Lettuce Plants - Little Gem Easy to grow, a deliciously sweet compact variety. Little Gem is the perfect Cos Lettuce. It is quick to mature, dwarf and compact, producing crisp, sweet, medium-sized hearts. A Cos variety, these lettuce plants are resistant to root aphid. Good under cloches, the Little Gem is the ideal addition to raised vegetable beds or beds and borders. RHS Award of Garden Merit winner. Quick and easy to grow, lettuces are many peoples first veggie crop. Try mixing red and green lettuce leaves to add a note of bitterness to salads. Or try slicing up little gem lettuces and sautéing with peas and garlic for an alternative homegrown lunch.