Add shredded butternut squash to your favorite carrot cake recipe.

They may look weird or scary, but don't be afraid. Winter squash — those hard-shelled varieties showing up in stores and farmers markets — are chock-full of vitamins, nutrients and flavor.

Why are they called "winter" when they grow in summer? Because these squash (unlike their thin-skinned cousins) can keep for weeks, even months — without refrigeration.

Winter squash retain their sugar (and sweet taste) longer when stored at room temperature. Chilling actually degrades the squash. When they're refrigerated, their sugar can turn to starch. Recent University of California, Davis, and Oregon State University studies showed that most winter squash preferred storage at 50 to 59 degrees, with moderate humidity and good ventilation. Any colder and they went bad rapidly.

California ranks among the nation's leading producers of winter squash (including pumpkins), second to Florida. And we're eating more squash, usually fresh — up to 4.2 pounds per person per year. Americans average about 1 pound of canned or processed squash per year — mostly pumpkin or baby food.

Some varieties of winter squash are so pretty that they're used more for decoration than food. But try some on your plate — you may be surprised.

With relatively few calories, winter squash is high in beta-carotene. That's why it has that great orange color.

It's also high in fiber and dense with other nutrients. In general, the darker the squash, the more vitamins.

A half-cup of mashed acorn or butternut squash has 60 calories, but three times the recommended daily allowance of Vitamin A. It's also high in Vitamin C and cancer-fighting phytonutrients.