Thursday, March 11, 2010

When The Frost Leaves The Ground

Wild Plants And Wooly Bears

The piecemeal manner in which frost leaves the ground in spring fascinates me. At first glance, it seems natural enough to assume that the process occurs uniformly and gradually. But in fact, it doesn’t happen that way at all.

Of course it all depends upon how deep the frost has gone in the first place. And that, depends upon whether the ground was wet or dry, covered or bare and also, the type of ground, such as clay, sand and so on.

For starters, places that we keep open by shoveling have the best chance for frost to penetrate deeper than spots that were continually coated with snow. For instance, I always shovel the walk from my house to the greenhouse. When frost begins to leave the surrounding ground, the land appears to sink. But the shoveled area rises. This makes for a very uneven surface and difficult walking.

Other parts of my lawn are wet and others are bone dry. These, too, exhibit heaving and settling to varying degrees. To view such scenes, it seems impossible to imagine that in a few, short weeks, the entire area will be level…or, in the case of my lawn, sort of level.

All this brings to mind the frost heaves on our rural roads, “thank-you-mam’s,” that cause motor vehicles to leap into the air and come down with a bang. There are solid reasons why some parts of roads heave and others don’t. Refer to the second paragraph above.

I’ll end with a question, something that has always puzzled me. Why do they put warning signs on insignificant frost heaves and minor bumps, all the while leaving the truly huge ones unsigned?

No comments:

Post a Comment