Sometimes, it’s hard to tell. Are those colorful gourds and funny-looking vegetables you see in grocery stores and at farmers markets to eat or make into a centerpiece for the table?

If you’re using them only for a wreath on the front door or to decorate the mantel, you’re missing out on great foods that pack a nutritional punch.

That LSU-purple kohlrabi or rutabagas and those gorgeous green Brussels sprouts and mirlitons may not be mainstays at your table, but they should be.

“As a rule of thumb, the more colorful it is, the better it is to eat,” says Renee Puyau, a registered dietitian with Pennington Biomedical Research Center.

Colorful fall vegetables offer a myriad of vitamins and antioxidants vital to every diet.

For example, the many varieties of squash not only add a splash of color to your table, they’re very good for you, says Pennington dietitian Whitney Yarbrough.

“They are packed with nutrients, such as beta-carotene, which is beneficial to the skin. They also contain vitamin C, which helps boost our immune system and which also acts as an antioxidant to prevent or delay some types of cell damage,” Yarbrough says. Squash are low in calories and fat and offer untold opportunities to create delicious dishes.

Dietitians from Pennington have been developing healthy recipes based on produce available at farmers markets this time of year.

Most of the recipes are at Pennington’s website, pbrc.edu, and are updated as produce seasons change.

Here’s a primer on fall’s produce stand.

ACORN SQUASH: It’s easy to see where the name comes from — it looks like an oversized acorn. This squash has a deep green color with a light orange flesh that is sweet and delicate. It can be served savory or sweet, and its bowl-like shell is perfect for stuffing. The exterior is edible, so no need to worry about peeling it.

BRUSSELS SPROUTS: Low in calories, high in fiber and plenty of antioxidants, these “mini cabbages” have become more popular in recent years as restaurants have begun to offer them as an alternative to traditional green beans and broccoli. The miniature size makes them easy to prepare, and they are best cooked by steaming or roasting. Brussel sprouts are great combined in moderation with salted meats, such as bacon.

BUTTERNUT SQUASH: This squash has a pale orange exterior and bright orange flesh that is buttery, sweet and slightly nutty. Butternut squash is probably the most familiar to consumers. It is easy to prepare and can be dished up in a variety of ways.

SPAGHETTI SQUASH: This bright- to dull-yellow gourd gets its name from the texture of the flesh, which, when cooked, resembles spaghetti. It has a very mild flavor and can be used as a pasta alternative.

RUTABAGA: This large root vegetable has a flavor that’s a cross between a cabbage and a turnip. It is sometimes called a Swedish turnip. It has a sweeter taste, is high in Vitamin A and is often steamed, baked or shredded and eaten raw in salads.

KOHLRABI: OK, we’re just going to say it. This fall vegetable looks weird — like an onion with tentacles. The bulb can be pale green or as purple as a Tiger’s jersey. Also a member of the cabbage family, it has a peppery sweet flavor. The name is German, meaning “cabbage turnip.”

The root is what is usually eaten, but the entire plant is tasty, especially in stir-fried dishes or chopped up in a salad. The smaller the bulb, the sweeter it will taste. If the skin feels too thick, it can be peeled until you get to the crisp layer; otherwise, leave it to cook. The bulb is great raw, shredded into slaw or sliced and served with a dip. Kohlrabi makes delicious fritters and can be roasted. It’s a good substitute for mashed potatoes or cauliflower.

TURNIPS: Depending on where the root was exposed to the sun, turnips’ bulbous root can be purple, red or greenish. The leaves are turnip greens, and their cooked flavor resembles mustard greens. Turnips can be used interchangeably with potatoes. The texture will be different, but they are lower in calories and higher in fiber. Turnips are a good source of protein, iron, magnesium and all the phytochemicals (color) provide beneficial antioxidants.

PARSNIPS: These root vegetables look like white carrots. They can be baked, steamed boiled, sautéed, mashed or grated and eaten raw. Just about any recipe you have for carrots will work for parsnips. They do not contain Vitamin A or beta-carotene, like carrots, but they do contain vitamins C, E, K and B, as well as potassium, calcium, iron and other minerals. They are a good source of fiber and contain antioxidants. Surprisingly, parsnips contain more sugar than carrots.

PUMPKIN: No stranger to fall produce aisles as a fall decoration, pulp from smaller pumpkins can be just as delicious as the canned stuff. Pumpkin seeds can be roasted and salted, and the orange and yellow colors mean they are high in beta-carotene and vitamin A, a boost to healthy eyesight. A warning: the innards of your front porch jack-o’-lantern will be too watery and tasteless to use. Look for pumpkins about 6 to 8 inches tall, usually labeled as pie or cooking pumpkins.

MIRLITON: South Louisiana’s vegetable pears, the “mel ay taw” or “mil e taw” if you’re from rural parts or the “mirl uh tahn” for city folks, this squash belongs to the same family as melons and cucumbers. It’s high in fiber, low in calories and a good source of vitamin C. Also known as a chayote squash, it’s traditionally served stuffed with seafood and is common on holiday tables.