You've made good points concerning the lights. Between the neighbors being upset and your electric bill going thru the roof, I don't believe the light to be a good solution. Good for supplemental lighting and if it is inside an small enclosure, it will definitely raise the temps inside there during the day.

I don't think Christmas tree lights are going to it warm enough. You also have to consider how cold the soil is going to get. If the roots are cold, no amount of heat up above is going to help you out.

Keep the plant in a container for the time being. You have years and years...and years of time to provide yourself a solution to this problem! It will be a long long time before your plant is in a container large enough to complain about how heavy it is to move.

Don't forget about humidity.

I agree with Jay, keep it potted while you work out a solution. In regards to planting it, it will definitely require more care than the mango. Since the Mangosteen is and ultra-tropical plant, it will require special attention if they will be living outside a true tropical area. Care must be taken for proper soil, proper water ph (they like acid), winter protection and sunlight protection. One day that you forget about them, they can die. This means they will require daily attention especially in the winter. One option would be like you mentioned, creating a structure. Then prepare the structure with shade cloth for sunlight protection. These plants get little light when they are young in their tropical environment, since they are underneath the canopy of bigger plants around them. Then you have to prepare for the winter, some type of frost cloth (the frost cloth might be placed over the shade cloth and removed when danger of frost is gone) like this:

http://www.gintec-shade.com/frost_guard.html

Then you need to check the temperature inside the structure, if it still below 65, you would need to bring the temperature up. For example, a 120v Dayton heater:

http://www.littlegreenhouse.com/accessory/heaters3.shtml

Depending on the structure, you would need to check if the btu is enough. I am sure the other members can come up with other ideas for heat source.

Adiel

This is like raising a child. I love trailblazers, good luck Simon. I think the most difficult part of your plan is to keep the soil temp up during the winter. Everything above ground is doable. More the reason to keep it potted, pots can get pretty big, or u can build one yourself.h

I wish you luck. I also think the soil temp will be impossible to keep up and the low CA humidity will be really tough to overcome. I failed miserably in all of my attempts but hopefully you will have better luck. Best advice that I can think of is don't spend too much on the plants...

This is like raising a child. I love trailblazers, good luck Simon. I think the most difficult part of your plan is to keep the soil temp up during the winter. Everything above ground is doable. More the reason to keep it potted, pots can get pretty big, or u can build one yourself.h

Sorry for the dupe post. Must've hit some button twice on my phone.

Also, keep a few extra in pots as replacements because your main tree in the ground will probably die.

Wow, thanks for all the great advice and warnings. I'm absolutely Expecting failure but hoping for the best. I've neglected my small tiny little mangosteen for about two months and it looks exactly the same. I was seriously considering how I would keep the root zone warm during the cold winter but just clicked on the link that adiel posted and saw that there are some underground soil warming cables I can use.

I seriously considered growing my mangosteen in a super large, maybe #100 Smartpot and putting perhaps 2 x 4ft seedling heat mats under them but the underground cables look like they are more industrial strength. My seedling heat mats only raise the temp a little when it is very cold outside.

I was planning not to go with the giant container because I wanted the tap root to grow out very long. I wonder how the tap root will adapt to a smart pot that is supposed to air prune it and create finer capillary roots? Will a Smart Pot last 10+ years without falling apart?

Anyone have any info on how Bill Whitman established his tree? I think I remember reading he had a giant greenhouse and he brought in a fortune's worth of premium soil but anyone know the particulars? If I decide to grow in a large container, I want to try finding a large root, maybe the tap root and somehow connect it to a good size reservoir or RO water.

You guys brought up a good point about the humidity. If I use supplemental heat during the winter, it will dramatically decrease the humidity. If I add a humidifier, it may short circuit the heater or decrease the life of the heater. Whats do you think is the best and safest way to bring up the heat and humidity? I might be able to get away with a greenhouse heater and a humidifier set on very low.

What if I have 4-8 five gallon buckets filled with water inside the structure I build and don't use a humidifier? With the heater giving warmth, it will warm up the buckets of water which will evaporate slowly and just so slightly increase the humidity enough to possibly keep my plant healthy and not die.

