Lettuce

Lettuce is tasty cool weather crop that is usually grown in the spring and in the fall. It best known for being the main ingredient in many salads, or a topping on a sandwich, and in soups, but some varieties are excellent grilled. Some of the distinct types of lettuce are Cos or romaine, butterhead, leaf lettuce, iceberg also called crisphead, and stem, or asparagus lettuce). The different tastes and textures of freshly picked lettuce from the vegetable garden is second to none. If you've never grown lettuce before in the garden, give it a try... you wont regret it!

 Start lettuce seeds indoors 4 - 6 weeks before last frost or direct sow as soon as the ground can be worked. Sow at a depth of 1/4-1/2" (6-13cm). It takes 1 - 2 weeks to germinate.  Always harden off before transplanting outdoors. Make sure you prepare the soil of your vegetable garden with a good amount of compost and well rotted manure. Lettuce prefers full sun and light to moderate watering. Spacing varies depending on variety. We use shade cloth to help slow lettuce from bolting, when temperatures exceed 70 degrees F (21C). Staggering the seedings in succession plantings every two weeks, and adding more heat tolerant varieties as you go, ensures a steady supply of crisp lettuce later into the season. Enjoy it even later by sowing some lettuce in a mini greenhouse in the fall, or in containers and bring them inside when there could be a threat of frost.

For more on growing lettuce in the vegetable garden see this video on How to Grow Lettuce.

The University of Maryland Extension offers some more information on growing lettuce in the vegetable garden or check out this pdf from Oregon State University Extension

Lettuce is a perfect candidate for succession planting, by spacing your planting out every couple of weeks you can enjoy a continuous harvest, without being overwhelmed with too much lettuce all at once. We like to intercrop our lettuce by filling in any voids around the other vegetables in our spring garden, this can also protect the lettuces by providing some shade on any unusually hot days.

 Lettuce is a cool weather crop that tends to bolt in the heat, which means it switches from leaf production to flowering, this usually causes a bitter taste making it unpalatable. So it is a good idea to add some heat tolerant varieties when planting your spring lettuces. The colder weather does make for the sweetest lettuce, so growing them in the fall garden is ideal. 

When harvesting lettuce try picking the outer leaves while leaving the inner buds to continue growing, especially with loose leaf lettuce. We find the leaves are typically more tender with the loose leaf varieties, than the crisp heading varieties. You can let the entire plant grow then cut it at the base. Most of the loose leaf varieties of lettuce generally mature faster and can be picked at any time, while the heading varieties can take slightly longer.

Common pests like aphids can affect your lettuce. One method to controlling aphids is to introduce beneficial insects like the green lacewing available from Arbico Organics. Lady beetles are another great beneficial insect, but many feel that purchasing them from commercial vendors is not a good idea, one reason is the fact that they wild caught, which could introduce disease, parasites, and other problems that are not native to your area. Another common pest that plagues lettuce is caterpillars. The best way to protect your lettuce from caterpillars is pick them off and squish, or drop into a pail of soapy water, for us its just free chicken food.