Begin first planting 3/28 and seed every two weeks throughout the season. Start in 78 cell trays.
Seeds are small so be careful not to double seed (it is easy to plant way more than planned). If no 78s are available, plant a 2 or 3 seeds per cell larger trays. Seedlings grown in this way are pretty easy to separate during transplanting if careful.
Lettuce does not need to be transplanted in the greenhouse.
Move seedlings outside when plants are 1 to 3 inches tall. Space the seedlings every foot with 4 rows per bed. Use row cover for the earliest plantings. Lettuce can tolerate frost and even light snow, but row cover will speed the growth.
Be watchful from late June onwards for signs of bolting. Signs include growth up instead of out, heads becoming firmer on top, and the formation of a cone. If any of these signs are noticed, harvest all the plants that are close to bolting as they can bolt in just a day. Be sure to water sufficiently during the heat of the summer, even with heat and bolt resistant varieties.
Keep lettuce well cultivated when it is young. As the plants mature, they will block out weeds, but they need help until then.
There have been problems with slugs and snails chewing the lettuce in past seasons. There are more when the weeds are not under control, so weed management is crucial. Also try putting a can of beer in the lettuce. Slugs and snails are attracted to beer and will crawl into the can and drown. This has only had mild success. Another option is putting out a board in the lettuce and killing all the slugs under it in the mornings in salt-water bath. The only guaranteed way to control these pests is to pick them off by hand.
It is important to harvest lettuce early in the morning and get it into cool water quickly to minimize wilting. Using the large blue-handled harvest knives, gently bend the head or lettuce away form the ground and cut the stem at or just below the soil line. Harvest into a yellow lug, packing only one layer deep. Be very gentle if packing two layers in a green lug. Immediately after harvesting, wash well in cool water. In the tub, pull off any outside leaves which have even a bit of discoloration which is caused by rot and will cause the head to spoil more quickly if not removed. (These leaves may still be mostly fine, and can be saved for a farmer’s lunch). When discolored leaves are removed, and the head is dirt and slug free, hold the it underwater and cut off a thin slice from the base of the stem, then rub the stem end with your thumb. This helps seal and heal the cut, and the head will keep longer.
Harvested early in the morning, and washed and stored in a perforated bag in a yellow crate lettuce will keep well in the refrigerator for several days. The best packing method is a single layer with heads aligned all up or all down. Amish Deer tongue does not keep as well and the leaves tend to rip easily.
For retail, sell small heads for $1.50 and standard heads for $2.00. For wholesale, sell for $1.00 a head.
Lettuce can be planted with carrots and radishes.
Be sure to stay on top of planting even during busy times. Otherwise there will be a gap when no lettuce available.