I've considered extending my kitchen with an enclosed sunroom so that even in winter, it will only get to about 65F at the lowest since I have to turn on the heater for my baby daughter. This will cost a lot of money and that is why I wanted to build my own structure.

Anyone have links on grafting Mangosteens? I've also considered grafting two additional rootstocks onto a mangosteen essentially making a single tree with 3 sets of taproots. Is this feasable or am I just tropical fruit daydreaming? I was thinking I can do a side veneer graft that way neither the rootstock nor the main tree will die even if the graft didn't take. Please keep any suggestion or ideas coming no matter how crazy/imaginative it may be!
Simon

Assume that you can heat the ground with the cables, and also assume that the tree survives the winter and sends the taproot downward. How far down do you expect the taproot to go? Can you heat the earth at that depth? Possibly, since the ground below us is never as cold as the surface. I'm eager to see what you plan to do. I've been to some large, multi-level shopping malls where there are some real tall palm trees growing inside. Maybe you can plant a mangosteen in a tall container and leave it inside your house? If you have a 2-story house with vaulted ceiling.

Hi.
I'm trying to do the same with my mango. Since i live in central italy, i tink that growing a mango outside is out of question as much as is growing a mangosteen there where you live.
I'd like to join the post to share some ideas about what i tought in the last year tempting to solve the problem.
First: the soil temp. About 1-2 meters (3-6 feet) under the soil level the temperature is beginning to approach to average annual temperature of your location. This should be easy to know. Mine, for example, is 58,28F So, if you have a annual average temperature that allows mangosteen to grow (grow, not just survive) with just occasionals cold spell, there shouldn't be problems. If you don't, i guess the taproot will stop growing when it reaches the cooler soil. I'm not sure here, but i expect the roots in cold soild to be more rot sensitive, but is just a guess.
You shouldn't need to heat the soil if your annual average temperature is high enough because, after a summer, the structure should keep the soil under the mangosteen hotter than the rest of soil.
Second: the structure. In my city the winter are pretty long and cold (this year we got 15F, wrost winter in ten years, but not exceptional), but i manage to keep my greenhouse above 34F without additional heat just because i choosed the right spot to build it. It is attached to two concrete walls, one facing nord, the other facing east. Since, for me, cooler winds come from there it really saves a lot of heat during nights. I keep there mainly cactuses but last winter i overwintered mangoes there without any problem.
For the mango now i'm building a removable cover with same ideas in mind. I have built a north wall with concrete blocks filled with dirt (to increase their termical mass and help them retain solar heat). Then i'll build the north side of the roof with some rock wool panels. The north side will have the 45 degree inclinatin to keep it close to a sphere (the sphere minimizes surface/volume ratio, thus the dispersion) and because at this inclination, at my latitude, it starts to do a shade in the structure just after 21 march, when solar heat is not needed as before. The south wall instead will be in policarbonate, will have 30 degree of inclination (at this inclination sun will be perpendicular to the panel during the cooler days, in january). The principes are the same of a water heating solar panel.
To further help with it, i plan to put some drums filled with water inside that structure. During the day they absorb solar heat releasing it during nights. Water is better than rocks because has an higher termal mass. You can find a lot of ideas just googling "solar greenhouses": the idea is basically the same, the only difficult thing is to build it removable.
Third: the additional heat. The idea of heating water isn't bad, you just need an acquarius heater. Surely it won't be bothered from humidity. I'm not going with it anyway, because i'm going to imagine that i'll need heat just in few specific hours: and waters takes a bit in heating and, when is heated to the point to quickly transport heat to air, takes a lot to cool down. Plus i'd like to consume as little energy as possible. I guess there are some calculation here to take, but to make it simple i have two suggestion. First idea: incadescence light bulb in series: if you put two of them one after another you'll have less light but they will put out a lot of infrared, wich is what you need. Second idea: there are some lamps just for heating chicks. No light, just heat. Put just a thermostat to turn them on when needed, and this should hopefully keep the tree heated.
Just few ideas to add to the talk. I'm a total newbie, and, in the end, i do all this just for fun.
I'm sorry for any mispell, english is not my laguage.

