What to Plant in September (What I Learned the Hard Way).

In September, I don't ask what can grow in fall anymore, because plenty of cool season crops are happy as the temperatures drop. What I ask now is whether they have enough time to actually give me food before growth slows way down, and what I kept overlooking wasn't temperature, it was the sun. So today, I'm going to show you nine things that I'd actually consider planting in September, how to know if they're still worth planting where you live, and how to keep your fall garden as simple as possible. I'm in zone 8a in upstate South Carolina, and you can find your own zone by plugging in your zip code into this map, but your USDA zone doesn't actually tell you when to plant your fall garden. Your zone mostly tells you how cold your winters get, and for fall planting, I care much more about two things, my average first frost date and how quickly I'm losing daylight. My first frost usually falls somewhere between late October and mid-November, and that matters for anything that can't survive a freeze, but a lot of the crops that we're talking about today can handle cold, and that's where the sun becomes so important. As the days get shorter, growth is going to slow way down, and once day length gets down to around 10 hours, a lot of fall crops are going to grow extremely slowly, and this isn't a switch where like everything is going to suddenly stop, but it is a really useful benchmark, and I want most of my fall garden crops close to the size that I want to harvest before I get to that point, and this is the big difference between spring and fall. In the spring, every week is going to bring more daylight and generally much faster growth, but in the fall, every week brings less, and I didn't figure that out from looking at charts and things. I figured it out from planting things that came up looking perfectly healthy and beautiful and then stopped growing, and I blamed the weather when the real problem was that I had run out of daylight, and if you want help running that math for any of the crops that we're talking about today, I made a free September planting guide and workbook to go with this video. It has a place to record your frost date and your 10-hour daylight date, a worksheet that walks you through math for any seed packet, the varieties I've actually grown and trust, and a page where you end up with the three things that you're actually going to plant this month. I'll put the link right here on the screen and below this video. The first garden food on today's list is garlic, because although it's the big exception to the daylight rule that I just gave you, it is planted in the fall. I wanted it on this September list because if you've never grown it, I think it's so worth it, and I want you to have the timing right. With garlic, your first hard frost matters more than your remaining daylight. You want to plant it around four to six weeks before your first hard frost so that it can establish its roots before winter, and then you harvest it seven to nine months after you plant it. Here in upstate South Carolina, for me, planting has averaged around mid-October for the past 13 years of growing it, so I'm not planting mine yet, but depending on where you live, September may be your month. Next up is lettuce, and this is where what you actually want to harvest changes the answer completely. Plant lettuce in September could mean harvesting baby leaves in a few weeks or trying to grow a full head before your daylight runs out. Leaf lettuce is the easiest one in my opinion. Depending on the variety, you can start harvesting young leaves around 25 to 30 days, and then you can cut what you need as the cut and come again method where you cut it an inch or two above the soil line, and then it keeps growing. And that's what I'm planting outside right now. I'm tucking seeds into little open spaces between things like my pepper plants because they're going to give the seedling some shade while it's still hot, and that shade also helps the soil hold moisture while those tiny seeds are trying to germinate. So I'm not planting it all at once though. I'm going to plant it a little bit every week so that we have fresh leaves coming along in stages instead of one huge giant harvest at the same time. Head lettuce is different. That can take 60 days or more, so mine is already growing indoors since it's been so hot out. And then I'm going to transplant it once the heat starts easing, probably in like mid-September. Then in late fall to winter, my goal is to keep the mature plants alive under a greenhouse cover over my raised beds like a living refrigerator so that I can harvest from them through the colder months of winter. I've done this before with leaf lettuce where I planted it thick because I wanted a lot of it, and it stayed alive all winter under that cover, which definitely was a win, but it barely grew. It just sat there at the size that it was when the daylight dropped. So whatever size your lettuce is when the days get short is basically the size that it's going to stay all winter, and that's why I'm trying head lettuce this year. I want it big before I lose the light. So if you want full heads, 60 days plus I add two weeks for slower growth in the fall, variety matters too. And right now it's still pretty hot, so I'm looking for heat tolerant, slow bolting lettuce, and that's the lettuce, the leaf lettuce, that I'm going to be planting in between