If you are concerned about radiant heating from the sun, you only need to protect the side of the pots that receive low angle insolation. And if you have a cluster of pots the outer ones will shade the interior ones. In my overwintering sun-porches, I solve this with a strip of opaque plastic affixed to the south walls from the shelf up to the height of the pots. In the summertime I have no problem with morning sun because of trees or mid-day sun because of elevation, but I need to protect the western to west by northwestern exposures toward sunset. An empty row of pots works well or any opaque plastic or barrier will do. Some nursery suppliers even sell a "pot within a pot" system for trees. A moist, loose soil with lots of air porosity is the worst actor because it will act as a heat pipe, conducting the hot water vapor toward the interior of the pots, killing far more roots in the process. Tim in Pennsylvania On Mon, Apr 27, 2020 at 8:05 PM Jim Barton via pbs < pbs@lists.pacificbulbsociety.net> wrote: > Does anyone grow California native bulbs in 1 gallon black pot in the > Central Valley of California? The growing medium in my pots is becoming > much hotter than the native soil where many of my bulbs are planted. Last > weekend I made a shade structure of ½" gray PVC pipe and shade cloth, in an > attempt to keep the pots cooler. The heat seem to be drying out the stems > before they finisher blooming. Any other ideas? > Jim Barton > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > http://lists.pacificbulbsociety.net/cgi-bin/… > _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/…