Sunday, October 9, 2011

How about harvesting lettuce for thanksgiving !

Ajay Nair
Department of Horticulture, Iowa State University

Fresh, crisp, and savory butterhead lettuce for thanksgiving ! at least that is what our lab is aiming for. We recently planted a lettuce trial at the Iowa State University Horticulture Research Station to evaluate the feasibility of a lettuce crop planted as late as 3rd October. Lettuce transplants were grown in the greenhouse for 3 weeks and later hardened off outside for a week. The objective of the study is to evaluate  season extension strategies through the use of row covers and high tunnels. Lettuce transplants were planted outside and in high tunnel on 3rd October 2011.  We planted two rows of lettuce on raised beds with plastic; 10 inch spacing between rows and 8 inch spacing between plants within a row.  Row cover will be installed during the second week of October. 

Transplanting in high tunnel
Field planting of lettuce

Lettuce is an excellent cool season crop that can be grown in 70 days from seed to harvest. Transplant production takes around 20-25 days (including hardening period) followed by 40 to 45 day growth leading to harvest. Lettuce is adapted to cool growing conditions with the optimum temperatures for growth of 60 to 650F. Sensors have been installed both above and below ground to record soil and air temperature. Results from the experiment will provide data on microclimate modification resulting from the use of row covers. Hopefully our results will provide growers with useful information on season extension strategies and a green thanksgiving meal !