Solving Lettuce Problems
Don't write to the seed company right away. Most often, poor germination is caused by letting the seedbed dry out. It has to be continuously moist. Drying out occurs more often during hot-weather plantings, and not as much with early spring plantings. Sometimes a light mulch of hay or straw to shade the soil after you plant will keep the soil moist until the plants are up. But don't delay in removing the mulch once you see the plants.
Also be sure to cover the seeds correctly - use just 1/4 to 1/2 inch of moist soil. If your soil gets very crusty and hard before the plants are up, gently run a lawn rake over the surface to break up the hard soil.
Bitter lettuce is usually old lettuce, and the older it is, the worse it tastes. Harvest lettuce when it's young - as soon as there's something to eat - and harvest often. Don't wait for leaves to get big. Make frequent plantings of different varieties through the summer, so you'll always have tender sweet lettuce coming in.
Seedstalks develop with warm weather and long days. It's the natural urge of a plant, and there's nothing you can do after lettuce bolts. Bolting won't affect you if you make successive plantings and harvest early. Cut the entire plant off about an inch above the ground. Also, try slow-bolting varieties such as Black-Seeded Simpson that can take some heat.
Wide-row planting slows bolting, too, as the close-growing plants keep the soil and roots cool.