Landscape Rocks & Boulder Month – Rounded River and Glacial Rock | Steve Snedeker's Landscaping and Gardening Blog

I typically have worked with 3 major categories of rocks and boulders in the landscapes I have designed and installed. Since I am newly-arrived in Kentucky, the more “Eastern U.S.” types of boulders and rocks – the Shales and the Limestones – have not been much in my headlamps. I truly admire their potential as the prior post points out. Particularly the limestone slabs interest me, with their horizontal possibilities. The list of more Western boulder types is this:

1. Rounded River Rocks, smoothed by tumbling under glaciation and running water

2. Fractured basalt rocks, into which I include “Glacial Schist” – also included in the Basalt rock column would be the pillars and crystalline rocks of basalt origin

3. Igneous rocks of particular individual merit……….and I guess I could include Fossilized Rock – ‘petrified wood’ – as well, since I have actually used it in landscapes.

River/Glacial Boulders

I find these multi-utility rocks. They come in large numbers, very naturally. Aside from how we view the West, it was real wet at one time, with glaciers advancing and retreating, big boulders and small ones tumbling under mile-thick coverings of ice. As well, many rocks sat under water and the incessant pounding of running water rounded them off into interesting and sometimes literally circular shapes.

In landscaping, I like using these for water features (insert “duh!”), owing to the natural affinity with water in all its guises. I use them also for constructing artificial creek beds which double for a site as drainage trenches, moving rainfall and snow melt off the property and directing it where we want it to go. These are a delight to construct:

We assume the most natural effects in making these. Notably, for example, water will encounter an obstacle – such as a large rock – and find a way around it, thus the curving parts of my artificial creeks have larger boulders at junctures where the bends take place. We also try and find what would be a natural course, including its origins. When things make sense, the senses agree.

As can be seen above, I also use these to solidify a hillside as well. Inserting boulders does indeed help with erosion control, sitting all hefty and attractive, they supply ideal locations for planting as well as for diverting tides of water.

The picture below has a bunch of grouped boulders “Keyed” to prevent an erosive collapse onto what will eventually become an expensive and very long concrete driveway. They retain a secure place, especially when we add channels to it which will direct the water away. Nevertheless, this being such entirely new, basically ‘sculpted’ and not very compacted terrain, and composed of soft, dusty, silty material, we did what we could to avoid future problems. It turned out, the first year, we were glad we did.

And we play, too, attempting to make remarkable pieces of art out of our soil and rock sculptures. For example, on this same property, we made sets of stairs out of large, up to one ton boulders, in two different locations. These stairs are not for everyday traffic but they were still functional, keeping one’s shoes out of the dirt and garden – the intent of any garden pathway.

The steps are on the right in this picture. If you enlarge it, you can far more detail and I am really not all that at editing pictures to show the features I want most to focus on. I just take them.

The above picture is taken at the bottom level, just as Spring had arrived and in time for us to address the disasters which a 100 year rain event had caused. We were more than a little glad we had taken what steps we did take to minimize erosion damage. It could have been worse. This project was about 6 months old at this time – in construction terms, from when we began.

This is another level up, between the home itself and a huge garage where garden tools and an RV shed are located. The stairs here are obviously on the right.