18 gal earthtainer heat problems: 99 deg even with sunshade

Vespertino · July 11, 2013

My balcony hovers in the low to mid 100's daily thanks to the radiant heat island effect. As a result the temp inside my earthtainers is 99 degrees this morning, even with a sun shade. I stuck a therma-pen into the soil to see what the reading was.

My earthtainers are smaller than the standard 31 gallon, I made two 18 gallon ones since my balcony is really small. I'm guessing in an environment like mine where the temps stay high over 100 for most of the day, the 18 gallon ones heat up much faster since they're smaller, and perhaps more prone to swings in temperature than a 31 gallon would be.

My sungolds are just fine, but my Brandywines have been noticeably suffering : major BER (cal mag didn't fix it), stunted growth at the top, fruits that were set grow very small, and this week I noticed little bumps forming on the lower stem- all signs of root stress as far as a newb like myself tell. The BER has subsided since I added the sunshade on the earthainer, but no improvement otherwise.

While I'm inclined to blame the heat warming up my 18 gal 'tainers, I'm a novice so I'm wondering if it might be other factors?

1) Maybe the brandywines need more root space- while a 31 gallon 'tainer can hold two, perhaps and 18 gal 'tainer is better suited for one plant? I have 2 brandywines in the 18 gal 'tainer, maybe the roots are crowded?

2) I'm using Lady Bug Brand square foot mix in the 'tainers. They use coco coir instead of peat. Too much moisture retention? I'm not sure about this, since it's an issue with the brandywines in one earthtainer, while my sungolds in the other seem perfectly fine. Sungolds are known for being more heat tolerant, so if it were a moisture problem with the mix wouldn't I be having problems with the plants in both earthtainers?

3) Maybe it's just the Brandywines themselves? Maybe the size of the earthainer doesn't make a difference? Perhaps they just don't grow well in earthtainers where the summers are as hot as mine (North Texas). Perhaps I should have gone with a variety more suited for the weather, like my sungolds are.

Anyway I think my branywines are kaput. I have BBB and SCP plants growing in pots to replace the BW's in August for the fall season.

July 11, 2013	#1
Vespertino Tomatovillian™ Join Date: Apr 2013 Location: Southlake, TX Posts: 743	18 gal earthtainer heat problems: 99 deg even with sunshade My balcony hovers in the low to mid 100's daily thanks to the radiant heat island effect. As a result the temp inside my earthtainers is 99 degrees this morning, even with a sun shade. I stuck a therma-pen into the soil to see what the reading was. My earthtainers are smaller than the standard 31 gallon, I made two 18 gallon ones since my balcony is really small. I'm guessing in an environment like mine where the temps stay high over 100 for most of the day, the 18 gallon ones heat up much faster since they're smaller, and perhaps more prone to swings in temperature than a 31 gallon would be. My sungolds are just fine, but my Brandywines have been noticeably suffering : major BER (cal mag didn't fix it), stunted growth at the top, fruits that were set grow very small, and this week I noticed little bumps forming on the lower stem- all signs of root stress as far as a newb like myself tell. The BER has subsided since I added the sunshade on the earthainer, but no improvement otherwise. While I'm inclined to blame the heat warming up my 18 gal 'tainers, I'm a novice so I'm wondering if it might be other factors? 1) Maybe the brandywines need more root space- while a 31 gallon 'tainer can hold two, perhaps and 18 gal 'tainer is better suited for one plant? I have 2 brandywines in the 18 gal 'tainer, maybe the roots are crowded? 2) I'm using Lady Bug Brand square foot mix in the 'tainers. They use coco coir instead of peat. Too much moisture retention? I'm not sure about this, since it's an issue with the brandywines in one earthtainer, while my sungolds in the other seem perfectly fine. Sungolds are known for being more heat tolerant, so if it were a moisture problem with the mix wouldn't I be having problems with the plants in both earthtainers? 3) Maybe it's just the Brandywines themselves? Maybe the size of the earthainer doesn't make a difference? Perhaps they just don't grow well in earthtainers where the summers are as hot as mine (North Texas). Perhaps I should have gone with a variety more suited for the weather, like my sungolds are. Anyway I think my branywines are kaput. I have BBB and SCP plants growing in pots to replace the BW's in August for the fall season.