Lettuce
Lettuce is susceptible to freeze damage, but is fairly cold tolerant, making it a great option for growing in a season extender such as a low tunnel or hoop house. There are many types of lettuce. Leafy varieties mature quickly and typically tolerate the heat better. Romaine has upright leaves with a strong mid-rib. Butterhead has a rounded shape and requires more time to mature. Head lettuce takes almost twice the amount of time to reach maturity compared to leafy lettuce. It is a better option for fall gardening.
Lettuce can be direct seeded or transplanted in mid-March through early April. That means, if you plan to grow transplants, now is a good time to get seeds started. Lettuce will germinate best with light and warmth. Soil that is too cold will slow germination. On the contrary, soil over 85 degrees F will prevent germination altogether. When seedlings have four to six true leaves they can be transplanted into the garden.
Peas
Peas can be direct seeded into the garden in early to mid-March as long as the soil is dry enough to work. If planting is delayed peas may not reach maturity before the heat arrives and stops production.
Consider early maturing varieties with resistance to powdery mildew. Some varieties have vines that will grow up to five feet tall and require trellising. Dwarf varieties do not require staking.