It's the final days of August and I confess that I'm ready for the fall. I've become watchful, alert to subtle shifts and signals: the changing light, the shorter days, a touch of something in the air. This morning, in the courtyard out my back door, I notice that a few of the green apples on my neighbor's tree, the ones that are up high and facing south, have taken on a touch of rose. Around the corner, the persimmon tree sags under its load of hard fruit, grown to the right size but still firm and a deep, unripened shade of green. In the market, I keep a keen eye out for the first of the winter squash even as I'm filling up sacks of bargain-priced, summer-glut tomatoes.