So Bob, you say that "they work good". However, I doubt that you have done a scientific experiment with an experimental (black containers) group and a control (not black) group to see which is most conducive to tree health. So, how do you know that "they work good" regarding black containers?

By the way, black containers are not beneficial when ambient temps are 85 F, because container temps can be 100F or higher and studies have shown that citrus trees suffer at these temperatures.

I suggest you read this: https://www.researchgate.net/publication/265321448_Summary_of_Temperature_Stress_Issues_in_Nursery_Containers_and_Current_Methods_of_Protection

Vlad, all my containers are black except one square one, like that one, it’s white and way over 20 years old. Summers here are hot. From July 15 to end of August 30 is usely the duration of hot temps. My tree’s are kept short but somewhat wide to keep the sun from hitting the containers. I have shown enough pictures how to arrange my tree’s. Ultimately my tree’s are very healthy and not showing stress. This past week have started to clean grasses and wild flowers away from containers, why because the remaining weeks shows temps in the low nineties and high eighties, that’s pretty good for my tree’s.

Bob my trees are mostly in black containers too so far so good but my yard is on the shadier side. ill have to buy garbage bins or something next year cant find pots big enough.

Vlad interesting article!

My containers are mostly black except for the largest ones. Since my citrus get shaded in later afternoon, it hasn't been a problem. Plus, it rarely gets much above 95ºF here.

Vlad, no damage here.

Jan, the ultimate size container for me is 15 gl, these are actually 13.6 gals. I get mine at my favorite hydroponic store here. They are squat containers and cost me $8.00. They are heavy duty kinds will last a long time. They have a large lip for easy dragging or lifting and have large square Drain holes, good for aeration. I believe the name is GrowPro.

I have experimented this exact issue on a sunny summer day.. Placed a citrus black container in the sun with a thermometer 2 inches from the inside container wall. Within 5 minutes the temperature were 99 to 101 F. After 15 minutes the temp reached 121+ F. Citrus roots are killed at these temperatures.

vlad or bob any idea when temps are 100* the difference in temo with the same containers one being black and the other color white or gray. Could the temps difference be as high as 20*

For me, it doesn’t matter. 95* and up you got take precautions. White color is only good for so long, than they get Heated just the same.

Vlad, probably has a better idea, he,ll chime in and others, white containers are not cheap for the larger sizes I am using.

In my case, black containers are better for the 10 months out of the year than white ones.

When they get holdup for the winter, temps there are a constant 65*.

What about wrapping them with a burlap type material would that help ?

That only black containers I use for my smaller citrus are rootmaker 7 gallon thick molded pots that are 15 inches in diameter and I use them as well with my Japanese Maples.

Bob What is Low Buirate ( urea). Brand?

Steve

Someone here in some post suggested to spray paint a black container white and it worked just fine. I have a assortment of white, terra cotta color plastic containers. Spray paint is the way to go since I wash out and save many from nurseries. whoever suggested that great idea.

Steve, I learn this from Millet, Tropical citrus forum. He wrote about it many times. It works.

I can explain it if you want or check with him. He likes to explain to you in detail..

I am trying out with micro,s only around December for the first application. I think it has the same effect this coming winter, way before bloom. It’s a 3part ap.

This is what you need.

Steve: https://www.amazon.com/gp/product/B007OAYGEA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

If you want to experiment a bit try this, take a piece of plywood 12” high x 16” wide, 2 long nails or screws to hold the board in place. Push the nails in dirt to hold the board at a angle, about 45 degree. Why 45 because the air underneath the board will be cooler.

No paint, no burlap, just try! The board should face the sun between 12 and 5 afternoon.

Citrus can tolerate black containers in my area of Southern California and we often get triple digit temperatures in summer. I have a Moro that is in a 15 gal black nursery container set on concrete with full sun exposure. It did not get phased one bit, but of course I had to water almost everyday during summer. One thing I love about citrus is they can take full sun where many plants rated as full sun need to be protected here.