There are four categories of lettuce: crisphead, cos (Romaine), butterhaed, and loose-leaf.
Sow from early spring until the first frost. Sow in rows 30 cm apart. Thin plants to 15-20 cm apart. Make further sowings every three weeks.
Shade is preferable in summer. Protect from slugs and snails.
Buttercrunch is heat-tolerant. Different varieties of lettuce suit different seasons.
They grow best in moisture-retentive soil, rich and well-drained. Wet feet causes rot, and dry feet makes them bitter.