Of plants and bridges and research

What plants will win a spot in my book? I have a landscaper (or IS he?) hero, advising my heroine on plants in her yard. Granted, this does not further the plot, except as an excuse for the two of them to meet, and meet again, and talk, and wander around the backyard together, and for her to notice his green eyes and other attractions. But I can't just stick any old plant in the ground!

My story takes place in Oregon--the Willamette Valley, specifically. I live in California--in the South Bay area--Silicon Valley. Plants grow better one place than another, so talking to a landscaper here can only give me input on how he approaches his business, not on any plantings. As for my personal gardening expertise: I seem to be able to kill plants in two different states with equal skill (or lack thereof). So, ages ago, I contacted a Master Gardener in Oregon. Neil was very helpful, but I really wasn't ready to ask too specific a question. Now I am, and hope to be able to reach him again, or find someone equally cooperative. Ahhh, research.

My favorite research email was from a city engineer in Portland, OR who gave me the rundown on the bridges in that city. He was a godsend, although I originally worried that he might interpret my email as being from a terrorist who wanted to clog up the city commute. Luckily, nothing untoward happened shortly after he sent his answer to cause him to notify Homeland Security. Sometimes writers ask weird questions. I'll bet if someone were really paranoid, mystery writers would show up on all sorts of alert lists for some of the stuff they research.