It's also a great time to start seasonal plants that will thrive in the cool fall air, including leafy greens like lettuce, spinach, and kale. Because of their fast growth and wide harvesting window, leafy greens like kale, lettuce, and spinach are some of the best options. They are durable and can thrive whether you live in a hot climate, a cool one, or anywhere in between. Thankfully, you don't have to throw together a bunch of beds to get a space ready for these leafy greens. Grow them next to each other, making sure they have enough space to thrive, and you can keep all your greens in one place for a quick harvest at mealtime.