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Plants and Stone for California Gardens

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Sinkhole!

The presidential sinkhole wasn’t the only pit to open this year. One of my gardens had a sinkhole too, even huger than his. It happened in a garden I planted a few years ago. A culvert runs along the property line carrying storm runoff from the street out to a creek behind the garden. A lot of water was going into the pipe every time it rained, but it turns out PG&E had accidentally punched a hole in that pipe and so the water was running underneath the pipe instead of inside it, carrying away the soil and forming an underground gully which eventually turned into the sinkhole. No one was hurt when the sinkhole opened, but a large section of fence collapsed and a mature oak tree moved six or eight feet from one side of the property line to the other and had to be removed. Pretty scary to think of an oak tree moving so far, it was tall enough to fall onto the house.

The sinkhole was especially frustrating because we’d noticed the problem a couple of years earlier and submitted an engineer’s report to the town and utilities to try to get someone to address it. But it would have been expensive and a hassle to fix, so, unsurprisingly, no one wanted to take responsibility and nothing happened. Of course, in the end it was even more expensive to fix and an even bigger hassle and we lost the oak tree. Though to be fair, I don’t think anyone was expecting a giant sinkhole.

This is my nearby planting — the two furthest sections of fence in this photo are the rebuilt sections of fence that collapsed, the Loropetalum in the background is about six feet from the edge of the sinkhole — looking relatively unaffected by all the drama beside and below it. The underground gully extended underneath this planting and several tons of concrete were pumped under here to fill it. But it always stayed like the calm surface of the water, not showing the currents below. The plum trees are probably the only ones with roots deep enough to reach the concrete.

A side note, this garden is the home of the basalt pieces I used as a kickboard in the garden show a few years ago. They’re not especially noticeable while the Nepeta is blooming, but they’re pretty unique, two nine foot long sections of basalt to edge the lawn. It might be interesting to do a post showing where all of the garden show materials ended up.

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