Agreed watering can be tricky. Proper watering techniques, and a good eye on the plant itself helps.
Good point about the dowel passing through the top soil first. I would imagine that if you are good about doing a proper watering(ie a good soak rather then just sprinkling a little water on top) you will always dry out from the top down in which case the dowel will help. I have also seen a stick with notches taken out every 1 or 2" on the side. You insert the stick all the way down and pull it out. Where the soil is still wet, it will come out with the stick in one of the notches. Where the notches have no soil in them, the soil is dry. This works better with finer soil which isn't the case when using straight gritty mix.

-Luke

Good point to stress.  You need to get a sense of how much water your soil holds.  Wait until dry, water it, wait a bit to see if any drains, water more, wait a bit to see if it drains, etc, until water starts coming out the drainage holes.  That's how much your soil holds.  Now when you water, water just a little bit less than that amount.  Retest at regular intervals because it can change a little or your initial estimate could be off.  Also, watering enough that a bit of water drains is good every now and then because you wash out any excess minerals that have built up that you might not want (sodium being the main culprit).  Don't do it too often though or you'll just be washing out your ferts.

If you don't get a sense of how much your soil holds and you water too little, the bottom of the pot will stay dry at all times even while the top could be very wet.  Which obviously isn't a good thing.  My 7 gallons take roughly one and a half "watering cans" of water.  My 15s take roughly one "bucket".  Etc.

Size depends on the size of the tree.  Soil type, gritty mix (that is, include some sand and gravel).  Mangos are prone to root rot so the worst thing is having their roots sit around in damp organic matter 24/7.  Let the soil dry out between waterings.  A well-ventilated pot is important; I wouldn't just use one with just one tiny drainage hole on the bottom.  Clay breathes bettter than plastic, but plastic words if well-enough ventilated.  I'll defer to others on fertilizer; I do my own thing with a mix of time-release and homemade fertilizers but don't consider myself an expert on mango fertilization.  I currently have just one potted mango, a 7 gallon Carrie; I water it once every six days, thoroughly.  Smaller pots = more frequent watering, larger = less frequent.  I don't prune much.  A little mist on the leaves won't hurt against spider mites but I haven't found that indoor/greenhouse pests tend to pester mangos as much as other plants.  I don't even mist it anymore since I moved to Iceland (I had more spider mite problems in Iowa).  I've never seen aphids or whitefly or scale or anything like that on an indoor mango.  Lastly, as for anything else: light, light, light.  Light is food to plants; don't starve them.  The sun yields 1000W per square meter when shining without clouds and straight overhead, and virtually all of that hits *something*.  Flourescent, MH, and HPS lights have light stray away and lose 70-80% of their energy as heat (the sun does waste about a third of its energy outside the visible spectrum, mind you, but nothing like what light fixtures lose).  Consider how many square meters of area a mango tree is.  Even though the average insolation of the sun, because of clouds, angles, night, etc is more like 200W/m^2 (give or take, depending on your location), you can see that the outdoors gives plants a *ton* of free energy.  Either give your plants sun, compensate sufficiently for their lack of it, or both!    Oh, and note that greenhouse glazing will lose you ~20% of your solar energy, so there's some loss even if you let 100% of the sun in..  If you want to save a bit on the power bill, use LEDs, although the fixtures are expensive.  Some plants hate LED light because of the narrow spectrum causing hormonal issues, but mangos don't appear to be among them.  It not only has a higher quantum efficiency (note: you want to compare quantum efficiency, not lumens/watt), but is also targeted at more ideal frequencies for photosynthesis.  But again, the fixtures are pricey.

Background: I've been growing mangos indoors for three or four years.  The first tree... let's just call it a learning experience about the dangers of mango root rot    My latest tree, however, has been going through growth flushes and is quite healthy.  No fruit yet, but hopefully not too much longer. 

He's likely panting due to the extreme heat here. Even the birds will do that. South Florida is basically just one big giant sauna.

Quote from: fruitlovers on June 12, 2012, 06:53:44 PM

Looks like that 'coon is hyperventilating.

I get overheated just thinking about south Florida weather 

While Iceland is a windy place, my apartment is not    Thanks for the info!

