http://www.plantgel.com/

A plant grown in synthetic mix should also carry less bacterials so must be more safe to send overseas.

The gel stuff breaks down rather quickly, releases neuro-toxic substances as it does, and (if used as the only medium for growing) does not provide air circulation around the roots.

See http://puyallup.wsu.edu/~linda%20chalker-scott/Horticultural%20Myths_files/Myths/Hydrogels.pdf

It may be OK for a short-lived houseplant being grown in a glass, but I would never grow a tree in it.

I'm curious, what plants did you use for this experiment? Are they still in the same mix? How long has it been? Thanks,

I've got some miracle fruit plants that have been in 100% Turface MVP for about 7 years now.  I have replaced at least 50% of the original mix during a couple of root-prunings; the pore space in the old mix was getting fairly full with degrading organic material (roots, leaves I didn't pick out, fruit that fell, etc.).  I've also grown/still have hibiscus, calatheas, pepper plants and more with similar results-- if you provide constant low level nutrients (basically hydroponic growing) it works great as a growing medium, but you'll still need to replace it over time because of all the other stuff that builds up in it.

   Kevin

You are an indoor gardening article, soon to be published!!!!!!!

Thanks Gary; I bet I may be written up sometime, though it may be just as likely in a psychology magazine as a gardening one...

   Kevin

One thing I have wondered about with indoor growing when you really devote an entire room to being a greenhouse, which is more than I have done as yet - do you see signs of damage to the house? Mold in the room or in your air ducts? Paint damage? Warping of floor boards?

The levels of humidity I'm running indoors would quickly destroy most any house.

I have purpose-built an airtight, watertight, rubber- and plastic-lined room with a sloping, self-draining floor and separate ventilation for growing plants.  It is the only way I can take care of so many plants, maintain the appropriate environmental conditions, and not destroy my house.  Inside the plant room is 75% humidity and 87 degrees right now, but the basement just outside the plant room is 30% humidity and 70 degrees.

   Kevin

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

Question about root pruning pots to grow garcinias in:
 Is the purpose to prune the roots because they don't like light and will grow back into the pot, in a denser form, or is it just easier to prune the roots with pruning sheers when they grow out of the slots in the side?  or none of the above?

Thanks!

Hello,

Root pruning pots cause the root tips to die as they approach the side of the pot, to force the roots to branch out further inside the pot.  They prevent circling roots and extra long roots and encourage a dense, bushy root system.

Pruning roots that come out the holes in the bottom of the pot will not do the same thing at all-- it will still allow the vast majority of the roots to circle, and will not encourage a bushy root system.

My Mexican Garcinias in fabric (root-pruning) pots are going nuts and have much better root systems and health than the ones in plastic pots.

    Kevin

OK, this is convincing me maybe my mangosteen would be better off indoors rather than leaving it to the elements, at least for the next few years until it gets (hopefully!) really big. Thus far it seems happy outside, but it's too early to tell if the current conditions would foster new growth.

My mangosteen was destined to be grown in a pot its entire life.  I forced it to adjust to that early on by forcing the tap root to self-prune at about only 8" long by placing it in a fabric pot.  I don't have any experience, but there's a lot of previous research and evidence that if you eventually want to plant your mangosteen in the ground, it should be done when it is 2 feet tall so that it can properly develop it's tap root.  Larger plants transplanted into the ground seem to fare poorly.

So unless you want to try to grow it in a pot its entire life, you may want to get it in the ground sooner rather than later.

CoPlantNut, could you tell me what "gritty mix" you use specifically? Truthfully, I'm hoping it's something that comes in a bag that I could easily order, not something I have to create myself - but even if it's complicated I'd like to know because I don't want to kill it just from soil in the transplant. I already have some Happy Frog organic soil and Espoma organic soil in bags, but I'm guessing those won't do. I also have sandy coral rock soil which is common to the Keys (which I guess is high in calcium, and probably also some salt!), and also high-acid dark soil from years of pine needles, but I doubt either of those is good enough either, probably even as part of a mix. Sorry, I am a total beginner when it comes to growing mangosteens, I don't have much experience growing plants that can't manage on regular soil.

