Kames, Kettles, Cobbles and Stone Meal

Ah, it's so good to be living in glacial country again.  I grew up in another glacial place, south central Wisconsin, near the small glacial gorge at Devil's Lake.  It seems like home, although the scale here is much larger...mountains rather than hills.

Our Methow Valley, and the adjoining Chewuch Valley, where once filled with massive glaciers that extended 1000 feet down below the current valley floor.  Those glaciers slowly ground the underlying rocks, ranging in size from a car to a marble, into rounded cobble shapes.  The ground up material made a sandy loamy soil with various amounts and different sizes of those cobbles in it, at different depths, depending on where you are in the valley.  The result was what is called glacial till, as if the glaciers had tilled the land, totally transforming it.

Cobbles Steve sifted from a car-sized dirt pile

The glaciers also left behind their own unique collection of landscape formations of all sizes, shapes and orientations, that were superimposed on the larger, framing mountains and hills.  At our place, we have a series of low rises and a deep, round hole big enough for a house just outside our property boundaries. The rises are called kames and the holes are kettles.  They can be arranged in ways that you wouldn't see in a non-glacial valley and make for a whole new way of finding your way through a place.  Drainages don't always end up, or start, where you might expect them. Lakes and ponds can lie in surprising spots.  Massive rocks lie on the surface, all alone, with no apparent explanation for how they got there.  For me, all of this just adds to the charm of exploring this place.

Steve standing at the bottom of our kettle.  This one has no pond in it, unfortunately.

Each kettle was formed by a giant block of ice, the size of the kettle, that was left behind near the surface of the deep glacial till as the glacier melted away.  Some were lying low enough that the bottom of the kettle is below the current day water table, making a lake or a pond.  For a view of one of the larger kettles across the road from our house that has a lake in it, Little Twin Lake, go to Methownet.com/grist/features/twinlakes.html.

The glacier left behind a huge storehouse of material to work with, if you have a mind to build a garden.  Or, you can look at it as an immense headache.  If you see it this way, I would advise setting up your garden in another part of the state, or looking hard for those places in the valley where the soil is almost cobble free.  (We wanted to live closer to the amazing trail network near Winthrop and Sun Mountain and were willing to put up with the cobbles.)

Looking back at our place from the kettle.  Look at all of those rocks.

For me, the most magical gardening component of this kind of soil is the fine "glacial dust" it contains, full of minerals from rock sources as far away as Canada.  (Which is only about 30 miles north as the crow flies.)  In the late 1800's, a German miller named Julius Hensel used the fine stone dust that came from his stone grist mill on his garden.  He found that plants responded to it with extra growth, vigor and health and provided more produce.  He called the dust steinmehl, or stonemeal, and promoted it as the next big discovery in improved farming and food quality.  His book Bread from Stones is still read today by those who are looking for the best way to produce nutrient-dense food for better human health (although he is missing out on the importance of the organic material in the soil, it seems).  Unfortunately, he was up against the emerging opposing view that plants only need water soluble nitrogen, potassium and phosphorus to grow better.  This approach did make for faster and larger growth but did not produce stronger plants or produce of higher quality.  It was easy to scale up production and easy to apply, and quickly outpaced the early attempts at mineralizing the soil.

The discussion about soluble chemical versus mineral dust approaches, among agronomists, farmers and serious food gardeners, continues today with growing interest in the importance of soils having dozens of different kinds of minerals and elements.  The push is on to understand how these components should be balanced in the soil to produce health-promoting food.  Today's term for this is "remineralization" and is even being researched by the USDA, as well as a number of dedicated private individuals.  One strong local northwest regional advocate is Michael Astera, who offers soil remineralization prescriptions based on your soil tests and provides needed minerals for sale in amounts  that are right for home and small production gardeners, farmers and orchardists.  Check out his web site at soilminerals.com.  You can also look at the "Remineralize the Earth" site for the bigger hype.

The exciting thing for gardeners living in post-glacial country is we have a lot of native stone meal to work with in our soils.  The glacier did the hard work of grinding the minerals much finer than can be done cost-effectively, commercially; and we just need to add in some of the minerals that the parent material has too little of.  In this area, that might be some boron, potassium or phosphorus in fine rock dust form, and other trace minerals.

Using Michael's prescription for my Rockchuck Ranch garden, I amended 1000 square feet of new garden beds before planting them this spring, and will see what happens.  The results can be measured by a new soil test this fall, or by nutrient testing that is becoming available for garden produce through a service related to the remineralization groups, or by testing the sugar content of the produce known as the brix level.  I'm going to be looking into how to do this and will keep you posted on any results I might get.

My freshly dug garden beds.  Thanks Steve for helping with the grunt work

Critics comment on the need to mine faraway sites to provide minerals that are in short supply in different areas.  They point to the cost and environmental damage of mining and shipping minerals.  But, I think this needs to be compared to the environmental damage and health concerns from NPK-based soluble fertilizing, and the benefits of nutrient-dense food from mineralized soils.  The goal is to have a broad supply of natural minerals in the soil that micro-life can work with to maintain the right balance for soil life and plants over many years.  (More on this to come.)

I've just touched the tip of the glacier here, but hope that I might have interested some of you in an important aspect of food growing, remineralization.  I'm going to continue to experiment with this exciting approach that is being rediscovered from the 1800's by people concerned with how to grow really healthful food.

Kate