Lettuce is the backbone of the spring and fall kitchen garden. Metta is a mix of leaf and loose-head types in greens and reds, so one sowing gives a salad with varied texture and colour, and it can be grown as a cut-and-come-again bed or thinned to heads.
Sow every two weeks from the time the soil can be worked, about a month before last frost, through late summer for a continuous supply. Broadcast thinly and cut the leaves at 4 inches for a baby mix, or thin to 6 to 10 inches for heads. Keep it evenly moist; a dry spell is what turns lettuce bitter and sends it to seed. In summer, sow where there is afternoon shade and expect a gap at peak heat, then resume in late summer for the fall flush, which is often the best of the year.
Lettuce seed will not germinate in hot soil, so for late-summer sowings start it indoors or chill the seed for a few days first. Slugs are the main pest of young plants; a sharp-edged mulch and evening patrols are the usual answers. Light frost improves the flavour of the fall crop.
Downy mildew
Yellowing on top of leaves with grey-purple fuzz underneath. Spreads rapidly in humid conditions.
Remove affected leaves. Improve air circulation. Avoid overhead watering. Copper spray as preventive.