Ice Cream & Frozen Treats

What's more refreshing than an ice cream cone on a warm summer's day? Nothing. But it's safe to assume, that ice cream will be more soup than cool treat by the time the dessert is being served. Skip it for the potluck.
Deli Meats

While it's questionable if lunch meat every actually spoils, there's certainly a good chance you'll find out if you bring deli meat for sandwiches on your next picnic. Plus, meat sweats in the sun, and you should be the only thing sweaty at your summer picnic. Ew.
Foods That Are Hard To Cut

Picnics usually mean lunch is served on laps, not tables. That means hard to cut foods should get cut from the menu. It's just too hard to cut through tough foods when you're standing or seated on the ground. Plus all those sharp blades around children and the elderly.
Deviled Eggs

All that mayo that goes into deviled eggs makes them totally delicious—except when they sit in the sun and are rotten by the time you get to eat one. Stick to hard-boiled eggs if you just have to have an egg at your summer picnic.
Potato Salad

Mayonnaise is quick to rot in the sun. So is potato salad and any other mayo-based food that requires refrigeration. Search for a vinegar-based potato salad recipe. Or skip it all together for a crudité platter.
Sushi

It's bad enough to leave a picnic with a bee sting. It's worse to leave with food poisoning. Raw fish requires refrigeration and there's just no way to keep temperatures steadily cool when you're outdoors for hours. So leave your sushi craving for another time, a time with a sushi chef and a refrigerator. You'll be thankful you did.
Soup

Unless you're bringing a chilled soup (and then there's still the mess/spill factors to deal with), hot soup on a hot day isn't exactly what everyone craves. And if your hot soup does stay hot long enough to be enjoyed, there's a chance it'll turn into a dangerous hazard when someone at the picnic spills soup all over the place. Ouch.
Cheese Plate

If you must have a cheese plate, stick with hard cheeses. Those soft cheeses will turn into soup, and a potential stomach ache, real fast.
Soda

Not only does soda get super sticky when spilled, which it will be at a picnic, but bees and insects are drawn toward an open soda. That means those bees will be drawn to whomever is drinking that soda. Nope.
Fried Foods

Not all foods travel well. Fried foods are one of them. They get soggy fast, which is never a good thing.
Chocolate

Before you will have gotten out of the car, all that chocolate you packed for the picnic will have melted. Leave the chocolate at home where you can keep it cool. Plus that way you don't have to share! Bonus.
Pizza

Unless you're going eat that picnic pizza real fast, it's going to get melt'y and soft. So if you don't like a crisp crust, maybe it's no big deal. Otherwise, there's plenty of food to bring to a picnic that isn't a pizza.
Fruit Salad

Fruit salad seems like the perfect picnic item until you bring the bees with it. The only thing that'll love all that sweet fruit more than you will are the zillions of bees hanging out at your picnic. There's a reason people always bring a watermelon to a picnic. So leave those sweet berries for another time and break out that watermelon. Yum.
Soft Fruits

If you like smashed fruit, definitely pack a bunch of plums, peaches and pears. If you don't, and you probably don't, then don't.
Oysters & Raw Fish

Oysters, shrimp cocktail, crab legs and any raw bar ingredients should be kept on ice and shouldn't sit in the sun. And since most picnics take place in the sun, it's safe to assume that a raw bar is clever for a picnic but not too practical.
Tuna Sandwich

Not only does tuna rot fast because of all the mayo, it also gets super soggy. So while a good idea in theory, not a great picnic food in practice.
Green Leafy Salad

Though it might be fun to play "Guess How Long It Takes For That Green Salad To Get Soggy" at your next picnic, it's probably not that fun to eat that soggy salad. If you must bring a leafy salad, don't add the dressing until you serve the salad or you're definitely going to serve a green, mushy mess.
Cole Slaw

Cole slaw seems like a picnic go-to, except for the fact that it's filled with mayo, which rots super fast. So if you're dying to picnic with cole slaw, try making the kind that doesn't require mayo. It's probably healthier that way anyway.
Anything With Whip Cream

Whip cream is another quick-to-spoil food. So, if for some reason you must serve it, make sure to keep it in a cooler until it's go time. Or buy one of the many non-dairy whipped toppings in the freezer section. Otherwise, expect to whip up some serious stomach issues.
Food That Requires Two Hands

Unless you're bringing a picnic table to your picnic, or you know there will be one on site, it's safe to assume guests may not be able to eat food that requires two hands since they'll be holding their plate or drink. So keep food simple, easy and easy to eat.