Everydayhealth.com suggests a healthy idea is to get more variety into the salad bowl

Brigid K. McVaugh, MS, RD, LD, a clinical dietitian at St. Luke's Episcopal Hospital in Houston, said all greens have something to offer, "where they differ is in the vitamin and mineral content."

Read on to find out the benefits of:

Butter lettuce — including both Bibb and Boston lettuce varieties — has a soft, buttery texture and a slightly sweet flavor. It has a tightly folded head that is bright green on the outside, yellow on the inside, and is often sold with the roots attached to preserve freshness. Butter lettuce is low in sodium, a good source of vitamin A, and has small amounts of iron and calcium.