I know you've just started to miss peas and your lettuce is bolting, the good news is that fall planting is coming up soon! I have added the fall planting schedule to our planting schedule on the left column of our home page. This schedule is based on a 1st frost date of October 10th and the dates are chosen in order for the harvest to be done about that time. This may require some protection from July and August heat on some varieties that are marked with an *. A great way to protect them is to grow them in the shade of taller plants. You can also choose to wait and plant later, you will just shorten your harvest, unless we have a later frost.
If you plant cold hardy varieties of lettuce and spinach, you can lengthen your growing and harvesting time into the winter. See chapter 6 of 'The Forgotten Skills of Self-Sufficiency used by the Mormon Pioneers' by Caleb Warnock for cold hardy variety recommendations.