Planting a fall vegetable garden is a matter of timing.
Most fall vegetable garden crops are cool-weather vegetables; they include many of the same crops you plant in the spring vegetable garden.
The time to plant vegetables for fall and winter harvest is mostly determined by temperature, specifically when you expect the first frost or freeze to visit your garden.
Simply, if you know the average date of the first frost in your area (a local nursery can tell you this); you can simply count backwards from that date the number of days each crop you plant requires to mature to determine that crop’s planting date. For example, if the first frost in my garden is expected on November 1 and I want to plant leaf lettuce that requires 45 days to mature, then counting backwards my planting date would be about September 15.
Some cool-weather crops can tolerate frost but not a freeze. Some cool-weather crops can tolerate freezing temperatures if protected with thick mulch or plant blankets.
Long-staying and short-staying vegetable crops
When planting the fall vegetable garden, group planted crops by the number of days they require to harvest and the amount of protection each requires. For example, I would want to plant lettuce and spinach close together because they come to harvest in about the same number of days and I can protect both crops from an early frost or freeze by placing a plant blanket over both.
Fall vegetable crops can be categorized as long-staying and short-staying crops. Many long-staying crops can tolerate frost and can stay in the garden past the first frost date, short-staying crops can’t.
Plant long-staying, frost-tolerant vegetables together. Frost-tolerant vegetables include beets, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, chard, collards, garlic, kale, lettuce, mustard, onions, parsley, spinach, and turnips.
Plant short-staying, frost-susceptible vegetables together. These crops will be removed from the garden after the first killing frost. Frost-susceptible vegetables include beans, cantaloupes, corn, cucumbers, eggplants, okra, peas, peppers, Irish potatoes, sweet potatoes, squash, tomatoes, and watermelons. (Many of these crops are warm-season crops, but if you choose a variety with a short number of days to maturity, you can include these in your fall garden.)
To plant the fall garden keep the following things in mind: (1) the number of days to maturity and harvest; (2) the average height and width of the plant, the amount of space it will require; (3) the frost sensitivity of the crop—is it frost-susceptible (FS) meaning it will be killed or injured by temperatures below 32°F degrees or is it frost-tolerant (FT) meaning it can withstand temperatures below 32°F.
Crop guide for the fall vegetable garden:
The short-staying or quick maturing (30-60 days) vegetables are: beets (½ foot) FT; bush beans (1½ feet) FS; leaf lettuce (½ foot) FT; mustard (1½ feet) FT; radishes (½ feet) FT; spinach (½ foot) FT; summer squash (3 feet) FS; turnips (½ foot) FT; and turnip greens (½ foot) FT.
The moderate (60-80 days) maturing vegetables are: broccoli (3 feet) FT; Chinese cabbage (1½ feet) FT; carrots (½ foot) FT; cucumbers (3 foot) FS; corn (6 feet) FS; green onions (½ feet) FT; kohlrabi (½ feet) FT; lima bush beans (1½ feet) FS; okra (6 feet) FS; parsley (1 foot) FT; peppers (3 feet) FS; and cherry tomatoes (4 feet) FS.
The slow maturing or long-staying (80 days or more) vegetables are: Brussels sprouts (2 feet) FT; bulb onions (1 foot) FT; cabbage (1½ feet) FT; cantaloupes (1 foot) FS; cauliflower (3 feet) FT; eggplant (3 feet) FS; garlic (1 foot) FT; Irish potatoes (2 feet) FS; pumpkins (2 feet) FS; sweet potatoes (2 feet) FS; tomatoes (4 feet) FS; watermelon (1 foot) FS; and winter squash (1 foot) FS.