Rocks and Stones

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photo-15
rich rock greenhouse 2013
rich rock greenhouse 2013

Last weekend, my brother Rich and I dug the last bed in the greenhouse which was yet unplanted, so we could transplant a row of eggplant seedlings.  In the process of digging the 3' wide by 40' long bed, about 18 to 24 inches deep, we unearthed these rocks.  Here he is in front of the rocks and again in front of  the dug bed.

Vegetables don't like rocky soil.  Their fragile roots have a hard time getting around them.  Like hitting the proverbial block wall.

Last year we rototilled this area and turned up about this many stones.  I guess we missed these, because  I know they didn't "bubble up" like most of the stones in New England, since this area was inside the greenhouse over winter, and the ground never froze.  The freeze-thaw cycle in the ground causes the upward motion of rocks, typically about 1/4 inch per winter.  But if the ground doesn't freeze, there is obviously no upward force on the rocks.

New England is well known for its miles and miles of stone walls surrounding most of the countryside, made from stones which bubbled up from the ground.   But it wasn't always that way.

These stones were deposited by glacial movement during the last ice age, thousands of years ago.   The southern edge of the glaciers formed Cape Cod.  After the glaciers retreated, vegetation returned, and New England eventually became forested, nearly 100 percent.  When the colonists arrived, there were very few stones in or on the topsoil.  However, by about the beginning of the 19th century, New England was almost completely deforested.  The early colonists needed wood for buildings, fences, ships, barrels, firewood, charcoal (for early industrial blast furnaces), and so on.  They also needed cleared land for farming.  As the forests were cleared, the topsoil was primo- very rich from the eons of natural composting of leaves and other organic matter.  And no stones either.  The ground does not freeze very deep in the forest, like it does in open fields, so none of the buried rocks were apparent for quite a while.  It wasn't until after the Revolution that most of the rocks started bubbling up.  But once they started, they never stopped.  Most of the stone walls were built in the late 1700's and early 1800's.  Because the soil had been so pristine for so long, and generally having no geological knowledge, many farmers believed they had been cursed by God.  Around this time many of New England's farms had transitioned from subsistence to market farms, and many of the farmers reasoned that it would be much easier to move to the midwest where the soil was stone-free, than deal with the hassle of the stones.  Little known fact:  New England's stones were a big factor in the country's western migration.

I've always found it interesting that as rocks bubble up, they generally look about fist-sized.  Many are like icebergs though, mostly submerged.  Sometimes they come up easily with only a shovel.  Sometimes, after digging a bit, I realize how large they are.  Then I get the tractor or excavator.  Some are so large that even big machinery can't pull them out, and they need to be re-buried as deep as possible.  I can empathize with the farmers of a couple hundred years ago giving up and heading west.  It's hard to imagine dealing with car-sized rocks with only oxen or horses.

So , back to the title of this post:  Rocks and Stones.  I generally have a negative connotation around the word "rocks" and a positive connotation around "stones".  Not sure why.  For the negative, maybe because of the saying "He has rocks in his head."    For the positive, I've always loved the aesthetics of a well built stone wall, stone house, stone chimney, or stone fireplace.   At any rate, we've been trying to turn all the rocks we dig up into stones.  Like turning lemons into lemonade.

We turned up quite a few a couple years ago when we planted our fruit trees.  Initially, we didn't know what to do with them, but about that time I read the book Permaculture, by Sepp Holzer. He grew fruit trees successfully at 4500' elevation in the Swiss Alps when all the conventional orchardists said they wouldn't grow above 1500' elevation.  Turns out that the ones he had that did well were planted near large stones.  The thermal storage of the stones created a microclimate that allowed the fruit trees to grow outside their normal range.  That inspired me to build these stone cairns around our new fruit trees to hopefully help them get through a few New England winters, long enough to get well established.

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IMG_5659

More recently we used some of our larger stones for a more traditional purpose, building the retaining wall around our new lean-to greenhouse for citrus and avocado trees.  Ron Tinker, our right-hand man, built this stone wall with an excavator.   I like it a lot.  It really anchors the building.

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IMG_6246

Currently he is using our excess stones to build a road through a particularly wet and muddy area back into the woods where we've begun a tree coppicing program to sustainably feed the biochar retort.

Rocks and stones.  Trying to find as many creative ways as we can to turn rocks into stones.

Steve