<?php
$username = "root";
$password = "";
$hostname = "localhost";

//connection to the database
$dbhandle = mysql_connect($hostname, $username, $password)
  or die("Unable to connect to MySQL");
echo "Connected to MySQL<br>";

$selected = mysql_select_db("accordion",$dbhandle)
  or die("Could not select nueva");

  $result = mysql_query("SELECT id,planta FROM nueva where id=1");

  while ($row = mysql_fetch_array($result)) {
   echo "ID: ".$row{'id'}."  "."Planta: ".$row{'planta'}."<br>";
   $planta=$row{'planta'};
   $ID=$row{"id"};
}

?>

var accordion=  $("#accordions").val();
    var PHP_VARS = <?php echo $planta; ?>;
    for (var i=0; i<PHP_VARS; i++) {
        $(".accordion").append("<li class=tabs><div class=paragraph><h1>Accordion</h1><p>Esto es una Pruba.</p></div></li>")
}

$(".accordion").click(function() {
   $(".tabs").css("width","300px");
});

<div class="container">
    <ul class="accordion">



    </ul>
  </div>