Hmm, been thinking about this - what do you think about:

 * 7 gal plastic pot, full of tons of drainage/air holes (already have such a pot)
 * Heavy sand at the bottom, mix of light gravel, soil, perlite, and vermiculite above it
 * Plant planted off-center
 * At the center of the pot running vertical is a piece of 3" PVC with a 2x2 inside of it, the 2x2 surrounded by sand, PVC capped on the bottom.  PVC extends a couple inches above the soil; it's only there to keep the post dry..  2x2 extends 3 1/2 feet above the soil; combined with the 1 1/2 foot height of the pot, that's five feet of dangle room for the fruiting arms.
 * 2x2 post is guyed at the top to the rim of the pot to help keep it vertical.
 * Plant tied loosely at regular intervals to the post.
 * No additional supports for the plant at the top of the post - it just terminates (are side supports at the top really needed?)
 * No protection for the 2x2 from the rootlets (just hoping that they don't do too much damage... they're not to bad, are they?)

Think that sounds reasonable?

Yeah, the rotting of the posts was one reason I was hoping to avoid wood.  But if the plant is really getting up to 200lbs, even large diameter PVC pipe might not be stable.  Steel would rust, aluminum probably wouldn't be strong enough unless it was pretty thick-walled... hmm, something to think about.  Perhaps I should just wander the isles of Byko or Bauhaus and see if I come up with some ideas. 

Lovely fruit there, by the way.

Yeah, didn't even think of that.  How much do you pay out in CO?  We're at something like 6 cents per kilowatt hour here in Kópavogur (I'd have to do the conversion again)

Pitaya are shallow rooted, and really do not need that much soil, but they do require moisture, unlike other cactus, they like to get watered often, and like lots of fertilizer.

I noticed that - I got a lot more growth when I stopped treating them like cacti and started watering them like normal plants.  Had the same surprise with pineapple, which I knew to be of a drought-adapted plant family.  Seems there's a big difference in the plant world between tolerating drought and requiring drought 

Also fungus is their biggest enemy, if part of the plant get injured, its best to just remove it,  well drained soil and watering often is best to prevent rot at the base.

Hmm... thanks for telling me that, because my largest plant does have an injury on one of its arms, a couple-months-old cut halfway through - yet it seems to be ignoring it and growing just the same.  Should I remove the part past the injury, remove the whole arm, or just let it be but keep an eye out for fungus?

I'll make sure that when I transplant up I go with mainly perlite, vermiculite, sand and gravel (the latter two being volcanic, so a bit porous).

Quote from: KarenRei on June 12, 2012, 10:04:01 AM

"...I have no clue how heavy the plants themselves get.  Anyone have any idea?"

A mature plant can weigh 200 lbs.

Um, wow.  Okay, scratch the idea I was toying with of a PVC support structure to prevent the sort of rot and rootlet damage you can get with wood...  guess it'll be the standard Big Wooden Post(TM) approach.

Question: it was mentioned that dragonfruit gets really heavy.  I want to get my largest one in a more permanent location within a couple weeks if possible, and ideal for me would be to hang him - but I don't know whether he'll ultimately grow too heavy for ceiling hooks.  I can calculate how heavy my soil and pot will be and minimize that (for example, a perlite-heavy mix), but I have no clue how heavy the plants themselves get.  Anyone have any idea?  All I find is recommendations to use a 10-15 gallon pot.

I have the same issue with most plants I move in and out of my house every year; they lose all of their "indoor" leaves and produce new outside-adapted leaves.

Are you not hardening your plants?  It's not a requirement that that has to happen...

To be fair, I don't think there's a person on the planet who could manage to consume 40 grams of resiniferatoxin     And yeah, I think any plants containing TrpV1 agents as powerful as resiniferatoxin are properly named "toxic"    Again, like capsaicin, it won't injure you directly, but you tick off your body so much that it attacks itself!

Cacao is such a lovely tree.  The new leaves that come in are so paper-thin they're translucent, just so delicate, but then grow super rapidly to large size before firming up.  It's kind of like watching a banana plant grow, where you can easily see the difference in growth from day to day.  I just potted mine up from a 3 gallon to a 7 gallon; hope it likes the extra space.