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Archive for May, 2017

Lawn Conversion with a Cover Crop Phase

This is a lawn conversion we did a couple of years ago. Usually we convert lawns by leaving the lawn in place and covering it with sheet mulch. I’ve posted about the process in the past. This one was a little different. When I first got involved, most of the lawn had already been removed by hand. The client had also decided to do a cover crop for a season to regenerate the soil. Generally, I think that by sheet mulching, the decomposing lawn will accomplish pretty much the same thing as a cover crop. But a cover crop is certainly another effective way to do it. This lawn had tired, depleted soil, and several Mulberry trees had roots everywhere that would compete with the new plants, so I’m sure the cover crop was beneficial.

We used vetch as the cover crop. We seeded it just after Thanksgiving, gave it about five months to grow, and then removed it at the end of April. There are a few ways of dealing with the vetch. Most of the research and info about it is geared towards agriculture, and my experience with it was for lawn and veggie garden projects rather than ornamental plantings. For the lawns and veggie gardens, I had tilled it directly into the soil. For this garden, to avoid disturbing the roots of the mulberry trees, we left the roots of the vetch in place and tore off the tops of the plant, chopped those tops a bit, and spread them on the surface to rot beneath the fir bark mulch. Supposedly that gives less nitrogen gain, but the layer of vetch helps retain moisture in the soil. I don’t really know, there are too many variables to conclude anything other than that the planting did well enough with this method. I’m still partial to sheet mulch and generally still recommend that method, but I’d be happy enough to do it again this way. Seeing the vetch grow throughout the winter was fun, and rolling it away in the spring went quickly and was actually kind of fun too. I was worried the vetch might reseed itself and make a mess in the new planting, but as far as I know it hasn’t been a problem. The photo below was when we were half way through removing the vetch.

Above shows the new planting with the dried out vetch hidden beneath the fir bark mulch. Below is what it looks like now after two years of growth. This, with the Bearded Iris in bloom, is the showiest the planting gets. They’re pretty much the biggest flower I know that won’t get eaten by deer. Next month there’s a fair bit of Teucrium, Linaria, and Verbena to bloom, but those make a lot of little flowers. For this garden, I like seeing the fist-sized purple flowers.

Below is the view of the garden from the other direction, starting with google earth’s view of the lawn, then the space after the lawn was dug out, with the vetch growing, and how it looks this spring.


As I said, I was worried that the vetch would reseed and make a mess the next year, so we removed the vetch bfeore it could set seed, and we also spread corn gluten seed inhibitor throughout the planting as well. I don’t know if the corn gluten made an impact or not. I use it sometimes but have never had a control group to compare and decide if it is actually effective.

As part of the new planting, we made a path and a seating area, the client had some chairs that we put around a boulder with a sawed off top. The photo above is the view from one of those chairs. So much nicer than a tired old lawn.

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.

Sharpie Lithography

During the week I’m staying at a house in Richmond that doesn’t have internet or cell reception, which is probably a healthy thing overall, but a distinct hindrance to blogging. I still have several stone posts from Oaxaca to do, but spring garden season has swallowed me up and I’m going to shift to that. Stone is timeless, so I can post them later this year at some point when I need to imagine myself back on vacation. In any case, it’s been a busy spring with lots of gardens looking good after all the rain.
Before I get to that, this photo shows a stone that I’ve been carrying around in my truck to weigh down tarps. I left it at a job site over the weekend and came back to find it had been appropriated into the oevre of a six year old artist during my absence. Modern in its conception, I see echoes of Basquiat, maybe a little Cy Twombly or even Jim Dine. Definitely the most charming thing to greet me at a job site in a while.

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