The link below will take you to a post that discussed yellow rhododendron and yellow azalea recommendations. Note that some of the recommendations were not good for the poster because he/she was in Z6 but they should work for you in Z8.

Here is a link that might be useful: Post to

Good luck. I mean this part sarcastically, but sincerely.

Most yellow rhododendrons are quite susceptible to root rot and root rot flourishes in areas with hot, wet conditions, especially warm nights and especially with less than perfect drainage.

Work is being done to find good rhododendrons for the south, but results to date don't include yellows as far as I know.

On the other hand, many good yellow azaleas exist. Check with local extension agents for a yellow. If you can't find any, check out azaleas.

rhodyman, ggardens is in PNW, cool summers and wet mild winters - not much in the way of heat to contend with other than some better temps in Aug and Sept when its typically dry - but I think you know that already :).

Ggardens, if I were you in your location, I'd make a stop at Valley Nursery or Bainbridge Gardens and see what they have to offer in the way of yellows. You'll find experienced staff to advise and guide you towards disease and insect resistance at either, and either would be a fun place to spend an afternoon - I try to make a day trip doing that later in Spring each year.