Easily grown in fertile, well-composted, medium moisture, well-drained soils in full sun to part shade. Best red leaf color occurs in full sun. Leaves appreciate some light shade in the heat of the summer. Plants perform best with consistent watering throughout the growing season. Lettuce grows best in cool weather. Start seed indoors about 6-8 weeks prior to last spring frost date. Seed may also be planted directly in the ground about 2 weeks prior to the last spring frost date. Additional seed may also be planted in the ground from last spring frost date to mid June at two week intervals for purposes of extending the harvest season. Plant seed in late summer for a fall crop. Dry soils often trigger bolting.
'Merlot' is a cool season annual that is grown both for culinary use as a red loose leaf lettuce and for ornamental use as a red foliage plant. It typically grows to 6-8" tall. Frilled, dark red leaves in loose rosettes reportedly resemble the color of merlot wine, hence the cultivar name. Baby leaves are ready in 30 days and full size leaves are ready in 60 days. Hot summer weather often triggers bolting (small dandelion-like flowers appear and leaves become bitter tasting).
No serious insect or disease problems. Potential disease problems include downy mildew, powdery mildew, shot hole, bottom rot, septoria leaf spot, Botrytis and wilt. Potential insect pests include aphids, snails, slugs, leafminers and whiteflies. Mosiac virus may appear.
Eating lettuce for salads. Also ornamentally effective in beds and borders or as an edger. May be grown in containers with other cool weather annuals such as petunias and pansies.