Growing Mangosteen in greenhouse in SoCal

[Kuhyay]

For the past few years I've flirted with the idea of trying to fruit G. Mangostana in-ground here in San Diego 10a. (Vista/Bonsall area). While all my other garcinias have done well unprotected, I think it would be exceedingly difficult, if not impossible, to achieve the right conditions over the necessary 20-year period outdoors for mangosteen.

Here are the challenges I see:

• They need major cold protection. We get rare overnight colds snaps that dip as low as 30F, with average lows in the low 40Fs.
• They need heat protection. We get occasional heat waves that go as high as 107F, with average highs in the 80Fs/90Fs.
• They need humidity control. We get annual Santa Ana winds that drop RH below 10%.

Luckily, we are planning to install a large permanent greenhouse on our new property where, given the right systems, I hope we should be able to mitigate the worst of our climate's limitations for this ultra tropical white elephant.

Am I considering the right constraints? If so, does anyone have experience creating this type of environment in a greenhouse in SoCal? Specifically:

• Heating system to maintain winter lows above 55F
• Cooling system to limit summer highs to 90F
• Humidity control system maintain keep an average RH of ~80%

Some specifics about the property where greenhouse will be located:

• Zone 10a, sunset 23
• Mostly E aspect, with some NW
• Gently sloping, downhill. Neighbors with same topography report light frost every 6 years or so.
• Well draining, fine sandy loam, neutral ph
• Gets cool daily breeze from the Pacific Ocean through the San Luis Rey River basin.

[brian]

I'm pretty much doing exactly what you describe.  My mangosteen has barely grown at all since I got it a year or two ago, like only a few inches.  I think I injured it with a foliar spray at some point though so I got a couple more I scattered around my greenhouse to see if it is just a fluke or not.  The other garcinias I got at the same time have been quite healthy.

Try it! 

[fruitnut1944]

It's easy to maintain 55 extreme low in that area. It's easy here when it drops to zero. I'd suggest two heaters both capable of holding 55 when it's the colest ever outside. One heater as backup just in case.

Holding 90F when 107 outside isn't as easy but can be done with large exhaust fans and a wet wall. It might take some shade as well. The right greenhouse covering will limit heat loss in winter and heat gain in summer. My GH has double layer inflated woven poly and is easy to cool. Palring 175UV over 146UV.

The hard part is the 80% RH. What I'd look into is a misting system.

Also you want something as backup in case the power goes out. A few hrs without power could ruin yrs of work.

It would help to know your light level requirement. Mine with the double layer is about 50% of outside which is more than enough for the dozens of kinds of fruit I've grown.

[Finca La Isla]

Sounds interesting.
You might not need the humidity so high but 80% should be good.
While support at 55f is what you hear I wonder if the tree would continue to grow well at that temp.  If not then the roots could become vulnerable to fungus.  Our trees grow well through the entire year but our absolute minimum temperature is 20C, (68f).
Our soil is a clay loam with a ph of 6.1. Where I’ve done farm stays in Malaysia the conditions were very similar and soil at 6.5
Suerte
Peter

[Mike T]

I think getting the seeds from the most precocious stock possible would increase your chances. I don't know if there is much variation in cold tolerance in mangosteens as a whole.

[jtnguyen333]

Another tropical fruit to try to grow if you have a greenhose is star apple aka breast milk fruit if you translate it from Vietnamese.  Growing up in Vietnam..I like it more than mangosteen because it is more readily available and cheaper .

[fruitlovers]

Having lived in southern California for a couple of decades, and growing mangosteens now in Hawaii i can tell you from experience that the main difficulties in growing mangosteen in your area is maintaining high humidity all year long. This could be done with misters. But you don't want to use city water with chlorine, salts, or high pH. You need rain water or a very good water filtration system. Also mangosteens, and other "ultra" tropical fruits, like very little variation between night time temperatures and day time temperatures. It's not enough to keep temperature from dropping below 55F, and then during the day you reach 100F. Mangosteens can easily withstand 100F when there is high humidity. But they can't stand that variation of 50+ degrees difference between night time and day time temperatures. You don't want the temperatures to vary more than 20 degrees. You may be able to get the tree to grow with higher variation, but it will be very difficult to get it to fruit with higher temperature variations. If possible, i would also use a heating coil in the soil to keep soil temperatures from dropping around the roots system below 70F. Also in winter when the days shorten you will need a good lighting system to lengthen amount of hours of light the plants receive. Good luck. Nobody has been succesful yet at growing mangosteen in California, but i think it is doable given enough perseverance and attention to detail.

