Emersed plants surviving under extreme temperature conditions

[helpmegrowinganubias]

I recently moved, and before moving, I sent a few plants in emerged form, which ended up in direct sunlight for many hours a day. In my city, the temperature currently reaches about 41 degrees Celsius at its peak, which turns a closed plastic box with high humidity inside into a steamer. Most of the plants, for obvious reasons, have melted, but surprisingly a few have survived, and I wanted to share the results in case anyone finds them interesting.



I measured the temperature at 7:30 PM. At that time, the sun doesn't shine on the boxes, so the temperature is low. However, the purpose is for you to see the difference between the inside and outside of the boxes.



Now i´ll show you photos of the surviving plants:



All the Cryptocorynes died, except for the wendtii "green gecko".




The Hygrophilas seem to be especially heat-resistant (excluding the lancea chai, which I never had luck growing emersed, so I can't determine if heat was what killed it).




I think this is a Ceratopteris (I have to identify most of the plants I receive myself, so I hope it's correctly identified).



All Alternantheras survived.



The Lobelias are not at their best, but they are surviving.



Of the Limnophilas, only the hippuridoides mini survived, and it is growing quite well. The good condition of the Nesaea pedicellata was a great surprise for me, at least.



All the Rotalas survived except for the macranda mini type 4 (with which I also haven’t had much success growing emersed, so it's not possible to conclude that the heat killed it) and the rotundifolia varieties. I found it curious that I only found new shoots in the H'ra (attached photo).



Of the Bacopas, only the salzmannii died, but it seems that the caroliniana does not adapt as well as the monnieri.

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With this, I’ll end the post. I’d like to hear your opinions, as well as your experiences growing plants at high temperatures. If anyone has any questions or wants additional information, I’ll try to respond as promptly as possible.

Thank you for reading.

 

[Art]

Hey thank @helpmegrowinganubias for the detailed post and sorry to hear of your plant loss. Always an issue when moving.

For the non-Celsius crowd, that is 105.8F. That is quite hot but having lived in Texas not too long ago, I'm starting to get used to that.

I think of a few things as a result of your post. First is that temperature is not something many of us think about. This was mentioned in another post recently. However, it does play a role even at much lower temperatures than this. Certainly I think about it more in South Florida but may we all should start to given how the world temps seem to be heating up?

I would expect that all plants have a threshold and the more delicate ones would logically have a lower threshold to heat. This is seen by the delicate ones you lost @helpmegrowinganubias. However, the fact that not all of them died is testament to the hardiness of most, especially in emersed form. Some come from very tropical locals where day-time temperatures do reach quite high. Perhaps @Krandall can give us a sense from her travels and testing in the Amazon?

You didn't mention how long the plants were under these conditions. I'm sure that has a big impact as a temporary increase in heat will be better for them than extended conditions.

I grew plants emersed in the South Florida heat many years ago. I would say the ambient temperature in the makeshift greenhouse would be 85 - 90F during the days. I did use growing shade cloth on some of the more delicate or younger plants but had many in full sun. However, as CO2 was not limited and nutrition was abundant given the hydroponics, I never had a problem growing any plant I tried.

Anyone have any other experiences? @helpmegrowinganubias are you going to continue to grow these outside?

 

[Krandall]

Some come from very tropical locals where day-time temperatures do reach quite high. Perhaps @Krandall can give us a sense from her travels and testing in the Amazon?

While temps can certainly get hot in the Amazon, there are also many fewer aquatic plants, and these temps are, perhaps, less common. Especially for prolonged periods. Where we DO see these temps are SE Asia and NT Australia, where many beautiful aquarium plants hail from. I think that two factors are at play. First, in these boxes, there is little to no air flow, which is not the case in nature.

Second, if the air temperature is 105°F, my guess is that the temp in the boxes is actually significantly higher. (Think temp inside a closed car, even parked in the shade). When collecting, we ALWAYS took our boxes out, put them UNDER the car, for shade, and cracked the lids for air movement. Oh, and if there was a choice between collecting emersed and submersed specimens, we always chose emersed ones, because they tolerate abuse so much better.

 

[helpmegrowinganubias]

Hey thank @helpmegrowinganubias for the detailed post and sorry to hear of your plant loss. Always an issue when moving.

For the non-Celsius crowd, that is 105.8F. That is quite hot but having lived in Texas not too long ago, I'm starting to get used to that.

I think of a few things as a result of your post. First is that temperature is not something many of us think about. This was mentioned in another post recently. However, it does play a role even at much lower temperatures than this. Certainly I think about it more in South Florida but may we all should start to given how the world temps seem to be heating up?

I would expect that all plants have a threshold and the more delicate ones would logically have a lower threshold to heat. This is seen by the delicate ones you lost @helpmegrowinganubias. However, the fact that not all of them died is testament to the hardiness of most, especially in emersed form. Some come from very tropical locals where day-time temperatures do reach quite high. Perhaps @Krandall can give us a sense from her travels and testing in the Amazon?

You didn't mention how long the plants were under these conditions. I'm sure that has a big impact as a temporary increase in heat will be better for them than extended conditions.

I grew plants emersed in the South Florida heat many years ago. I would say the ambient temperature in the makeshift greenhouse would be 85 - 90F during the days. I did use growing shade cloth on some of the more delicate or younger plants but had many in full sun. However, as CO2 was not limited and nutrition was abundant given the hydroponics, I never had a problem growing any plant I tried.

Anyone have any other experiences? @helpmegrowinganubias are you going to continue to grow these outside?

Hi, they have been there for almost one month. I think I will continue with the experiment to see which ones i can keep there for more time, and also a cold resistance test.

 

[RickyV]

I’d like to hear your opinions, as well as your experiences growing plants at high temperatures.

So far I only have experience growing hydrocotyle verticillata in high temps. I have a small creek I built I sometimes throw clippings in. The hydrocotyle is the only one that's been thriving outside in the Texas heat. It's been over 100 F almost every day. Edit: So I am seeing that this is native to the southern US so it makes sense it is doing so well lol.

 

[Krandall]

This plant also grows in streams in Mexico, where temps are very warm. There are actually LOTS of beautiful plants that were more popular in past times as aquarium plants that grow in such places. I have lovely photos from a collecting trip there a number of years ago, but I’m not home atm, and don’t have access to them right now.