Lettuce is a hardy fall vegetable that is best planted in late August for most areas.  If you are in a cold area, plant mid-August, or if you are in a mild climate early September. 

Preparing the soil is key for fall lettuce.  

Remove any plants or plant debris left over from summer. Amend the soil with compost by laying it on top. Usually an inch will work just fine. Slightly work in with a digging fork or even a hand trowel work well. Sprinkle a powdered fertilizer (we use Bio-Fish or Cottonseed Meal) over the compost and rake in and smooth out the soil. Use a bamboo stick or handle of a hoe to make a small indent in the soil about 1/2" deep. You can make several rows next to each other about 4 to 8" apart. For fall planting we like to make our rows closer than usual so plants can support each other in our strong winds and also to allow for a few winter casualties. Sow seeds rather thickly, spacing them 1/4" to 1" apart. Yes we sow our lettuce seeds thick! Lightly bring soil over the top of seeds covering no more than 1/4". If to much soil is cover the seeds, chances are you won't get much to sprout through the soil. Lettuce needs some light to germinate. Cover newly planted seeds with floating row cover. You can water right through the cover. This helps keep them moist, helps the shallowly planted seeds to not move around when watering and keeps birds from robbing the seed. Keep the soil moist, but not soggy.  

Slugs and snails can wreck havoc on new lettuce seedlings. They will eat new seedlings before you even know they germinated. To help combat this we sprinkle Sluggo Maxx lightly around the planted area 3-4 days after sowing seeds.  

Some of our favorite fall planted lettuces:

Little Gem Romain

Magenta 

Freckles

Winter Density Romaine

Rouge d'Hiver