Green Panda withering in intense heat

[Alan_L]

I said I wouldn't put a bag over the plant while it was in the sun. Although it would certainly preserve moisture loss -- which was your thinking, right? -- it would also get really hot under the bag. Maybe the high humidity would balance out the higher temps, but I wouldn't risk it. Maybe a plastic bag with some ventilation holes would be a good compromise. Or maybe this plant doesn't get enough sun to be worried about the greenhouse effect.

I just didn't want that Rufa to get cooked alive. I should have added more detail to my original statement.

[jd.]

why is that alan
increasing the humidity is NOT gonna adversely effect that plant...

Well duh... it's not the humidity Alan was so concerned about.

So it seems BooManChu is itchin' for a fight!

haha, only way to solve this now, is you two fight with bamboo sticks and whoever loses has to give me free bamboo to kill. This is a good punishment.

I second the motion!
Fight! Fight! Fight!

[foxd]

Hmmm...I was reading somewhere that a lot of the water a plant uses goes toward cooling the leaves via transpiration. It would seem to me that covering the plant with a plastic bag would prevent this and make the plant more susceptible to heat damage.

[jd.]

Hmmm...I was reading somewhere that a lot of the water a plant uses goes toward cooling the leaves via transpiration. It would seem to me that covering the plant with a plastic bag would prevent this and make the plant more susceptible to heat damage.

Conveniently for cooling, the most damaging temperatures tend to enhance evaporation or transpiration.

As moisture capacity of air increases at an increasing rate with higher temperatures, heating a fixed air mass reduces relative humidity which in turn enables more water loss due to evaporation and transpiration. Here's a graph where you can get an idea on how thirsty the air becomes with temperature: http://en.wikipedia.org/wiki/File:Relative_Humidity.png

If the roots lack the capacity to move enough water to compensate for increasing transpiration losses, leaves can become dehydrated and damaged.

If the intent of the plastic bag is to reduce transpiration losses by increasing relative humidity, it must be deployed in a way that does not raise the temperature of the enclosed air. In other words, avoid using the plastic bag where it can act as a solar heat collector.

[ocimum_nate]

I'm with Alan on this one. I have taken cuttings of plants and put them in a white trash bag and have found them quite capable of building up excessive heat as well because light can still enter and build up heat. Any how just my two bits

[BooManChu]

OMG.
You all are amusing.

First of all... When I say put the garbage bag over the plant for a little while, I mean say, couple hours during the day when the suns beatin' down on it the hardest. - Just to relive the sunburn stress issue. NOT to keep the bag on for six months.

Take it where you want it...

Second, the plants gonna transpire just fine. There'd still be air movement, I'm not talkin' about sealing the bag...

I would be willing to put up money that it'd be fine.
We put bags around lotsa things down here.
Alot of nurserys collect pollen from plants using such a method of baggin' the entire plant in clear plastic to collect it... NOT for six months straight; of course.

You all should be a little open minded about things.
There's always room for improvement and change.

GrowOn&GrowStrong my friends...

~BMC.

[jd.]

OMG.
[...] it'd be fine.

Oh oh!
That one's just begging for a crude analogy, but I shall restrain myself.

You all should be a little open minded about things.
There's always room for improvement and change.

A prior informal experiment on a stressed potted plant demonstrates the effect. First a bamboo plant (Phyllostachys aureosulcata) spends a week where there's shade most of each day, and shows water stress (leaf curl) at the end of each day which it always recovers from by the following morning. Then for one afternoon, on a day not any warmer than the one before it, the same plant is placed in the sun shielded inside a white plastic bag with the only opening at the base of the pot. Again, the plant shows water stress at the day's end, but this time the stress is too much for all of the leaves to recover.

After being returned to the shade, the remaining leaves that did not wither away recovered.

But you wouldn't be prudent to allow theory to sway you after just one result. For more reliable, informative, and complete results, someone must run more extended trials with multiple stressed plants under varying conditions.
For that someone, I nominate Iowaboo.

Send Lance free bamboo to kill!

Meanwhile, the white translucent plastic as used in tree shelters is deployed for months at a time with a protective effect. The plastic shields the direct rays of sunlight while the open top does not permit an excessive accumulation of heat as hot air rises. The presence of a rigid top vent can make the difference between helping and hindering a plant's health.

[BooManChu]

you guys rock the bamboo world. i swear.

~BMC.

[utahraptor]

This heat wave is getting pretty bad. I would say half of the Rufa is burnt away at this point. There are no sub 100 degree days on the horizon.

[Iowaboo]

you guys rock the bamboo world. i swear.

~BMC.

Thanks, my mom says I'm special, too. Let me know if you want other references, also.

[Tarzanus]

Keeping any plant in any kind of sealed bag during hot summer day would most likely be fatal. If it's not sealed, moisture would get out and you would gain nothing.

I would recommend this practical solution. I use it regularly