Visiting Roxhill “Bog”
Published at 20:03 on 9 January 2012
At the headwaters of Longfellow Creek in West Seattle is what used to be an extensive peat bog. It was then partially mined for peat, filled, and turned into a park. Except that much of the park never was very successful, because it was still in a low area and its lawns tended to be mushy and squishy. Worse, there was still peat under all that fill, meaning the land had a tendency to subside.
So about 10 years ago, it was decided to try and bring the bog back, at least in the lower part of the park. Except that it’s no longer a coniferous forest in the surrounding area; it’s mostly lawns. Lawns that get a fair amount of lime and fertilizer dumped on them in order to keep them healthy.
Alas, what keeps a lawn healthy is the same thing that kills a bog. Bog plants can cope with extreme acidity and low nutrient levels just fine. What they cannot generally cope with is non-bog plants, because the latter grow faster and out-compete bog plants in non-bog environments.
And so it is that, ten years on, the “bog” is not really bog at all; it’s an open, marshy wetland in the process of evolving into a forested, swampy one.
Wetland (as opposed to bog-specific) plants were in general doing just fine. Swamp roses were growing in great profusion, and black cottonwoods and willows were volunteering everywhere. The Sitka spruces which had been planted generally looked very healthy.
However, most of the specific bog species plantings I found were sickly and barely surviving. There were a fair number of stunted bog laurel bushes, and an even smaller number of very sickly-looking Labrador tea shrubs. Hardly any of the bog sedges remained; invasive grasses had pretty much universally displaced them. Sweet gale was an exception to this rule; I saw a number of vigorously-growing, very healthy specimens, which had obviously spread significantly to form large clumps since they were planted.
It was, in total, less of a complete weed patch than I had expected. Perhaps there’s enough remaining bog acidity in the soil there to keep a damper on the worst of the weed overgrowth.
Sorry, but I don’t have any photos to accompany this article. I did have a camera with me, but I spaced and forgot to use it.