Many plants grow slower in fall due to shorter days and less intense light, but these crops don't seem to care. I also plant my cold frame full of greens. The cold frame will protect the greens from light frosts and extend the harvest time into November and sometimes December depending on the fall. If you thought ahead you might have started some cole crops such as cabbage of broccoli indoors in July for transplanting outdoors now. If not, check local garden centers.
Place transplants on raised beds, protected from pests with a floating row cover.
Transplants have many more insects to contend with in late summer than spring. Fertilize lightly with a manure tea or fish emulsion. Leave some of your parsnips, carrots and beets in the garden and before a hard freeze cover them with a thick layer of straw as winter protection. You'll be able to harvest roots for the holidays. Garlic and Shallots Fall is the best time to plant garlic and shallots.