Once you become a YouGarden Member, you first need to register for a web account. The link is here  Make sure you use the same email address you used when purchasing your membership. Now, log in prior to ordering and you will find that your discount is automatically applied and you will have access to your membership vouchers. 

If you have done that and you haven't got the discount you expected, it may be that you have ordered from our Outdoor Living range which is 7.5% discount.  15% only applies to plants and accessories.  

Its also possible that your automatic membership has not renewed  if your card has reached its expiry date.  If this has happened, simply purchase it again with your new card details, and you will get your 15% discount straight away. 

If this does not fully answer your query and you are not able to find a relevant article, please raise a Support ticket using this link