growth issue

[solid7]

Even though Solid7 is much further away, he may have better insights as to how to manage sandy soil.

 
Unfortunately, I cannot, as I don't actually have sandy soil.  I only have sand. 
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I live a couple blocks from the beach.  There is nothing that resembles soil for miles from here.  No tilth, no mineral diversity.  If it's not a native or sand loving plant, I have nothing to do with it, in ground.
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I also don't know if the drainage is an issue.  To be honest, the last week here, the heat came on like a hammer, and it's just been brutal.  All of my plants droop in the day, and most growth has come to a halt.  Any of my plants that weren't growing at absolute optimum, really came off the worst.