If planting directly in the ground, enrich the soil by incorporating ample well-decomposed garden compost beforehand. This aids in deterring lettuces from prematurely bolting or going to seed, particularly in dry or hot conditions, especially with lighter soil types.
Sow the seeds sparingly along a damp trench about 1cm deep, formed by pressing a bamboo cane into the soil. Lightly cover the seeds with soil or vermiculite (they thrive better when exposed to some light). Maintain a distance of 30cm between rows.
Ensure the soil remains adequately moist, particularly in warm weather, to prevent your crop from bolting (going to seed prematurely). Apply mulch around your lettuce plants to retain soil moisture and provide nourishment. Sowing early or late in the season reduces the likelihood of bolting. Keep the area surrounding your plants free from weeds and safeguard young plants against slugs and snails.
Slugs and snails pose a significant threat to crops; combat them by employing copper-infused mats or mulching the soil with coarse grit or crushed seashells. As a final measure, consider using slug pellets made from Ferric phosphate that are friendly to wildlife. Additionally, red or purple lettuce varieties appear to be less susceptible to attacks.
The downy mildew fungus presents a risk of ruining your crop, especially during wet late-summer weather. Prevent this by refraining from splashing water onto the leaves while watering and ensuring ample spacing between lettuce plants to encourage proper air circulation, mitigating the risk of infection.
Begin harvesting baby loose-leaf lettuces around the six-week mark, while hearting types are typically ready for picking at 10 weeks. In warmer conditions, you'll observe varying succulence in your lettuces based on the time of day they're harvested. Optimal harvest time is early morning when the leaves retain their moisture, avoiding dehydration from the sun.