Mysql sort by date not working as expected

I am pulling records out of my mysql database using php and want to order them by a database field called expdate. The dates for the reminders are stored in the table in this format 17-04-12 as varchar. I am using the following code to pull all the records out and order them by the expdate column. ``` <table border="0" style="text-align:left;"> <tr style="text-align:left;"> <th style="text-align:left;" width="200px" scope="col">Name</th> <th style="text-align:left;" width="200px" scope="col">Email</th> <th style="text-align:left;" width="200px" scope="col">Telephone</th> <th style="text-align:left;" width="200px" scope="col">Current Cover Expires</th> </tr> <?php $today = date("d-m-y"); $result = mysql_query("SELECT * FROM ymeg_chronoforms_data_NewsletterSubscribe ORDER BY expdate")or die(mysql_error()); echo '<tr style="text-align:left;">'; while($row = mysql_fetch_array($result)) { echo '<td style="text-align:left;">'; echo $row['name']; echo '</td>'; echo '<td style="text-align:left;">'; echo $row['email']; echo '</td>'; echo '<td style="text-align:left;">'; echo $row['tel']; echo '</td>'; echo '<td style="text-align:left;">'; echo $row['expdate']; echo '</td>'; echo "</tr>"; } ?> </table> ``` The problem is, the columns are being sorted quite randomly, it outputs the records and sorts them by this date order : ``` 08-07-12 17-05-12 17-05-13 ```