25 Things to Plant in September for a Fall Garden

The difference between a fall garden that feeds you and one that just composts itself comes down to timing, and the window is tighter than it feels.

Wait until the air actually turns crisp and a lot of these crops won’t have time to establish roots before a hard freeze shuts everything down. T

he trick nobody tells you: you don’t plant fall crops forward from today, you plant backward from your first frost date.

Take the days-to-maturity on the seed packet, add about 10 to 14 days for the shorter days and cooling soil to slow everything down, and count back from your own frost date. Grab your zip code’s date from the Old Farmer’s Almanac and get moving.

Here are 25 things to get in the ground in September, roughly grouped by frost tolerance, from the crops that shrug off a hard freeze to the ones that only take a light frost, plus a few special cases at the end.

1. Kale

Kale doesn’t just survive frost, it wants one.

Cold weather flips a switch that converts starches to sugar, and a kale leaf that got hit by a hard freeze tastes noticeably sweeter than one picked in August. It’ll hold up to around 20°F, so this is one of the last things you need to worry about.

2. Collards

Collards run with kale in the toughest tier of the garden.

Some varieties, like ‘Blue Max’, shrug off temperatures down to 0°F, which makes them one of the few crops you can basically ignore once they’re established.

3. Brussels sprouts

Brussels sprouts need a long runway to mature, so putting them in during September only works from established transplants in mild-winter zones with a late first frost.

Like kale, a freeze sweetens them, which is the closest thing to a garden cheat code you’re going to get.

4. Cabbage

Cabbage sits in the same hard-freeze club, tolerating temperatures down to around 20°F once it’s established.

In mild-winter regions with a late frost date you can still set out transplants in September and keep heads growing well after your tomatoes are a memory, but farther north that ship has usually sailed, so check your frost date first.

5. Broccoli

Broccoli wants roughly 65 days to head up, plus about two extra weeks for the fall slowdown.

In zone 7, where the average first frost lands around October 25, that math puts the transplant deadline back around August 7. So September planting really only works in warmer regions with a much later frost date, and even then from established transplants, not seed.

6. Carrots

Carrots are root cellar royalty for a reason.

The tops are only half-hardy, but the roots ride out hard freezes when you cover them with a thick layer of insulating mulch, and like kale, the cold converts starch to sugar underground, so a carrot pulled after a frost tastes noticeably better than one pulled before it.

Sowing them this late leaves enough time only in long-season, mild-winter areas, so elsewhere treat a September planting as an overwintering gamble.

7. Parsnips

Parsnips take the sweetening trick even further, staying tolerant down to around 0°F in the ground.

They’re slow to mature, though, so a September sowing only pays off where winters stay mild, or where you’re happy to leave them under mulch and dig them as needed through the cold, since the flavor keeps improving the longer they sit.

8. Rutabaga

Rutabagas are basically a bigger, tougher turnip, and the roots take a hard freeze in stride once you’ve mulched over them.

They need most of a season to size up, though, so September planting is really a mild-zone move, and where it works they’ll be one of the last things standing in November.

9. Leeks

Leeks are deceptively hardy. Certain varieties, like ‘Bleu de Solaise’, tolerate temperatures all the way down to 0°F, which is wild for a plant that looks like an oversized green onion.

They take a long time to size up, so a September planting is about overwintering those hardy varieties in mild zones rather than a quick harvest.

10. Turnips

Turnips are a tale of two vegetables. Standard turnips take a light frost easily and the roots hold through colder weather with some mulch over them, though they’re less cold-hardy than the true hard-freeze crops and want protection to keep growing deep into winter.

Hakurei turnips, the sweet salad type everyone loves, don’t survive below about 10°F, so know which one you planted before you assume it’ll ride out a cold snap.

11. Beets

Beets sit in the lighter-frost tier, holding up through the low 30s but not a real hard freeze. Get them in early enough and you’ll be pulling beets well into fall.

12. Cauliflower

Cauliflower is fussier than its brassica cousins and only tolerates a light frost, not a hard freeze. Treat it like you’re racing the calendar instead of counting on cold tolerance to bail you out.

13. Green onions

Green onions are forgiving about timing and only need to shrug off a light frost to keep producing. Good pick if you’re getting a late start and want something that won’t punish you for it.

14. Leaf lettuce

Leaf and Bibb lettuces handle a light frost but check out once temperatures drop into a real freeze. A cold frame or row cover buys them a few extra weeks if you want to push it.

15. Mustard greens

Mustard greens split the difference. They’ll take a light frost, they grow fast, and they’re one of the better options if you’re planting on the later end of the September window.

16. Radishes

Radishes are the closest thing to instant gratification in a fall garden. They mature so fast you can sow them as late as mid-September in a lot of zones and still get a harvest before things shut down.

17. Spinach

Spinach tolerates a light frost and actually prefers the cooler temperatures of a fall planting to the heat stress it deals with in spring. It’s one of the better arguments for treating fall as a real second season instead of a wind-down.

18. Swiss chard

Swiss chard takes a light frost in stride and, like a lot of this list, gets a little sweeter once the temperature drops. Easy pick if you already have a summer bed you’re not ready to give up.

19. Arugula

Arugula grows fast and handles a light frost, which makes it a solid choice if you’re squeezing a September planting in around everything else on this list.

20. Bok choy

Bok choy and other Asian greens are quick growers that do well in the cooler, shorter days of a fall garden. Get them in now and you’ll be harvesting before most of your neighbors’ gardens have gone dormant.

21. Kohlrabi

Kohlrabi doesn’t get enough credit. It matures fast, handles cool fall weather well, and tastes like a cross between a turnip and a mild cabbage that more people should be growing.

22. Cilantro

Cilantro is the one on this list that’ll surprise you. Everyone treats it as a spring herb, but it makes a great fall crop. It shrugs off a light frost and, in warm-summer climates, does far better in September’s dropping heat and daylight than it ever does bolting in the spring.

23. Snap and snow peas

Peas are the fall crop most gardeners forget exists. Sow quick-maturing varieties like ‘Alaska’ or ‘Little Marvel’ from late August through mid-September while the soil’s still warm enough for the seeds to germinate, then let them mature into the cooler weather. Once established, they handle a frost fine.

24. Garlic

Garlic is the one item on this list where, in most regions, September is prep month, not planting month. You’re usually ordering seed garlic and prepping soil now, with cloves going into the ground in October, sometimes as late as a week or two after your first killing frost. In cooler-climate areas with an earlier frost, though, like parts of Oregon and high-altitude western Colorado, September can fall right inside the recommended planting window.

Extension offices don’t even agree with each other on the exact window, so check your local timing instead of trusting a single date. What’s not in dispute is why fall planting matters at all. Garlic needs a stretch of cold to trigger the bulb to divide into cloves next spring, so skipping the cold isn’t optional.

25. Cover crops

The most valuable thing on this list isn’t food at all. Winter rye and clover planted now protect bare soil from winter compaction and erosion, suppress weeds, and add organic matter back into your beds.

Clover fixes nitrogen and pulls buried nutrients toward the surface. Rye germinates fast, digs deep roots that break up compacted soil, and forms a weed barrier that’ll save you a headache in spring. Pair the two since rye doesn’t fix nitrogen on its own. Legumes want about 6 to 8 weeks before your killing frost, rye more like 4 to 6.

The Bottom Line

Half of gardening in September is admitting the season isn’t ending, it’s changing shape. The plants on this list don’t care that it doesn’t feel like fall yet. They care about your frost date, and that clock started weeks ago whether you noticed or not.