Giving it the light, temperature, and humidity requirements would be easy for me here, as well as fresh rainwater, but I am clueless when it comes to soil.

The gritty mix I'm using is 50% pine bark fines, 50% Turface MVP.  It isn't available pre-packaged, but there's only 2 ingredients.  Because it is basically nutrient-free, I have to provide the plants with all their nutrients every time I water-- a drain-to-waste hydroponic setup.  Since I'm planning on keeping it potted its entire life, I want to force it to grow a good, fibrous root system so I only repot it into a slightly larger pot each time I need to, and I only repot it when it needs watering more than every 2nd day.  Between that and the hydroponic-like watering routine, I can generally get large, healthy plants to grow in fairly small pots for the long term, and so far it seems to be working for the mangosteen.

But again, by training it this way I think I'm forcing myself to always treat it this way-- I don't think it could be transplanted into the ground with great success.

I'm trying to put together a thread with pics of my mangosteen at various stages and a complete description of its treatment, but I've been incredibly busy; hopefully next week I can even get a current picture of it!

   Kevin

What sensors are you using?
How much light are you giving it for how long?
How are you keeping the humdity up?  Grow tent?

I'm using a variety of sensors; some are one-wire and some are I²C.  My setup is a custom-built 12'x15' plastic- and rubber-lined completely sealed room where I have 6 450W LED lights on a light mover and 4 135W LED lights not on a mover.  The photoperiod varies between 11.5 hours of light and 18 hours of light, though 80% of the time it is 16 hours/day of light.  Humidity is kept up through various evaporative humidifiers (1 on air intake, 1 40-gallon water tank with fans blowing over it, and the plants themselves-- mostly in fabric pots) and a backup ultrasonic humidifier.  You can get a better idea of my setup here: http://tropicalfruitforum.com/index.php?topic=8861.0

You look like your on your way to win the fruiting latitude award.

I still have many years to go before this thing is going to achieve fruiting size, but I'll certainly try!

Keven...very nicely done!  What you have there is probably the best chances you have at being successful.  If the nurser stocks continue to survive, you've given that plant a very nice root system to draw from.

Thanks Jay!  Some of the nurse stocks have died off after a year; some seem to be growing a little and fusing convincingly with the mangosteen, but as the mangosteen gets woodier my approach-graft take rates are going down.  The plant pictured above has at least 2 G. xanthochymus and 1 G. hombroniana nurse that seem to be doing well.

The plant looks fabulous.  You could always prune it back and let it start branching more but on the other hand...I think I would let it go for as long as accommodations allow.  Don't go trying to fix what ain't broke. 

My plan was to start tip-pruning it within the next couple growth flushes; I have a hard limit on height of about 5.5 feet unless I want to buy a new house, so I will need to constrain size.  It is growing so happily though that I'm dreading the thought; so far other Garcinias seem to take well to being treated as a bonsai so hopefully the mangosteen will as well.

I wish now that I had done something like this long ago instead of continuously trying to graft a mature plant onto the seedlings.  Some would take for a little while, flush, then crap out...leaving me with only a short stump of a plant.  So whatever you are currently doing, keep on doing it!

Based on your experiences and those of others, I haven't want to bother with trying to graft mature scions on.  The amusing thing is that I've tried getting over 50 mangosteen seeds from various forum members, and only ever had 1 germinate-- it got 1 inch tall and died.  All other Garcinia seeds I've received have done very well, just not mangosteen. 

   Kevin

CoPlantNut: That's impressive.  Can you go into more detail about rootstock grafting?  I'm not familiar.  Wow ... 6" to that ... What's your water routine?  Bottled or filter systems?

Multiple-rootstock grafting has been discussed on the forum before many times, but this topic has most of it: http://tropicalfruitforum.com/index.php?topic=109.0.  It is a way to get fruit trees to grow more compactly and vigorously while hopefully also making them more precocious.  In my experience so far, it works very well.

My tap water comes from a watershed on the continental divide and has very little in the way of dissolved solids (typically 50-80ppm) so I can get away with only an activated carbon filter to remove chlorine and fluoride.  I allow the water to reach growing-room temperature (75-80 degrees-- during the winter here it comes out of the tap at 40 degrees), then add fertilizer and adjust the pH to 5.7 before watering the plants with it.

