Sue R. writes: I have a new raised bed built with redwood and all set with timed irrigation. I planted a variety of lettuce starts and, to my dismay, the very next day, when I went out to check, they were almost eaten to the ground. Do you have any idea what ate the lettuce? This is a very expensive experiment. Also, do you have some favorite varieties that you can recommend?
It could have been slugs, snails, earwigs or birds. If indeed it was slug or snail damage, you will see slick-appearing trails on the soil surface and on the remaining vegetation. Try baiting with the product Sluggo, which is safe to use around vegetables.
Earwigs do not leave trails but leave a notching appearance on the leaves. Try wrapping moist rolled newspaper around the edges of the box. Earwigs will hide in the moist newspaper rolls and you can discard the captured insects. Also effective for trapping earwigs is a solution of vegetable oil and a little soy sauce placed in a low container. The insects are attracted and will drown.
Birds love newly planted lettuce and can readily devastate a new planting. Purchase some lightweight floating row cover and loosely cover the entire bed, anchoring it around the edges with stones or boards.
This is a wonderful product to use as it allows moisture and sunlight to reach the new plants. As the lettuce grows, the material gently lifts without weighing down the plants. Most important, it does a fine job of keeping flying insects and birds from devastating tender new plants.
To really determine what is causing the damage, play an investigative role during the evening with a flashlight. This is when you will find damaging insects, since they are most active after dark. And of course, check during the day for flights of birds enjoying the harvest. Don't give up on your lettuce.
Here are some favorite lettuce varieties: Red Sails, Oakleaf, Silvia Red Romaine, Freckles, mesclun mixes, Salad Bowl and arugula. It is always fun to try different varieties interspersed with colorful Johnny-jump-ups or violas for a colorful and edible bed.