Pecan-Crusted Cod (Deb Lindsey/FOR THE WASHINGTON POST)

Pecans are nature’s last generous gesture before the frigid arrival of winter. When other tree crops have been exhausted, the pecan harvest is still going on — in some places, into December.

The pecan is a quintessential American nut. It’s native to North and South America; surprisingly, its popularity hasn’t spread much beyond there. That might be changing, says Kathleen Purvis, author of “Pecans” (University of North Carolina Press, 2012). “They’re becoming very big in China.”

Pecans are fresh right now, though possibly not in their usual abundance. “The supply has been very tight the last couple of years,” Purvis says, a result of drought and other climactic extremes. But Georgia and Texas, the two biggest pecan-producing states, report improved harvests this year.

For best storage, Purvis says, buy pecans in the shell and crack them out as needed. They’ll keep for a year that way. Or shell them, wrap them tightly and stash them in the freezer, where they’ll last for years, she says.

RECIPES:

Frozen Fruit Salad

Wheat Berry Salad With Oranges, Cherries and Pecans

Cider-Braised Cabbage With Apples and Pecans

Fig and Pecan Tapenade With Goat Cheese

Pecan-Crusted Cod With Rosemary