my summer things that are finishing up. For the plants that I want carrying later into fall and winter, I'm going to choose varieties with better cold tolerance. Numbers three and four are spinach and kale, and they're both incredibly cold hardy. Spinach is one of the trickier ones here in upstate South Carolina because I'm watching the temperature and the sun at the same time. If I plant too early, it's still hot enough that spinach can struggle to even germinate well, and the leaves can get tough pretty quickly. But if I wait too long for perfect spinach weather, I'm losing daylight every day. So I'm looking for that sweet spot around mid to late September depending on what the weather is actually doing. Further north, September might be your last chance instead of the beginning of your window, where in the far south you may be waiting longer for the heat to back off. Spinach takes roughly 35 to 45 days to reach a good salad size with shorter days, and it's also great for succession planting. I can sow a small amount every week or so and then harvest the larger outer leaves, and then the center is going to keep growing. Kale is more forgiving, and I don't really like kale that much, but I've grown plenty of it over the years, and if you like it, it's one of the easiest fall things that you can grow. It handles warmer late summer conditions better than spinach does, and here I'd want mine planted by early to mid-September so that it can build a good size plant. And then farther north, that window may already be closing. So these two are almost a perfect example of the September challenge. With spinach, you might be waiting for the heat to leave while the sunlight is disappearing. And with kale, you have a little bit more flexibility, but you still want to get it established while you have some good growing time left. Number five is radishes, and these are one of my favorite things to recommend in September because they're so easy to grow, and they can give you food in three or four weeks. Here in upstate South Carolina, September is prime radish time for me. August is usually too hot, but as the temperatures start to calm down, I can start planting varieties like cherry bell and french breakfast that are ready in roughly 21 to 30 days. Farther north, September may be your last radish planting instead of your first. One year I planted an entire bed of radishes just because I had the space, and then suddenly I had a huge pile of them ready exactly at the same time. I mostly like radishes fresh in salads, and I'll use like a few at a time. So the ones I left sitting there got oversized, and they were tough, and a lot more bitter and spicy than I wanted. So now I succession plant them, and a good starting point is around 10 to 15 seeds per person every week or two, and you can adjust that depending on how much your family actually eats. But they also barely need any space, so you can tuck them into little openings around the garden instead of dedicating a whole bed to them. If you're feeling overwhelmed and you only want to plant a couple of things this September, I'd start by looking at the things that can pay you back quickly, and radishes and leaf lettuce are the two I would reach for first. Next are brassicas like broccoli, cabbage, and cauliflower, and they can look perfectly healthy in the garden and still never give you the part that you actually planted them for. I've grown brassicas for years, and I used to grow as much broccoli as I could so that I could freeze it for winter, but I've also had seasons where I planted beautiful transplants too late, I watched them grow into big healthy plants, and then I lost daylight before the plant even had time to form heads. You can eat broccoli and cauliflower leaves so that the plant isn't totally wasted, but it is kind of disappointing if you didn't plant it just for the leaves. Think about broccoli in the spring. I can transplant a small plant while it's still chilly outside, and then it has time to grow into a big plant and then form the head before summer heat becomes the problem. Fall is the opposite. Spring broccoli is a race against summer heat, and fall broccoli is a race against the winter slow down. Here in upstate South Carolina, I can still squeeze in broccoli transplants in very early September, but it's kind of a gamble at this point. A faster variety buys you a little bit of time, but even a quicker maturing one still needs weeks of active growth after transplanting before it can start forming crowns. For cabbage and cauliflower, my normal fall planting window has basically closed by September. There is one quicker brassica worth mentioning though, and that's baby bok choy. I've grown this before, and you can harvest it small in around 30 to 40 days along with the slower growth in the fall. So if a full head of cabbage doesn't fit your window, a baby bok choy still might. But this year I'm not growing any of these because I'm just not feeling it, and I've got my mind on something else that I'd rather use that space and energy for. And after enough years of gardening, I've learned that being able to plant something doesn't mean that I have to plant it. And that's the kind of work I do with people one-on-one. We look at your climate, we look at your growing space, what you actually want to eat, and how much time you realistically have for your garden, and what's been getting in the way. And then we get you growing in a garden that fits your