Soil/Containers getting too hot?

[LuZiKui]

I've got my plants sitting outside and in the afternoons when I check the soil it seems very hot. They're mostly in black nursery containers and the sun shines directly on them for 3-4 hours in the hottest part of the afternoons. Is this something that I need to be concerned about? I was planning on sticking a thermometer in this afternoon to see what the temp gets up to but it feels pretty dang hot. If it is a big issue is there something I should do to try and mitigate the heat?

 

[Emanon]

I don't know if it will help or not, but some time ago I asked in the forum how to reduce substrate temperatures when using plastic pots (not whether you should be concerned with doing so in the first). Some good answers were posted. I ended up just painting most all my pots white with a roof coating I had laying around. A few years later and they're still white, with no chipping or peeling, and easy to wipe down. I don't know if it's helped at all though. My substrate definitely takes a lot longer to dry out now and I'm watering a lot less (Aoki mix mostly).

Here's the direct link to the thread: https://www.bonsainut.com/threads/r...hen-using-a-black-plastic-training-pot.43373/

 

[LuZiKui]

I don't know if it will help or not, but some time ago I asked in the forum how to reduce substrate temperatures when using plastic pots (not whether you should be concerned with doing so in the first). Some good answers were posted. I ended up just painting most all my pots white with a roof coating I had laying around. A few years later and they're still white, with no chipping or peeling, and easy to wipe down. I don't know if it's helped at all though. My substrate definitely takes a lot longer to dry out now and I'm watering a lot less (Aoki mix mostly).

Here's the direct link to the thread: https://www.bonsainut.com/threads/r...hen-using-a-black-plastic-training-pot.43373/

right on, thank you for the info I'll check it out!

 

[Firstflush]

Reflective/mirror packing tape

 

[Deep Sea Diver]

The biggest issue might be the use of plastic pots allowing the sun to transfer energy to the inside of the media/roots, dry and eventually heat up and burn the roots nearby. Covering these pots with aluminum foil, shiny side out, out to shield the pots from heating up.

Yet its well worth spending 15.00 to check. Here's the type of instant thermometer I use for media temperature trials in the winter.
Digital Instant Read Meat Thermometer for Cooking, Ultra Fast & Precis Waterproof Kitchen Food Thermometer with LCD Backlight, Foldable Probe, for Gri

Cheers
DSD sends

 

[nuttiest]

Yes! I noticed today a lot of plants have leaf curl (I hope it's not viral) the difference this week is we have no cloud cover for two days straight. Maybe I should spray the sides of containers too right at peak heat, like 4pm.

 

[Deep Sea Diver]

Best idea I’ve heard of is put pot in another pot same size or a bit larger. An airspace is an excellent insulator Then wrap pots in aluminum foil. Shiny side out. Likely more effective then painting IMHO.

Ok this question provoked my inquisitive side!

To get a handle on the magnitude of this issue I took two trees in plastic pots and put these in direct sun light. Then put a thermometer inside at pot edge. Then 1” in from the edge.

110.3F. and. 90.4F


Then another with branches providing shade and a bit more wet media.

91.4F 86.9F



After watering both edge temperatures were about 77F and then began to rise.

Being off an inquisitive nature once again I then measured inside the edge and 1” in from the edge in a tree planted in a ceramic pot.

82.2. And. 76.4F

Outside temperature in the shade 80.2F

And that’s all folks!

Cheers
DSD sends