There’s nothing like writing to show you what you don’t know.

The other day I took two of my characters on a field trip. Rather, they took me. These are the same two, Shannon and Jackie, I blogged about last month in “The Importance of Place,” after they took me to the Gay Head Cliffs.

Shannon has lived on Martha’s Vineyard for decades. Sister Jackie has never been there before. Shannon is playing tour guide. (Come to think of it, there’s nothing like playing tour guide to show you what you don’t know — and also what you do. Shannon listens to facts and factoids coming out of her mouth that she didn’t know she knew. I didn’t know I knew them either.)

So we went window-shopping in Edgartown, where in novel time it’s Thanksgiving weekend so some shops but not all are closed for the season, then we strolled along State Beach. The sheer vastness of the ocean started getting to us, so Shannon and I simultaneously hit on the same antidote: “Let’s go to the Campground.”

In the Campground — formally the grounds of the Martha’s Vineyard Camp Meeting Association — more than 300 cottages sit on about 34 acres of land.

I’ve been to the Campground many times over the years, but never accompanied by these two characters. As we walked, the conversation they were having flowed in interesting directions, shaped by the narrow walkways and the colorful, cheek-by-jowl cottages.

The Pink House from the front

The most colorful, and by far the most photographed, cottage in the Campground is the Pink House so of course Shannon guided Jackie in that direction. When we got to it, I was glad we’d made the trip.

In my memory the Pink House stood apart from its neighbors, as if they’d startled at the sight of it and taken a giant step backward.

But it doesn’t. It’s on a corner, yes, but it’s nestled as close to its immediate neighbors as any other house.

Jackie then wandered around to the back of the house. The Pink House may be the most photographed cottage in the Campground, and maybe the most photographed building on Martha’s Vineyard, but I don’t believe I’ve ever seen a photo of its backside.

Pink House, rear view, with mystery plant

The trouble started when I got home and started to write. What the hell were those tall stalky things on the left? I wrote “tall stalky shrubbery” and knew immediately that I wasn’t going to let myself get away with that.

Like what if I were reading about a character running through a meadow noticing little white flowers and little blue flowers over there and hard orange berries over here? A little of that goes a long way. At some point I start to suspect that the author didn’t know the names of the things and didn’t care enough to find out. This subtly undermines my confidence in her knowledge of other things.

So I posted that rear-view photo on Facebook and asked for help identifying the tall stalky thingies. The first two friends who responded said it was hard to tell without foliage or flowers, but they thought it was probably rose of Sharon. Others thought privet, which I’d always thought was an evergreen but it turns out it comes in deciduous too. Trying to confirm one or the other was difficult because all the pretty pictures I found on the internet were of flowers; no stalks were visible.

Rose of sharon is currently in the lead.

Sturgis’s Law #6 says “Your writing will teach you what you need to know.” This is how it works. That particular scene may disappear from future drafts of the novel, but now I’ve a pretty good idea of what rose of Sharon looks like. Who knows where it will show up next.