Lettuces are often divided into three main groups: loose-leaf, head, and romaine ... red mini-head lettuce with a green heart ...

Varieties can have green or red leaves and can be used in ... lettuce Grown least often by home gardeners, romaine lettuce requires a longer growing season and many varieties are not heat resistant.

Keep in mind that darker red leaf varieties won ... robust and crispy romaine lettuce, and varieties of mild loose-leaf ...