There is so much you can plant in the mid to late summer for an abundance of produce in the fall.
Carrots and beets can be started as early as the first week of July. Try to plant by the first week of August. Be aware that because carrot seed is small, planted shallow, and takes up to 2 weeks to germinate, you will need to keep the seed moist with daily watering, or twice daily if your soil is sandy. Placing floating row cover over newly seeded carrots helps to conserve moisture.
Radishes and Turnips grow quickly and can be successfully established from a September 1st planting.
Rutabagas are a delicious root crop that can be planted in August for a supply of cold hardy roots over the winter and into spring.
Sweet Onions can be seeded in late August to be transplanted out around early October for a May/June harvest the following year.
Cabbage, kale, collards, lettuces, chard, spinach should be started by mid-July for transplanting out in mid-August transplanting or you can direct seed them at the end of July.
Basil started in late summer basil can be protected in a greenhouse, cloche, or with row covers as the weather cools.
Parsley, dill, and cilantro can be planted in late July to early August for fall pickling and fresh eating.
Snap peas and snow peas love the cool weather and you can grow beautiful fall crops by planting the first week of August in a part of the garden that gets afternoon shade.