I much prefer to upload my FULL sized photos to Photobucket.com, (it's Free!)
then just copy the "HTML Tag" Just Below each photo on your photobucket
page. Next paste that "Tag" into the message (right here) in the body
of the post on GardenWeb.
You can also do multiple Pic's in the same post. Simple and
no resizing and you can see your pictures when you preview the
post before you click the "submit message" button.

HTH
Chris

Don't paste it on the link box below the post, just put it right in
the message above or below your post.