Start thinking pecan pie.

The folks who make just about all the canned pumpkin in the world are reporting that this year's harvest was so poor that we're going to see the impact on our grocery shelves this holiday season.

Libby's says heavy rains during the 13-week harvest in Morton, Ill., -- pumpkin capital of the world -- frustrated efforts to collect all the pumpkins. That, on top of a poor growing season.

"Libby’s has been part of [the holiday pie] tradition for more than 80 years and we appreciate that honor," said vice president Paul Bakus. "That's why we wanted to alert bakers to the anticipated shortage.

"Our calculations indicated that we may deplete our inventory of canned Libby's pumpkin as we approach the Thanksgiving holiday."

There was a shortage of pumpkin in August and September, too, when Libby's typically relies on surpluses from the previous season. But 2008 wasn't much of a year, either, and home cooks started noticing the empty spots on grocery store shelves.

Libby's, as reported here on Garden Variety, seemed confident that the 2009 harvest, which was scheduled to roll into the stores by the end of September, would take up any slack. But the rainy fall made it impossible for the heavy trucks to get into the fields.

The longer the pumpkins sit in the field, the poorer the quality, said Libby's, and the company is considering simply plowing the remaining pumpkins into the fields to enrich the soil for 2010.

Meanwhile, Giant, Safeway and Wegman's in Maryland report enough canned pumpkin on hand to make it to next Thursday. Giant, in particular, anticipated the shortage and contracted for other brands.

For a look at a Libby's tractor stuck in the mud, keep reading.