Or you can make link to the Daylily database, and add it to your signature block.
Got to "your Profile" from the Blue MenuBar or the top line of the HomePage.
Then edit "Signature appearing below your posts:"
Then, you'll be able to go to TreeMail, find a mail from yourself, and click on your link. But that's probably more work than using a browser bookmark. It is available from any PC, if you browse from more than one pC..
Let's see if this works ...
Daylily Database
(Remove the spaces after this bracket: "[" and before this bracket: "]"
[ url=http://garden.org/plants/group/daylilies/ ] Daylily Database [ /url ]