[Mike T]

Yes humidity is what they enjoy and as Oscar pointed out they don't like high temps regardless of humidity. Over 100f and leaves of big trees scorch. They are not fans of prolonged periods where days are over say 95f. I had a run of days over 110c a couple of years ago and it scorched the heck out of my trees without any dry wind.

[bsbullie]

Yes humidity is what they enjoy and as Oscar pointed out they don't like high temps regardless of humidity. Over 100f and leaves of big trees scorch. They are not fans of prolonged periods where days are over say 95f. I had a run of days over 110c a couple of years ago and it scorched the heck out of my trees without any dry wind.

110c?  Is that a typo?

[Elopez2027@aol.com]

Kuhyay,

I love Mangosteens. You seem to have perfect ‘everything’ for them. Go for it, just Don’t forget the minerals. Searching thru the past files here, which I recommend, I discovered a thread of calcium and mangosteen. How important that mineral is for it. How it helps the growth. So, recycle those egg shells and place them around the roots for health and growth.

[Kuhyay]

Having lived in southern California for a couple of decades, and growing mangosteens now in Hawaii i can tell you from experience that the main difficulties in growing mangosteen in your area is maintaining high humidity all year long. This could be done with misters. But you don't want to use city water with chlorine, salts, or high pH. You need rain water or a very good water filtration system. Also mangosteens, and other "ultra" tropical fruits, like very little variation between night time temperatures and day time temperatures. It's not enough to keep temperature from dropping below 55F, and then during the day you reach 100F. Mangosteens can easily withstand 100F when there is high humidity. But they can't stand that variation of 50+ degrees difference between night time and day time temperatures. You don't want the temperatures to vary more than 20 degrees. You may be able to get the tree to grow with higher variation, but it will be very difficult to get it to fruit with higher temperature variations. If possible, i would also use a heating coil in the soil to keep soil temperatures from dropping around the roots system below 70F. Also in winter when the days shorten you will need a good lighting system to lengthen amount of hours of light the plants receive. Good luck. Nobody has been successful yet at growing mangosteen in California, but i think it is doable given enough perseverance and attention to detail.

Oscar, You bring up a great point about soil temperature. From what I understand surface soil in SD ranges from ~60F during our coldest days to ~80F during our hottest days. It seems providing some root heat during the winter would keep things moving along. Would you recommend localized heating around the tree, or some type of full-greenhouse soil heating system?

I'm thinking that a well placed tank/pond could serve double duty here. Both providing humidity as well as a thermal mass to regulate fluctuation. What are your thoughts?

Sounds interesting.
You might not need the humidity so high but 80% should be good.
While support at 55f is what you hear I wonder if the tree would continue to grow well at that temp.  If not then the roots could become vulnerable to fungus.  Our trees grow well through the entire year but our absolute minimum temperature is 20C, (68f).
Our soil is a clay loam with a ph of 6.1. Where I’ve done farm stays in Malaysia the conditions were very similar and soil at 6.5
Suerte
Peter

Ph is a great callout Peter. Our native soil is pretty neutral, but water is definitely alkaline at ~8.2-8.6. I suppose that can be mitigated by building a deep organic layer with regular amendments of sulfur.

It's easy to maintain 55 extreme low in that area. It's easy here when it drops to zero. I'd suggest two heaters both capable of holding 55 when it's the colest ever outside. One heater as backup just in case.

Holding 90F when 107 outside isn't as easy but can be done with large exhaust fans and a wet wall. It might take some shade as well. The right greenhouse covering will limit heat loss in winter and heat gain in summer. My GH has double layer inflated woven poly and is easy to cool. Palring 175UV over 146UV.

The hard part is the 80% RH. What I'd look into is a misting system.

Also you want something as backup in case the power goes out. A few hrs without power could ruin yrs of work.

It would help to know your light level requirement. Mine with the double layer is about 50% of outside which is more than enough for the dozens of kinds of fruit I've grown.

Good point on light fruitnut1944. I'm thinking since Mangosteen is an understory tree, it could fruit with less than full light. Though I would love some input from actual growers! Having a double layer would help with temperature regulation and also cut down the need for additional shading. Regarding redundancy, that is a great point as well. We do get occasional power outages are during the wildfire season.

[K-Rimes]

PH is a huge issue in California and it's been the most effective thing I've changed in all my plants. The heavy calcium is also an issue in most water systems, especially so in wells like I'm on.