Daring plan you have there Simon. Here is an article I found on highly successful wedge grafting of tropicals in pdf format:

Here is a link that might be useful: Wedge grafting tropicals

Pancrazio, I really like your ideas. And, I think you are on the right track. Please let us know in the future how it works out and also if you can post a picture of what you have so far, that would be great!

newgen, that is a very good option: keeping it inside. Also, if you had a vaulted ceiling terrace, you can actually plant the tree in the ground inside your home! :)

Simon, Bill took out the limerock because it was high in PH and replaced it with sandy loam soil with lower PH. He had alot of money to do his entire property. I believe it was around 600 truckloads of soil he replaced. He also had the advantage that at bal-harbour the temperatures are higher compared to more inland areas. He created structures made of 60% shadecloth to surround the tree and protect it from sunlight.

Adiel

Honestly I think your plan with the sunroom off of your kitchen is the only idea that has any shot at all of success but even then it would still be quite a challenge.

Hey newgen, I don't expect to heat the entire rhizosphere, just a portion of it to keep it happy, I will likely use a 100gallon smart pot and try to heat only this container. I will try to find any good root and cut a small opening in the smartpot and try to give the mangosteen a permanent source of water since I read they like to be by lakes or ponds or the underground water table.

Pancrazio, those are some great suggestions you have and I hope you will be able to fruit some mango over there. Mango won't be as sensitive to the cold and will be easier because you don't have to worry about giving it humidity, in fact, depending on the race, they probably hate the humidity.

I live in a special microclimate here in San Diego and Manilla type mangoes don't even need frost protection in winter. It rarely gets below 45F but we do get several nights of frost a year in bad years and there have been stretches of several years where we get no frost.

I used to breed large fish called FlowerHorns so I know how expensive heating water is. Heating 6 x 60 gallon tanks inside an unheated house in winter, indoor temp about 60-65F can costs several hundred dollars a month using 300Watt black plastic Eclipse water heaters in each tank. It depends what temp you set it at but it is expensive none the less. I like the eclipse water heaters because they won't shatter like the cheaper glass ones.

north tree man, good to see you again and thanks for the link! I hope all your lychee trees are doing well. I finally planted most my lychees into the ground and they seem 100 times happier than the pots they were in. My Sweetheart was rootbound bad since I left it in the same pot for I think 2-3 years! I had to pull apart a lot of its roots but it is much happier now. If you don't up pot your plants bi-annually or anually, you should look into breathable pots. They are supposed to air prune the roots, discouraging plants from becoming root bound.

adiel, thanks for the information! My house is only single story but I have considered planting my mangosteen directly in the ground of my house if I do decide to purchase an indoor sunroom. If I build a structure or purchase a small greenhouse for my mangosteen, I will definitely put up 60% shade cloth for the first 5-10 years. I plan on purchasing lots of good quality organic potting soil and using this in the smartpot. I won't need tons of material like Bill because this single tree is my main focus.

OK, here is a serious question for anyone reading this post: how is your Mangosteen doing? I can't be the only one trying to kill a mangosteen at this time on this forum. I have a feeling there are some top secret mangosteen growers that have nice looking plants but they don't want to post pics until their plants actually fruit.

I visited a Dragonfruit farm near I think Fallbrook and inside the greenhouse, they had lots of mangosteen plants inside that looked very nice. Fallbrook is only about 45minutes to 1 hours from where I live in San Diego. It was about 2 years ago and the plants were about 4 feet tall and looked almost identical to eggo's Mangosteen except the farms appeared to be larger. By now, the plants must be 5-7feet tall, I have no idea how fast they grow.

If you have any pics or info on how you grew your Mangosteen, please share with us here. Anyone personally know eggo? I sent him an email but never got a reply. He's had one of the best looking plants aside from the farm that I have seen. PLease keep your thoughts and ideas coming!
Simon