   Kevin

Hello,

There is no perfect answer to your question; it really depends on a lot of things.

First, it depends on the kind of plant.  Some plants are very sensitive to the photoperiod and need a specific night-length to trigger specific responses such as flowering.  Many tropical plants aren't photoperiod-sensitive, but some certainly are-- some of my ultra-tropical orchids only initiate flower spikes when the night is longer than the day, though it doesn't take much (11.5 hours light, 12.5 hours dark).  If you're growing a whole bunch of different things, chances are some will be photoperiod-sensitive and some won't be.

Second, it depends on what you want your plants to do.  I can't think of any plant I've ever grown that didn't like growing at 18/6 or 20/4 schedules, but many would never bloom with those schedules.  If all you want is to get the plant to grow, more light is generally better.  Most plants will even grow happily with no dark period at all, though it has been my experience that they don't seem to grow any better than on a 20/4 schedule, so why pay for the extra electricity?  (Some plants will not be happy with continuous light; plants engaging in CAM photosynthesis http://en.wikipedia.org/wiki/Crassulacean_acid_metabolism only respire at night and will be unhappy with continuous light-- this includes pineapple.)

Third, it depends on your setup and conditions.  You can generally make up for less-intense artificial lights by increasing the time the lights are on each day.  As long as the plant still gets all the photons it needs each day, it can grow happily, though it may still grow differently than if it had more-intense light-- leaf size may be larger and the plant may be leggier than if the light was more intense.

Personally, I use a 18/6 cycle for most of the year for most of my plants, but drop it down to 11.5/12.5 for a couple weeks to get my orchids to bloom.  Pepper and tomato seedlings get 22/2 under a fairly intense light to maximize growth for the month they're being started inside.

I have noticed some issues moving photoperiod-sensitive plants between indoors and outdoors, but nothing catastrophic-- often it just triggers a second cycle of bloom, as if the plant had two fall periods in one year.

   Kevin

Interesting.  It just seems that seeds started in gritty mixes are not as vigorous as seeds started in peat mixes.

Gritty mix has very little in the way of nutrients; your experience with seedlings in gritty mix may be reflecting that.  Every time I water I use a dilute fertilizer solution-- essentially drain-to-waste hydroponics-- and seedlings started in the gritty mix seem more vigorous than those started in peat mixes for me.

   Kevin

I've fruited mangoes here at 5300 feet above sea level; elevation certainly isn't going to be the challenge for you.  If you can keep it warm enough and with enough light through the winter it is certainly possible to get them to fruit for you.

   Kevin

wow, a grapefruit.  Now that is a fruit that I really haven't found  away to like, which is crazy b/c I have liked almost all other citrus I have had.  Guess there's a black sheep in every family

Haskap (AKA honeyberries) berries change skin color and look ripe before they actually are fully ripe.  If they are eaten before they are fully ripe (still green inside) the flavor will taste grassy and like a bitter grapefruit.  When fully ripe (purple inside) the better varieties don't have any of the bitterness, but to me just have the aromatic notes of grapefruit and blueberries while being very sweet.  I suspect even if you don't like grapefruit that you might still like fully-ripe haskap berries.

   Kevin

Learning how to grow indoors is tricky and very different from growing outdoors.  Moving things inside for the winter and outside for summer is even trickier, as you're dealing with two completely different growing situations.  But don't let a few sick / dead plants get you down; we all learned to grow plants by killing a lot of them (I'm in the thousands, at least).  I've even lost 400+ several-year-old plants in one day about 10 years ago when my air conditioner failed and my grow room got up past 120 degrees...  Everything is a learning experience.

Oscar is also very correct when he points out that people tend to only notice the successes-- if you have many plants that are doing OK, most people don't notice the few sick ones.
 
Outgassing of plastics can be a problem, but I doubt it would cause the kind of issues you're seeing, especially after having your tent up for several months.  Ventilation will help in the long run, after everything has gotten over the shock of bare-rooting.

   Kevin