Plant · P-279

Lettuce

Lactuca sativa

Lettuce grows fastest and best in the cool season, sown so it sizes up before the first freeze rather than racing a heating spring. A bitter, bolted plant is not a failure - it is the same lactucarium-rich sap prized as a mild sedative, so a few plants can be let bolt on purpose once the leaf harvest is done. Heading and romaine types need the long cool run of an autumn planting; only fast, cut-and-come-again leaf lettuce is worth sowing in spring, since summer heat outruns a head before it forms. Afternoon shade from a taller neighbour is the cheapest trick for stretching the harvest window at either end of the season.