It is a big challenge to pull off what you're talking about - but I respect the hustle. My greenhouse in 9b has been pretty effective, but alone it's not enough to push much past one zone. If you have a heavily insulated greenhouse, that's going to be helpful all around. My gh has no insulation properties and is only good for about 10f of protection - which is plenty for what I'm pushing. I only needed a heater on one 26f night and it kept the GH at 37f all night.

As others have noted, you need layers of fall back plans - I bought a 6kw diesel generator for my house, well, grow lights, and fans. It has almost 200 hours of use since the power goes out so often up here on the mountain pass. I deeply recommend it having seen what happened in Texas.

It will be very costly in $ to heat, water to spray, and stress to manage. Personally, I've backed off on really pushing past my zone because of how involved it is - but if you have the time, money, patience and space I applaud you. I just buy mangosteens, mangoes, and ultra tropicals at the store when they're in season and that suffices for me.

Keep the forum updated though, it will be really cool when it's all dialed in. Check out Mark from Texas greenhouse set-ups, he probably has the most well built and sorted stuff I've seen with misters, fans, heaters, and so on.

[brian]

My greenhouse is heated and cooled (fog/misters) and well insulated, but I get 40F temperature swings all the time.  Any sunny winter day will be ~90F and then ~55F at night.  Humidity seems high, though I don't have a gauge. 

[Finca La Isla]

We don’t consider mangosteen to be an understory tree.  Mangosteens in Malaysia are grown in full sun.  Our practice is to use shade until they reach 6’ then start removing the shade.  They’ll fruit in the shade but it will take longer and there will be less harvest.
I think the idea of a pool of water is a good one.
So many details...
Peter

[Mike T]

I agree full sun once they are 6 or 7 ft. They get big and when you see a 70ft to 80 ft tree its hard to recognise as a mangosteen.

[canito 17]

Hi
Many years ago I saw a video from Canada. A guy have a very expensive green house. He use a hot tub system for temp and humidity. Here in the tropics agronomyst from Colegio de Mayaguez, developed a system to lower temperature in a green house.
But you can use some chemicals to force a high chill species to bear fruits in Puerto Rico.

[fruitlovers]

Having lived in southern California for a couple of decades, and growing mangosteens now in Hawaii i can tell you from experience that the main difficulties in growing mangosteen in your area is maintaining high humidity all year long. This could be done with misters. But you don't want to use city water with chlorine, salts, or high pH. You need rain water or a very good water filtration system. Also mangosteens, and other "ultra" tropical fruits, like very little variation between night time temperatures and day time temperatures. It's not enough to keep temperature from dropping below 55F, and then during the day you reach 100F. Mangosteens can easily withstand 100F when there is high humidity. But they can't stand that variation of 50+ degrees difference between night time and day time temperatures. You don't want the temperatures to vary more than 20 degrees. You may be able to get the tree to grow with higher variation, but it will be very difficult to get it to fruit with higher temperature variations. If possible, i would also use a heating coil in the soil to keep soil temperatures from dropping around the roots system below 70F. Also in winter when the days shorten you will need a good lighting system to lengthen amount of hours of light the plants receive. Good luck. Nobody has been successful yet at growing mangosteen in California, but i think it is doable given enough perseverance and attention to detail.

Oscar, You bring up a great point about soil temperature. From what I understand surface soil in SD ranges from ~60F during our coldest days to ~80F during our hottest days. It seems providing some root heat during the winter would keep things moving along. Would you recommend localized heating around the tree, or some type of full-greenhouse soil heating system?

I'm thinking that a well placed tank/pond could serve double duty here. Both providing humidity as well as a thermal mass to regulate fluctuation. What are your thoughts?

Sounds interesting.
You might not need the humidity so high but 80% should be good.
While support at 55f is what you hear I wonder if the tree would continue to grow well at that temp.  If not then the roots could become vulnerable to fungus.  Our trees grow well through the entire year but our absolute minimum temperature is 20C, (68f).
Our soil is a clay loam with a ph of 6.1. Where I’ve done farm stays in Malaysia the conditions were very similar and soil at 6.5
Suerte
Peter

Ph is a great callout Peter. Our native soil is pretty neutral, but water is definitely alkaline at ~8.2-8.6. I suppose that can be mitigated by building a deep organic layer with regular amendments of sulfur.

It's easy to maintain 55 extreme low in that area. It's easy here when it drops to zero. I'd suggest two heaters both capable of holding 55 when it's the colest ever outside. One heater as backup just in case.

