Garlic is one of those crops sometimes not considered since it harvests in the middle of the summer, then leaving an area fallow or to attract weeds until fall tilling or winter cover crops are planted. One way to get around that is to plant a fall crop that will still bear before the hard frosts come. At the same time as planting seeds - Memorial Day Weekend around here - we plant butternut squash seeds in a medium size pot. After growing for about a month they typically have a couple of pairs of leaves when planted. When they are planted at the beginning of July, the garlic has not been harvested so the plants go in the walkways, one on each end and one in the middle (the plants are about 20' apart). It is actually a group of 2-4 plants in each spot. This is what is looks like a month later - all the garlic is harvested from the area:
By fall, the plants will cover the area and produce many butternuts that will be sold wholesale.
It also is certainly possible to plant short season crops such as lettuce or greens except they are hard to establish as the weather gets drier and hotter and will go to seed quicker. A fall crop such as pumpkin or squash is much less work as the days get busier with tomato, bean and corn harvest. As the days transition to less time outside because more time is needed inside to process, it's nice to have these vines covering the area and keeping out the weeds - and providing wonderful food for the winter!