When I was 3, I started planting seeds from tropical fruit because I wanted to see what the plants looked like. I had no local examples in Colorado of things like citrus and avocado trees. Any time I saw a new fruit available in the grocery store, I wanted to get one to see what it tasted like-- and what the plant looked like. Over time my obsession changed to growing things that were simply not available in any store in my area-- at least not in decent condition.
My obsession has continued for several decades and I recently decided to try a Mangosteen (Garcinia mangostana). It seemed like a particularly fun, if idiotic challenge to try and grow here. They're slow, picky and notoriously challenging to grow, at least here in the continental US.
On top of that, for it to work in my available climate-controlled conditions, I would have to keep the plant in a pot its entire life and at most 5 feet tall. I'm still a long way from fruit, but I'm a little surprised with how well it seems to be going so far.
At the end of March 2012 (2+ years ago) I received 2 Mangosteen and 2 Achachairu plants from Montoso Gardens in Puerto Rico, in quart sleeves. I was amazed with the quality of the plants and packing-- and I got lucky that it didn't suddenly turn cold here while they were in transit.
After a week to ensure they weren't going into shock from shipping, I mostly bare-rooted the plants (there weren't many roots except the tap root) and transplanted them into a mix of 50% pine bark fines and 50% Turface MVP in 1-gallon pots. For the entire time I've had them, they've been getting watered as-needed (typically every 2-3 days) with filtered tap water (fluoride and chlorine removed) with 2.25ml of DynaGro Grow per gallon of water, adjusted to pH 5.6-5.8 with phosphoric acid.
To run a side-by-side test to see if fabric pots or a taller plastic pot would work better, I put one mangosteen and achachairu in each type of pot. Here are three of the plants April 3, 2012 after transplanting. The largest Achachairu I received is on the left, I still have the mangosteen (I'll call it #1) in the middle, the mangosteen on the right (I'll call it #2) was sent to Florida almost a year ago-- I needed more room.
To start, I had them under 1800W of HID lights (1 1000W metal halide, 2 400W CMH [ceramic metal halide]). They did OK, though the leaves showed some signs of stress (like most plants under HID lights); here they are June 10, 2012 (2 months after repotting, after their first growth flush):
Shortly thereafter I got another 2-gallon mangosteen seedling from Ethan in California (I'll call it #3), shown here on the left before repotting, May 10 2012:
This too promptly was bare-rooted and put into a 1-gallon fabric pot with gritty mix. I decided to try it outdoors over the summer, and while it didn't die, it clearly wasn't nearly as happy and is just now (18 months later) starting to fully recover from the lack of humidity, large temperature swings and frequent wind. I'm fairly certain mangosteen aren't happy outdoors here even during the summer.
I planted a couple G. xanthochymus and G. hombroniana seeds in the pots July 2012, and in October 2012 I started approach-grafting these seedlings on as extra rootstocks for the mangosteens. In November 2012 I switched the lights to 4x 450W Black Dog LED lights and 2X 400W CMH bulbs; by January 2013 I had ditched the CMH bulbs and was running only 6X 450W Black Dog LED lights.
The mangosteen seemed happy with the changes- here they are May 19, 2013:
Mangosteen #2 is on the left, #1 in the middle, and #3 on the right (just starting to recover from 3 months of exposure to a Colorado summer after 9 months in the plant room again).
Here's a close-up of #1's first pair of approach grafts, xanthochymus on the left and hombroniana on the right:
And here's #1 in its normal spot in my plant room, also 5/19/2013:
I'd read that mangosteen liked shade when small, so I put the plants under others and let them grow up through the canopy of the other plants to get more light-- it seems to have worked rather well.
Here's #1 on July 12, 2013 in it's normal spot in the plant room, sending out its first side-branches (bottom of the picture):
This photo from 1 month later (August 3, 2013) shows how fast it has started growing-- #1 is on the left, #2 in the middle, #3 on the right:
Granted it is a sample size of only 1, but #1 in the fabric pot seems to be much happier after 16 months in a fabric pot than #2 in the plastic pot, despite always having identical growing conditions. (I can show the same with Garcinia sp. achachairu, Garcinia intermedia, Luc's Mexican Garcinia and many other plants-- the root-pruning fabric pots seem to grow much happier, healthier, more compact plants in my conditions.)
Mangosteen #2 got shipped to Florida at this point, and #1 got repotted into a 3-gallon fabric pot. I added more G. xanthochymus and G. hombroniana nursing rootstocks to both #1 and #3 at this time as well.
Here's #1 on December 17, 2013 in its normal position in the plant room:
#3 got transplanted into a 3 gallon fabric pot around this time as it finally sent out its first branches.
Here's #1 after some more multiple-rootstock grafting work on January 20, 2014:
And here's #1 again April 26, 2014, after I've had it for 2 years:
(there is some extra G. xanthochymus and G. hombroniana foliage at the bottom-- future extra rootstocks).
Just for fun, here's a picture comparing the mangosteen to the achachairu from the first picture in my post, 2 years later:
(That's a Eugenia reinwardtiana on the left; it had to come out of the plant room to let the mangosteen and achachairu out.)
So far my largest mangosteen (#1) seems happy still in a 3-gallon pot; my general rule of thumb is to never give a plant a larger pot unless it is required-- defined as needing water more often than I'm willing / able to provide it. Until this plant dries out more than every 2 days, it will stay in this 3-gallon fabric pot.
Environmental conditions for #1 have been the same (except for the switch to LED light in November 2012) for the entire time I've had it: 70-72 degrees minimum at night, 88 degrees during the day, 70% minimum humidity, 100% humidity every night (condensation forms on the ceiling and walls of my plant room, but not on the plants). The photoperiod is 14-18 hours per day, aside from a few weeks a year I drop it to 11.5 hours (this is done to trigger my orchids to bloom, not for the mangosteen).
So far the mangosteens have been easier to grow and faster-growing than I expected; hopefully I'll be able to keep it alive long enough to get it to bloom-- I'm hoping that dwarfing it in a fabric pot, giving it extra rootstocks, and providing it with ideal environmental conditions may prod it into blooming young, but I'm sure I still have several years to wait.
Kevin