Holding 90F when 107 outside isn't as easy but can be done with large exhaust fans and a wet wall. It might take some shade as well. The right greenhouse covering will limit heat loss in winter and heat gain in summer. My GH has double layer inflated woven poly and is easy to cool. Palring 175UV over 146UV.

The hard part is the 80% RH. What I'd look into is a misting system.

Also you want something as backup in case the power goes out. A few hrs without power could ruin yrs of work.

It would help to know your light level requirement. Mine with the double layer is about 50% of outside which is more than enough for the dozens of kinds of fruit I've grown.

Good point on light fruitnut1944. I'm thinking since Mangosteen is an understory tree, it could fruit with less than full light. Though I would love some input from actual growers! Having a double layer would help with temperature regulation and also cut down the need for additional shading. Regarding redundancy, that is a great point as well. We do get occasional power outages are during the wildfire season.

I never tried heating soil when i lived in California. But i would think that heating all the soil would be too expensive and too difficult. The area around root ball would a heated wire coil would be sufficient, or warm water pipes. Would have to be extended as the plants grow.
The water pH can be acifidified simply by adding vinegar to holding tank.
Mangosteens are not understory plant, although the need filtered sun when the are smaller than 4 feet tall. After that can transition to full sun. In desert areas though where sun gets really intense, say during Santana condisitons, would be good to have some 30% shade cloth over them.
A pond would help a lot to trick the plants into thinking they are in humid tropics. They also help to stabilize air temperatures.

[cassowary]

Having lived in southern California for a couple of decades, and growing mangosteens now in Hawaii i can tell you from experience that the main difficulties in growing mangosteen in your area is maintaining high humidity all year long. This could be done with misters. But you don't want to use city water with chlorine, salts, or high pH. You need rain water or a very good water filtration system. Also mangosteens, and other "ultra" tropical fruits, like very little variation between night time temperatures and day time temperatures. It's not enough to keep temperature from dropping below 55F, and then during the day you reach 100F. Mangosteens can easily withstand 100F when there is high humidity. But they can't stand that variation of 50+ degrees difference between night time and day time temperatures. You don't want the temperatures to vary more than 20 degrees. You may be able to get the tree to grow with higher variation, but it will be very difficult to get it to fruit with higher temperature variations. If possible, i would also use a heating coil in the soil to keep soil temperatures from dropping around the roots system below 70F. Also in winter when the days shorten you will need a good lighting system to lengthen amount of hours of light the plants receive. Good luck. Nobody has been successful yet at growing mangosteen in California, but i think it is doable given enough perseverance and attention to detail.

Oscar, You bring up a great point about soil temperature. From what I understand surface soil in SD ranges from ~60F during our coldest days to ~80F during our hottest days. It seems providing some root heat during the winter would keep things moving along. Would you recommend localized heating around the tree, or some type of full-greenhouse soil heating system?

I'm thinking that a well placed tank/pond could serve double duty here. Both providing humidity as well as a thermal mass to regulate fluctuation. What are your thoughts?

Sounds interesting.
You might not need the humidity so high but 80% should be good.
While support at 55f is what you hear I wonder if the tree would continue to grow well at that temp.  If not then the roots could become vulnerable to fungus.  Our trees grow well through the entire year but our absolute minimum temperature is 20C, (68f).
Our soil is a clay loam with a ph of 6.1. Where I’ve done farm stays in Malaysia the conditions were very similar and soil at 6.5
Suerte
Peter

Ph is a great callout Peter. Our native soil is pretty neutral, but water is definitely alkaline at ~8.2-8.6. I suppose that can be mitigated by building a deep organic layer with regular amendments of sulfur.

It's easy to maintain 55 extreme low in that area. It's easy here when it drops to zero. I'd suggest two heaters both capable of holding 55 when it's the colest ever outside. One heater as backup just in case.

Holding 90F when 107 outside isn't as easy but can be done with large exhaust fans and a wet wall. It might take some shade as well. The right greenhouse covering will limit heat loss in winter and heat gain in summer. My GH has double layer inflated woven poly and is easy to cool. Palring 175UV over 146UV.

The hard part is the 80% RH. What I'd look into is a misting system.

Also you want something as backup in case the power goes out. A few hrs without power could ruin yrs of work.

It would help to know your light level requirement. Mine with the double layer is about 50% of outside which is more than enough for the dozens of kinds of fruit I've grown.

