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View Full Version : can it be too hot for containers, even really big ones?


hanabananaman
07-07-2012, 05:21 PM
I am in zone 9B and know the benefit of planting in the ground but am wondering if anyone has had success with containers in such a hot area. I have great afternoon shade and use foggers to keep the yard much cooler than the 110 plus we get. T+R has some nice wide 65 and 95 gallon containers that I hope will be enough.
Stay cool folks, hope you and yours are doing OK in this insane heat.
Larry

Update on 9/14/12
I am going to try a DC in a 25gal and see what happens. I did pick up 45,65,and 95gal containers. Decided the 2 big ones will be for mango and loquat trees. I might get some 35's for the other bananas. My question is there a point of diminishing return with size. I don't mind doing 45's if it helps. This next question will be put on the appropriate forum but in case anyone can help, is there a benefit to stepping up container sizes over several years with the mango and loquat or is a giant container OK to start.
Thanks for the advice
Larry

TommyMacLuckie
07-07-2012, 06:15 PM
A friend of mine in New Orleans has three containers with plants in them that get full sun almost all day. It gets up to 120, 130 in the sun here. They wilt everyday. They need to be watered everyday. If they're watered everyday in the morning and evening they should be OK. At some point there is a 'too hot' but I don't know what that is.

Abnshrek
07-07-2012, 07:43 PM
I have a R. Iholena in a black 15 gal container that was in full sun and stopped growing. and I moved to 60% sun and w/ a mister and it has grown well since then. The sun can't hit its pot since its surrounded by other light colored pots. I have D Red in 80% sun in light colored pot and its doing great. :^)

palmtree
07-07-2012, 08:08 PM
I think they will do okay in containers. Some bananas will do better than others. My bananas in the hottest parts of the yard usually wilt during the day and they are in the ground so I would imagine they would wilt even more in pots.
Try and shade your bananas from direct afternoon sun. The good thing about pots is that you can easily move plants if they dont do well in a certain spot! If your banana never dries out, it shouldnt have much of a problem. Not sure how hot banana plants can handle, but my guess is that once you get to 110F, your dealing with some dangerous heat for potted banana plants in full sun even with water.

Bob3
07-08-2012, 06:15 PM
We put a slab of that insulated silver "bubble wrap" (the stuff they make "freezer bags" out of) around the big dark colored pots; it keeps the poor things quite a bit cooler.
The mister runs afternoons for the mat that's in the "warm spot" of the yard.
(great spot to stash a lawn chair) ;)

venturabananas
07-16-2012, 12:01 AM
I've read that anything above about 90 degrees will slow or stop banana growth. I'm sure the misters must help, but there's only so much you can do, short of bringing them indoors into the AC! :ha:

sandy0225
09-13-2012, 08:37 PM
if you have mist on them, they can take 110 easy in the greenhouse, but I put them under 30% shade and keep them well watered, when it's that hot in there. Which it was pretty much every day this summer. if you let them get too dry when it's that hot and then you get some breeze while they're still dry, the leaves shred just like when they get frosted, and then the wind blows....

LilRaverBoi
09-13-2012, 10:57 PM
I'm no expert on this since it isn't quite as hot/dry as it is there, but based on plenty of pot-growing, I'd recommend watering twice a day (as needed, obviously) in the mornings/evenings and consider painting the outsides of the pots white or silver to reflect light to keep soil temps down. (I kinda wonder what some aluminum foil could do for an alternative to painting....hmmmm)

Abnshrek
09-14-2012, 12:00 AM
Like Sandy said a Mister(s) ( I prefer in mass (like a 4 head mister)) works wonders.. My Red Iholena (finicky in a pot but grows great in the ground) is doing great w/ 2 pups now, and anything in a pot near the mister is doing great. The one on my Goldfinger stays on unless its raining or it actually cools off around here. :^)

Doglips
09-24-2012, 02:22 AM
OK, 3 kinds of heat transfer.
Radiant ( the sun's rays makes pot hot)
Conductive (hot pot makes soil hot, makes roots hot (touching))
Convective ( using misters to make cool air to replace hot around the pot)

If you are cooking the plant above ground, in or out of a pot is not relevant.

