Fall gardening involves planting warm and cool season crops to extend the harvest season. Cool season crops like broccoli, cabbage, carrots and lettuce can be planted in late summer and harvested into fall or overwintered. It is beneficial to plant in fall due to fewer pests and weeds, with crops maturing as days get shorter and cooler. Seeds should be planted 6-12 weeks before the average first frost based on crop maturity times. Seed germination may require pre-sprouting, irrigation and row covers during hot late summer weather.