Good point on light fruitnut1944. I'm thinking since Mangosteen is an understory tree, it could fruit with less than full light. Though I would love some input from actual growers! Having a double layer would help with temperature regulation and also cut down the need for additional shading. Regarding redundancy, that is a great point as well. We do get occasional power outages are during the wildfire season.

I never tried heating soil when i lived in California. But i would think that heating all the soil would be too expensive and too difficult. The area around root ball would a heated wire coil would be sufficient, or warm water pipes. Would have to be extended as the plants grow.
The water pH can be acifidified simply by adding vinegar to holding tank.
Mangosteens are not understory plant, although the need filtered sun when the are smaller than 4 feet tall. After that can transition to full sun. In desert areas though where sun gets really intense, say during Santana condisitons, would be good to have some 30% shade cloth over them.
A pond would help a lot to trick the plants into thinking they are in humid tropics. They also help to stabilize air temperatures.

In my obsvervation g. mangostana is a understory plant species. The growth of g. mangostana reveals it's an understory tree, canopy tree's in forests where g. mangostana could have originated from, grow a lot taller then g. m. so it would have mostly excusivly been under other tree's canopy. And g. m. fruits under the canopy of other tree's. One mangosteen farmer told me personally that the biggest and best fruits are located where g. m. branches meet or where there's tall tree's above, like durio sp. etc. Same farmer also showed me some tree's that where severely burnt during the sun intense months here in fnq, with the consequense of poor yeilds for up to two years, (not due to poor irrigation and it does not happen every year). Sap proliferation inside the fruits was also lower in shaded g. m. fruits. Many rainforest tree's favour being nursed under the shade of other tree's and that can be seen in g.m. too.

I am not saying you can't "cultivate" g. m. in full sun and receive high and quality yeilds, it's being done but that to me and other observations does not support the notion it's a canopy tree or forest edge tree so more likely understory tree.

[Finca La Isla]

I planted out 30mangosteen trees more than 30 years ago at 10m spacing.  Turns out that they’re planted too close and the branches cross big time.  I’ve actually eliminated 5 of these large mangosteen trees so that more light could enter.  Where there’s shade they don’t produce the same.  Looking at the sides of the trees where the sun hits they look great, lots of wonderful foliage and plenty of fruit.  When you walk into the grove where the branches are crossing there’s not much.  So we took some out so that the sun gets in there.
I guess it depends on your conditions but here, in the wet equatorial zone, mangosteen grows huge and wants full sun to produce at its potential.  I once read in an Australian blog about mangosteen leaves getting dry like crisps.  We don’t see that and I don’t think they do in Malaysia either.
Peter

[fruitlovers]

I have same experience as Peter. Mangosteen trees do get large, just takes a very long time for them to reach full size. And they need full sun for maximum fruit production. The tree will survive with some shade, but will not produce as well when shaded.

[LycheeLust]

I am growing mangosteen unprotected as of 2 months ago in Oxnard. It was unfazed by 40F at night but the top leaves were burnt by the sun. It’s a 2-3 foot seedling

[fruitlovers]

I am growing mangosteen unprotected as of 2 months ago in Oxnard. It was unfazed by 40F at night but the top leaves were burnt by the sun. It’s a 2-3 foot seedling

Don't let the leaves get burned. This will stunt the plant. Also temperatures below 50F stunt the plant.

[spaugh]

Kenny, You should try growing something like a mango tree in a GH and see how that goes first.  Its harder than you think and more costly to try and keep things within target temperature and humidity bounds.  Of course with enough money we can launch things into space and grow any plant where it doesnt belong.  That doesnt mean its a wise use of money.  Not to be negative, just trying be honest.  I can tell you straight away you are looking at mega bucks to do what you are talking about.

[fruitlovers]

Kenny, You should try growing something like a mango tree in a GH and see how that goes first.  Its harder than you think and more costly to try and keep things within target temperature and humidity bounds.  Of course with enough money we can launch things into space and grow any plant where it doesnt belong.  That doesnt mean its a wise use of money.  Not to be negative, just trying be honest.  I can tell you straight away you are looking at mega bucks to do what you are talking about.

I think that's very good advice. Also i think it's very wise to start with the easier ones and work your way towards the harder ones to grow. You learn as you go along.

[FV Fruit Freak]

I am growing mangosteen unprotected as of 2 months ago in Oxnard. It was unfazed by 40F at night but the top leaves were burnt by the sun. It’s a 2-3 foot seedling
[/quote
You’re wasting your water, and time... it will eventually die a slow death...They WONT grow in Cali, period. Props for trying though.