New York Times: THIS past winter was a tough one in our backyard. Where we live, about a hundred miles inland from the South Carolina coast, winter is normally a good time to make changes, like the swath of turf I removed from our front yard this year and replaced with perennial flowers and small tufts of native grass. But what is normal now in the garden? One week I’m sweating, the bees are buzzing, buds are breaking; the next, the birdbath is frozen and there’s snow on the ground. Time and again, I found myself…