If the temperature outside is 100F then your roots are 100F (at least). Deal with it.

Misting (essentially convection)
Evaporative cooling's (misting) effectivness is realtive to ambient humdity in the air. Low humidity means good evaporation and thus cooling. If you live in sticky Florida, ain't gonna help much. If you live in Phoenix, big help.
Air misting can help pots, a little. Cooler air passes by the pot, the air wicks away a little heat from the pot. If you can lower the outside air temp then you will lower the pot temp. As far as cooling the roots go, you would be far better off by watering the outside of the pot, a greater potential for evaporation.

Conduction
One hot object touching another object to make it hot. Placing a pot on blacktop equals roasted roots. A pot on wet earth can help wick heat away.

Radiant ( The big one!)
This is what this thread is about. Convection and conduction strategies are about trying to win a losing game. Removing the radiant threat gives you a cool pot to begin with, as opposed to trying to cool the hot pot. In short, keep the sun off of the pot. Light does one of two things when it hits an object. It either reflects or absorbs (refracts). Lighter colors are more reflective. When light gets absorbed, thats radiant heat. So, a light colored pot is good. So is wrapping it in a light colored fabric or aluminum foil (aluminum foil is champ, just looks like crap), as is painting it (careful with this one). Placing an object between the sun and the pot is a big help (just the pot not the plant). Just don't have the blocker touch the pot (see conduction above).

Silver bubble wrap...
The silver blocks the radiant heat, big help. The fact that it is bubblewrap.... not so much. It does help a little by keeping the reflective material off of the pot reducing conduction. Bubble wrap's strength is in blocking convection (air flow), so it could actually have a negative effect on misters or any other cool air source. But it could help if blowing hot air is an issue. Aluminum foil is the monster blocker of radiant heat. Silver bubble wrap, ya, go for it. A '57 chevy blocks the sun pretty good too.

Combination of strategies is best, but radiant should be the priority to block.

Water the plant as it needs it, don't water to cool it. Obviously if the plant is thirsty, then give it a drink. Don't drown it to cool it.

Will a bigger pot help?
maybe.
It depends on temperature fluctuations. How much for how long. If the burst of heat is high for a short period then a bigger pot can help because of its thermal mass. It slows increase and decreases in temperature change, potentially lowering temps below the level that will damage the plant. If the temp is 70 overnight then 100 at sunrise and stays that way all the way to sunset, then the pot size ain't gonna help (unless you have an Earth sized pot). It will help for a bit at sunrise, but that is it. The amount of temperature fluctuation that can be mitigated is relative to pot size.

At what temps do you get roasted corm? mmmmm, dunno. Ask an expert. I'm sure cultivar has much to do with it.

hanabananaman
09-25-2012, 10:35 PM
Thanks for the info Doglips. I am currently using small pieces of plywood to shade the pots, it's a bit of a hassle to move them every few hours but it helps.
Larry

andy17
10-04-2012, 10:12 AM
Hey Larry,
I've been growing several banana varieties in the Deep South and I have found that container choice and placement are really important. I originally had them on a two story deck in 3/4 sun, and during our insanely hot summer, they really struggled to stay healthy and alive. I moved them down sometime in August to clean the deck and left them for a week or so on a concrete patio in filtered sun underneath the deck, about 1/2 a day of full sun max. I was expecting them to decline further, but they took off again. In fact, they looked so much better, that I've left them there since. Many of the signs of severe stress disappeared; apparently the roots and soil were literally baking in the sun and heat and it was killing the plants. The cool of the concrete and filtered sun did wonders for keeping the soil much cooler and more stable in temperature--that seems to be the biggest factor in keeping them happy in high temps. I've also been using smart pots which the bananas seem to really like, although pots dark in color seem to act as a solar oven in mid-summer. I hope this helps! Best wishes

hanabananaman
10-04-2012, 10:36 PM
Thanks for that info Andy, you just confirmed for me a similar situation this past summer. I thought I was doing good by a bonanza peach and an almond tree by wheeling it on my laid down dolly into the shade during the heat of the day, but being off the ground was letting it cook like you described. The peach survived but I think the almond is kindling now. :ha: Oh well, I know more are at the store, try try again.
Thanks,
Larry