Vegetables can still be productive for a couple more months, depending on what crops you have been growing. Certainly long season crops like tomatoes, peppers, and Swiss chard are there now and will continue to produce until frost for the tender vegetables and longer for Chard, which will tolerate quite a bit of cool or cold weather. If you planted your cabbage transplants in late June into early July then fall crop will be ready anywhere from September through November, depending on variety. Root crops like turnips, carrots, beets, parsnips, potatoes and onions can be harvested anytime they are ready and into frosty weather. If you mulch the rows with straw and prevent freezing, root crops can be harvested even with snow cover.
Gardeners can use late season extenders to allow those more tender vegetables to last a little longer. These can be as simple as protecting from the earliest of frosts by covering tender plants with an old bed sheet or light blanket. More involved will be a temporary structure created over the rows or setting the cold frame you used in the spring over a portion of a row or rows. Most anything you used in the spring to protect your vegetables from the late frosts can be reused to protect from the early fall frosts. It seems a bit odd to add this last part in a column in August. As fall comes on, if you have valuable produce close to being mature enough to harvest, be prepared to harvest if you cannot protect the plants from cold weather.
A trend in vegetables the past couple of seasons has been the idea of growing greens and harvesting them while they are very small and tender. Our season may not allow us to grow lettuces, greens and spinach to their mature sizes, yet we can certainly harvest them as whole, smaller plants for fresh table use in salads and garnish for other dishes as well.
What you do not want to keep growing are the weeds. Especially do not allow them to go to seed, even I the areas where you already harvested all your vegetables and may not be spending much time in now. This will set you up for a weed problem next year. Since most gardeners do not have a “hot” composting system, those weed seed heads should NOT be added to the compost bin. We have all had tomato plants show up in beds where we used our own compost as organic matter, for example. If you have enough of an open area, consider sowing a cover crop to help condition the soil and keep the weed population down. You can turn them in late this fall or leave them as winter cover if you like. If you routinely turn in all your plant parts each year, do no turn in diseased plants that will provide disease inoculum for next year. Gardeners who mow, mulch and bag their tree leaves also have the option of using those in the garden as well, turning them in alone or with other kinds or organic matter.