Johnny's HEAD LETTUCE Planting Program

Johnny's Head Lettuce Planting Program is designed to take the guesswork out of your lettuce succession planting and production, allowing you to more easily extend your harvest across your growing seasons.

Full-sized heads of lettuce are an essential product to have on hand, whether at home, at market, for CSA shares, or the farmstand. Variety selection is key in providing your customers with a continuous supply. To develop your production strategy, use the recommended program outlined below as a guide to choosing early season, mid season, and late season head lettuce varieties. We also offer recommendations based on ouro trials for all-season/year-round head lettuce production.

See also our notes on heat tolerance and lettuce downy mildew.

• Plant in cool weather (early spring) for harvesting in warm weather (late spring and early summer).
• Varieties are selected for quick growth so they develop full heads.

• Plant in warm weather (late spring and early summer) for harvesting in hot weather (mid and late summer).
• Varieties are selected for heat tolerance — i.e., resistance to bolting and tip burn.

• Plant in hot weather (late summer), up to 60 days before first frost, for harvesting in cool weather (fall).
• Varieties are selected for disease resistance and cold tolerance.

• Planting in any season, with best chances of success and consistency.
• Varieties are selected for their adaptability under varying conditions.

Heat Tolerance

Even heat-tolerant varieties have upper limits of temperatures they can withstand. At lower latitudes and in geographic pockets of intense summer heat such as the South and Southwest, growers may suspend field planting of lettuce during the warmest part of the season.

Lettuce Downy Mildew

Cultivated lettuce is the main host of this pathogenic water mould (Bremia lactucae). With its multiple, ever-evolving races, it is most common where lettuce is grown intensively year-round and spreads readily during cool, damp weather. The spores are wind-dispersed and infect outer leaves first, but can spread rapidly in the field and post-harvest. For best success:

• Choose varieties with the highest, most comprehensive list of isolate resistances across the following ranges: EU 16–36 and US 5–9.
• Focus prevention and control measures on your riskiest planting slots (fall, early winter) and locations (tunnels, beneath row cover).
• Trial new varieties to determine best performance, as isolate pressure varies by region.

» Downloadable, printable PDF of Johnny's Head Lettuce Planting Program