Hydroseeding

Before the Main House was built, a large area was excavated just north of the site to create a level space for lawn and parking at the "front" of the house. The excavation was done in May, 2004. In the 4½ years since, nothing has grown on the exposed slope (not even weeds) due to the highly compacted clay with veins of bentonite. Bentonite is useful for many things, but growing plants is not among them. (Note: the orange-tipped markers are guides for snow plowing.)

Fixing this problem has been a low priority since the most desirable views are out the south windows, looking across the canyon. It finally came to the top of our complex schedule of landscaping tasks; most of the other tasks will have to wait until things dry out next Summer.

One reason for dealing with seeding the slope this Fall was we wanted to do dormant seeding so next Spring's rain will get new growth started as soon as possible and will minimize watering needs (having been forewarned by our encounter with the Seed Nazis). Since this south facing slope will warmed by the sun all Winter, we needed to wait as late as possible to sow the seed to avoid early germination. Weather this Fall was unusually warm and wet, so we put off finishing the work until November 28 – over 4 weeks later than this sort of work is usually done.

Hydroseed slurry alone is not sufficient to make even the native grasses grow. It was necessary to lay down a thick layer of topsoil. The slope was high as well as steep, so the topsoil had to be "shot" from the trucks onto the slope.

The added layer of topsoil raised another issue: how do we keep it all from washing off the steep clay slope in a Spring thunderstorm? The solution (we hope) was to add extra tackifier to the hydroseed slurry and give it more holding power. A special machine sprays the slurry onto the slope. The ugly gray-green dye makes it easy to judge where and how much slurry has been applied; we did not intend to make it look like a lawn!

Following the belt and suspenders strategy, we had jute mats laid down over the slope. In addition to providing additional stability, they turned the color to a more appropriate Fall tan. Then, using dead branches we had collected from the property, we weighted the mats down so the wind will not blow them away. The slurry and mats will biodegrade over the next 2 years, after giving the grasses a chance to take root and anchor the soil.

In about 8 months, we will know if our strategy works.


December 3 – Ready for Spring – Just In Time