As you set out to form the perfect dinner salad this summer, consider what greens you choose for your base. Though they’re all some shade of green, they’re not all equal, or even comparable, in nutritional value. In fact, the differences between iceberg lettuce and spinach, for instance, are astonishing. But you don’t need to have nutritional data memorized to make wise choices. A simple rule of thumb is to go for the darker and looser varieties. Not to pick on iceberg, or put any iceberg farmers out of business, but iceberg lettuce has some of the fewest vitamins and antioxidants out of all of your salad green options. It’s no coincidence that it also happens to be a very light green color and the leaves form a tight head – the exact opposite of what you should look for. Iceberg’s low nutrient count is due to its high water content, which equates to roughly 96%. Yet, for some reason it still remains one of our country’s most popular lettuces. Romaine, on the other hand, with darker leaves and a looser form, has much more to offer. And if you care about taste or texture, I’d say it beats out iceberg in those departments as well.

What is it that makes darker greens more worth your while? Vitamin K is at the top of the list – the vitamin that helps your blood clot, protects your bones and can even help prevent certain cancers. Then, there is folic acid (folate), a type of B vitamin that is necessary for healthy cell formation and is especially important for pregnant women. Vitamin A is another prevalent nutrient found in many greens. It helps improve eyesight and strengthens the immune system.

If you’re stuck on iceberg, all is not lost. The pale green does contain some nutritional value, just not much when considering the alternatives. Instead, try a mix of greens, whether you’re an iceberg fan or an all around green lover. It will allow you to experience a variety of nutrients, as well as tastes and textures. You can often find bags of mixed greens at the market, or buy a few different ones and experiment. I was pick a variety of greens from my garden when putting together a salad and it never gets boring.