Romaine lettuce is the term more often used in the USA to describe a Cos lettuce. Typically it is a tall lettuce with long slender leaves and at maturity forms an elongated cupped 'heart'.

The leaves have quite a prominent and thicker rib through the centre, are generally more robust with a unique crisp taste that differentiates it from other lettuce. When grown to maturity, the upper tips of the leaves close to form a heart, which consequentially excludes light, colouring the internals to more of a blonde green. It is these paler leaves that are most tasty, tender and desirable.

This type of lettuce is extremely popular due to the creation of the Caesar Salad. There are many interpretations of this recipe, but it most definitely should start with a cos.

How to prepare

Remove some of the larger outer leaves that are left on to help protect the lettuce during transport and handling - these are great to feed back yard chickens or put in the compost.

Trim off the lower end where there is a solid core, and prepare the leaves as necessary. The smaller inner leaves can be used whole as vessels for delicious toppings, or the leaves cut into bite sizes pieces in creating a salad.

Because the leaves tend to be more robust, they lend themselves well to being cooked briefly, usually flash grilled or stir fried.

Buyer's and storage guide

You'll usually find whole heads of cos loose on the shelves, or often in a sleeve. Look for leaves that are fresh and undamaged, also checking the lower part to ensure it is clean. It should also feel weighty.

Romaine lettuce can be stored in an open plastic bag in the refrigerator for about a week.


  • Create a salad with your choice of extras, using cut bite size pieces together with whole leaves to enhance presentation
  • The classic Caesar Salad - the heart leaves cut into small pieces and dressed with croutons, small bits of fried bacon, a ranch style dressing, anchovies and topped with segments of a boiled egg and shaved parmesan cheese
  • Cut the heart in half lengthwise, grill on a hot barbeque plate for a minute of so, and serve halves intact dressed with some olive oil, black olives and coriander
  • The cupped internal leaves make great edible bowls which can be topped with smoked salmon, creme fraiche, fresh dill and lemon
  • Great for kids to increase their vege intake by using the leaves as a substitute for a wrap with some thinly sliced capsicum, grated carrot, cherry tomato wedges and ham