You can’t delete your account, unfortunately.
Try to ask for deletion on the forum, or ask for account removal using this form: http://letters.gardenweb.com/letters/nph-ind.cgi
If this doesn’t help, you can always anonymise your data. Read the tip below.
URLS:
http://gardenweb.com
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.