Guidebooks are good for planning where to go, and when if its just about the weather. But every now and then I stumble on something that I wished someone had warned me about but seems to fall between the guidebook spines in terms of practical information. Like tree pollen.

For example, I am mind-bendingly allergic to eucalyptus trees in bloom (or whatever you call it when the pollen flies). I know this because on a trip to San Fran a few years back, a friend near Berkley took me hiking. We drove north on Highway 1, pushing her little “I think I can” to its best Lexus commercial imitation. We planned to walk a few miles near the shoreline, through the trees, starting by the water.

I don’t think I made it half a mile. My chest squeezed. My nose ran. My eyes watered like I wasn’t just cutting onions but grinding my eyes with freshly-cut halves.

We turned back. I showered, napped, and still felt like a cold the size of the entire state had taken residence in my sinuses. Back in the city, I felt a little better, but it didn’t disappear entirely until I was somewhere 40,000 feet over Illinois.

It happened this weekend back home too, on Maryland’s Eastern Shore. The pollen was epic. Within an hour of pulling into the driveway Michael’s gray car was yellow. The air held a yellow tint. Really. It was a particle fog coloring our view across the street.

They don’t talk about that in the guidebooks.