Romaine lettuce develops long heads of leaves with heavy midribs. It has a crisp, sweet flavor and adds crunch to a salad. Spinach is characterized by a compact rosette of leaves that may be crinkled or smooth. It also can be used as a cooked green or potherb. Thin the plants several times using the thinned seedlings in salads and mature plants as cooked greens.
Radishes also are popular in salad mixes or by themselves.
Radish roots vary in size, color, shape and texture. White 'icicle' types tend to be slightly more pungent and take longer to mature. Both should be planted early and kept moist. Heat and water stress will result in pithy, highly pungent roots. The most popular type is the traditional English pea.