You can reduce transplant shock by avoiding too rapid growth during plant production and by hardening the plants. Expose the plants to outside conditions during the last 7 to 10 days before transplanting. The beds should be thoroughly watered the day before transplants are pulled so that minimum root damage will occur. Consult Horticulture Information Leaflet 8104, Growing Vegetable Transplants for the Home Garden. Late cultivation, especially when soil is moved toward the plant, may result in excessive soil in the lower part of the head.
Herbicides are available for weed control in lettuce.
Lettuce is attacked by aphids, armyworms, imported cabbage worm, and loopers. The pest pressure on summer and fall crops is much greater than on spring crops. Damping-off is a serious disease of young seedlings, whereas mildews and sclerotinia are serious on the more mature plants. Both insects and diseases can be controlled if the correct chemicals are properly applied. Consult your Cooperative Extension agent regarding pest buildup, proper diagnosis, and control.