The 16 Best Vegetables To Plant In September, Based On Gardening Zones

With the first frost quickly approaching in many regions, some gardeners think that fall signals the end of the gardening season. You may be happy to know that it's far from true. What you can plant depends on your USDA hardiness zone — a geographic region defined by a specific climate, and more specifically, by the average annual extreme minimum winter temperature (find which USDA growing zone you're in). However, no matter where you are, you can easily plant a fall vegetable garden in September. It is important to be aware of your climate to ensure your vegetables will be ready to harvest before truly cold weather arrives; that said, some veggies should be harvested after a major frost. 

Some plants, like lettuce, onions, and radishes can be planted in USDA zones 3 to 10 in September. These plants are perfect for gardeners living in most parts of the contiguous United States because they are cold weather crops with fast growing times. However, if you're in a warmer zone, you may want to find varieties that perform better in heat. Other plants, like broccoli, cauliflower, and beets, are suitable for September planting in mild climates with later frost dates because they take somewhat longer to reach maturity. Finally, there are some crops, including most bean varieties, that should only be planted in September in regions that have a much later frost date, such as those in zones 8 to 12.

Arugula (Eruca sativa) is the perfect leafy green plant to start from seed in September in zones 2 through 9, and it's one of the fastest growing greens. It is known for the "spicy" or "peppery" flavor that is relatively bold compared to other leafy greens. You can harvest microgreens in as little as 14 days, and the crops will be fully grown in only six weeks. Arugula seeds can be planted in temperatures as low as 40 degrees Fahrenheit and can tolerate light frost.

Onions (Allium cepa) are a fantastic fall vegetable to plant in September in zones 3 to 12. They need about four to six weeks before the first frost to become established in the ground. In colder zones, full-size onions will go dormant in the winter months and be ready for harvest the following season. In warmer zones where they don't go dormant, you can expect to harvest onion sets in 14 weeks or onions grown from seeds in about six months.

Lettuce (Lactuca sativa) is a vegetable that's perfect for beginners. Plus, it does well when planted in September in zones 3 to 10. You will want to get the seeds in the ground six to eight weeks before the first frost. In colder climates, this may mean closer to the beginning of September. Additionally, choose heat-tolerant varieties in hotter climates like zone 9 or 10. Cold-hardy lettuce likes lower temperatures, and lettuce planted in September will be sweeter than that planted earlier in the season.

Radishes (Raphanus sativus) will grow well in zones 3 through 10 when planted in September, and they can be ready to harvest in just four to six weeks. While you generally don't want to leave radishes in the ground after they reach maturity, if you choose winter radish varieties, you can leave them in the ground for several weeks after they're mature. However, you still want to complete the harvest before the first frost.

Turnips (Brassica rapa) are root vegetables that don't mind a little bit of cold weather, and they grow relatively fast, so they're perfect for September planting in zones 3 through 10. Plant your turnip seeds directly in the ground. In colder regions, you will want to do this earlier in the month to avoid harvesting after a hard freeze; however, waiting to harvest after a light frost will make these root veggies sweeter. The roots will be ready in about six to 10 weeks, but the greens can be harvested at any time while the turnips are still small. 

Not only does garlic (Allium sativum) do well in zones 3 through 10 when planted in September, but it can be planted all the way into October or even November in warmer zones. In fact, you can even wait until after the first frost to put them in the ground — garlic benefits from some time in the cold, needing about 10 weeks in low temperatures to grow properly. Unlike other fall vegetables, however, garlic will not be ready to harvest in the same season. Generally, if you plant it in September, it will be ready for harvest the following July.

Spinach (Spinacia oleracea) is another leafy green that does great in most climates when planted in September. Spinach likes cold weather, so fall is the ideal time to plant it so it can have a full six weeks of cooler temperatures. In colder climates, you will probably want to plant earlier in September; however, it may survive a light frost. Unfortunately, it does not thrive in the hot climates of zones 9 above. 

Moderate climates with later frost dates, like those in zones 5 to 9, are a bit more forgiving with plants that take longer to reach maturity, like broccoli (Brassica oleracea). However, you shouldn't direct sow broccoli seeds in September. Instead, that's when you will want to get your transplants in the ground. You can either start the seeds indoors four to six weeks before you plan to transplant them or look for seedlings at your local nursery. Transplants should go in the ground two to four weeks before the first frost.

Cabbage (Brassica oleracea) is another vegetable that you will want to grow from transplants if you are planting in September. Generally, cabbage can grow in zones 3 to 12, but it performs best in zones 7 to 9 when planted at the end of summer. It prefers warmer climates for late-season planting because it needs 10 to 12 weeks to reach maturity after transplanting but before the first frost. That said, it is hardy against frost and can withstand temperatures as low as 15 degrees Fahrenheit.

Carrots (Daucus carota subsp. sativus) take a bit longer to mature, and they prefer somewhat warmer soil, so they can only be planted in September in zones 7 to 9. They are a bit finicky about soil, but when done right, you can grow carrots of all colors and sizes, even in the fall. You will want to make sure you get your seeds in the ground at least 10 weeks before the first frost. These easy tips that make growing carrots a breeze.

Beets (Beta vulgaris) are another root vegetable that take a bit longer to reach maturity but still give gardeners in zones 7 to 12 enough time to get one last harvest in when planting in September. It could be possible to plant beets in colder regions, depending on the weather conditions. There are two requirements for planting beets in the fall. First, you should make sure your seeds are in the ground at least four to six weeks before the first frost. Second, the ground should be consistently above 50 degrees Fahrenheit for the first five to eight days after planting seeds.

Planting cauliflower (Brassica oleracea) is very similar to broccoli in many ways. Generally, it grows best when temperatures stay consistent at 60 degrees Fahrenheit, so fall is the best time to grow it as long as you get the transplants in the ground six to eight weeks before the first frost. It can be transplanted into the garden September, but it performs best in zones 5 to 9 when planted at the end of summer.

Mustard greens (Brassica juncea) are an interesting vegetable to grow in the fall because you actually want it to mature after the first frost. However, it does take a bit longer to mature, so September is already too late for planting in colder regions. However, in the warmer climates of zones 7 to 10, September is the perfect time. Mustard greens need to be planted through direct sowing between six and nine weeks before the first frost. The goal is to have them reach maturity about two to three weeks after the first frost.

Peas (Pisum sativum) are a common vegetable grown in gardens all throughout the country in spring and summer. But if you're in the warmer regions of zones 7 to 10, you will be happy to learn you can plant them in September, too. You will want the ground temperature to be between 40 and 60 degrees Fahrenheit, but the warmer end of the range is favorable — the seeds germinate a bit slower in colder temperatures. Direct sow seeds in the ground six to eight weeks before the first frost.

Beans are one type of vegetable that can only be planted in the warmest regions in September. Bush beans (Phaseolus vulgaris) need to be planted in soil that is consistently above 55 degrees Fahrenheit during germination. They are not good for transplanting because they have delicate roots, so you will want to direct sow the seeds with enough time (50 to 55 days) for them to mature before temperatures dip below 40 degrees Fahrenheit at night. They will not survive in frost.

Pole beans (Phaseolus vulgaris) are very similar to bush beans as they are both varieties of green beans. When planting in September, pole beans also need to be planted in temperatures above 55 degrees Fahrenheit and have time to reach maturity before temperatures fall below 40 degrees Fahrenheit. However, they take a bit longer to reach maturity — about 55 to 65 days. They also climb much higher, reaching 10 to 15 feet in height if allowed to climb.