The growers’ objectives were to document the best iceberg lettuce varieties for successional head production across different farms in southern Ontario; and to assess the viability of the varieties for seed production in Zone 3 in northern Ontario.

In a Nutshell

• Iceberg can be a difficult lettuce to grow and market because of the variability and inconsistencies in head development
• Due to issues with replication, no concrete recommendations can be made on which iceberg variety is best for successional head production in southern Ontario
• Two varieties that rose to the top for growers were Laibacher Eis 4 and Marius, both of which came from a co-operative organic breeding network in Germany
• Due to disease pressure, no seed was produced in Zone 3 from any of the iceberg varieties