain only means that you are willing to take more chances.  It’s always the really rare, never to be found again plants that seem to perish.  Those are low points and I’m usually not fit to be around.  But when even a small success rolls in, it pushes the failures a little farther back in the mind.

I unfortunately became hooked on the very rare and the very difficult to obtain tropical fruit trees.  It wasn’t enough to fruit mangos and bananas.  I had to go after mangosteen, longkong, rambutan, pulasan, and yes, eventually durian.  Once durian started to grow on me, I had to try and grow it.

If you want to try your hand at growing these types of plants, keep it simple and you will probably do just fine.  When you start trying to graft them, then you take a huge chance of losing the few plants you have.  You try once and then you can’t help but trying again.

Jay and his Tamarind Tree

I got to be pretty good at grafting but always lost out with durian.  Same with mangosteen, rambutan, pulasan, and longkong.  I took chances with plants like these back when I had no business doing so.  The result is many plants lost.  I would love to have some “do overs”.

I have had many successful fruitings.  I had dwarf Cavendish and Thai Namwah bananas fruit often.  These were all planted in the ground.  I eventually removed the Cavendish keeping only the Namwah.
Different mangos have fruited and I’m now working on a single cocktail mango tree with some superior varieties grafted on.  This was a very unproductive Nam Doc Mai mango tree…actually one of my very first mail order plants.

I had a huge mess of dragon fruit that gave us many delights from their blooms to their fruit.  These have since been removed and I now have better cultivars planted.

I have a cocktail cherimoya with several cultivars grafted on planted in the ground.  The fruit from the seedling portion has proven very tasty as well.  I just recently placed twenty-two more grafts on the tree and most of them have already pushed new growth.

I’m very much into the garcinias and have several types growing in one stage or another:  mangosteen, Imbe (g. livingstonei), lemondrop mangosteen (g. edulis), madruno (g. madrono), achachairu (g. spp. or some are calling g. laterifolia).  I had a lemondrop manogsteen fruit as well as the Imbe.  I currently have one male and one female planted in the ground.  The male produces tons of blooms whereas the female has been pretty shy unfortunately.  The madrunos and achachairu are also in the ground.

My Gold Nugget Jackfruit has finally started putting on fruit. This is another plant I was told would never fruit in Ohio.

Among some others are various citrus, grumichama, lemon guava, strawberry guava, papaya, sugar apples, longan, miracle fruit, starfruit, figs, wax jambu.  I had a kwai muk that had been putting out gobs of flowers.

Conclusion

We’ve had our moments with the greenhouse and not all of them good.  I have enjoyed it, and I spend a lot of time out there, hours at a time mostly.  Watering alone is time consuming.  Some of the larger and more desirable plants were planted directly into the ground.  I have a lot of plants so pruning is taken often necessary.  I’ve never once regretted building the greenhouse, just the choices I made when building it.  After all, building this greenhouse eventually led me to become close friends with many in this hobby.

So while my grand experiment with the greenhouse has not paid off with the mangosteens and a few other rare fruits, despite all the nay-sayers I did manage to create a little piece of Thailand here in central Ohio.

Summary

• Sunshine Rooms for building materials
• Southern Burner for heating 
• Bartlett Instruments for greenhouse thermostat
• Fogco for a fogger to control humidity 

Jay is a rare fruit enthusiast and hobbyist collecting and growing species from all over the world
and traveling to eat them!  He’s an active member of the Tropical Fruit Forum,  and author of the website Tropical Fruit Hunters.  He lives in Columbus, Ohio with his wife and two golden doodles.