life, brings you peace, and actually puts food on your table. So if you'd like to book a free call to learn more about working with me, I'll put the link here on the screen and in the description below. This is actually what I'm focusing on instead of the brassicas this year, and that is root veggies. There's a really nourishing soup that I make with roasted root veggies and my garden garlic and my garden herbs, and I would like to make it every single week. It stretches our meals, and we all love it. I also know what my bandwidth can handle, and I'd rather put my time into the things that we're excited about eating at the moment. Root veggies like carrots, beets, and turnips can be tricky in September too, because they don't all take the same amount of time. A 75-day carrot is a very different choice than a 35-day turnip this late in the season. I've grown carrots every year for about 13 years, and timing is one of the biggest things that I've learned to pay attention to. For my fall carrots, I'm growing Danvers carrots, which take around 75 days, so I've already planted them. I could probably push them into the very beginning of September, but I'd rather have some breathing room. One year I planted my carrots too late, and they came up and the tops looked absolutely beautiful, but the roots stayed small when growth slowed way down. So they made it through the winter, and they started growing again in the spring, but by then the carrots were tougher than I wanted. So if you're just a little bit late on carrots, I would still consider planting them if you're okay with baby carrots, but if you're a long way past your date and you want full-size carrots, I would personally wait until spring. Beets and turnips give you more flexibility because a lot of varieties mature a lot faster than a long-season carrot, so a quick turnip might still fit your remaining window when a 75-day carrot is not going to. Carrots especially get sweeter after cold exposure, and here because my ground doesn't freeze solid, I've left mature carrots in the garden through winter and then pulled them when we needed them. But those carrots are already full-size when winter gets here. If yours are still tiny when the days get really short, they may survive, but they're probably not going to do much growing. Number eight is herbs, and this is another category where saying plant herbs in September is way too broad. I would split them into three groups. First are the hardy perennials like thyme, oregano, sage, and chives. September can be a really good time to plant these here where I live because the worst of the summer heat is starting to ease, but the soil is still warm enough for them to get established before winter. With a new perennial, it's giving it enough time to establish itself so that it's going to come back next year. Farther north, watch how much time you have before the ground freezes. Then you have cool weather annual herbs like cilantro, which prefers the cooler weather that we're heading into. It can handle frosts, and here September is when cilantro starts making sense again after summer heat. I hardly ever plant it anymore because I've let it go to flower and seed in the garden, and new plants come up whenever the weather works. And then there's warm weather herbs like basil, and once the nights start getting cold in the fall, its growth and quality starts to go downhill, and then frost is going to finish it off. If I were to plant a nice size transplant here in September, when it still can be hot, I'd be able to harvest from it for a couple of months still. And number nine is cover crops, which are plants that you grow mainly to protect and improve the soil rather than to harvest. And this one is for the beds that you really don't feel like planting another vegetable right now. For years, I planted cover crop mixes with things like field peas, oats, and hairy vetch, and then I'd mow everything down and turn it into my raised beds. It worked beautifully, but this year I want simple, so I'm looking at buckwheat for some of my empty beds. It grows really fast, it covers the soil, and it's frost tender, so here I have enough September growing time to let it put on some growth before cold weather is going to kill it. If it gets far enough along that it's going to set seed before frost gets to it, then I can just cut it at the soil level and leave everything right there on top of the bed. You just don't want it going to seed unless you want more of it growing back. If your first frost is coming quickly, buckwheat may not have enough time to be useful for you. So there are hardier cover crops that are going to overwinter, but there's also an even easier option. Just mulch your bed. Cover your soil with shredded leaves, a straw, or another mulch, and just leave your bed protected until you're ready to plant again. That's what I do with smaller containers in my garden. I have a lot of big trees in my front yard, so last year I bought this leaf mulching tool, and I shredded and bagged all those leaves for my compost bin and for mulching my garden. And I think that that is a good place to end this list, because I don't want you walking away thinking that you need to plant all nine of these things. You absolutely do not. This is one of the busiest times of year for me. I've got three kids and school starting back up, and honestly I'm tired from gardening through the summer heat, and I know exactly what happens when I try to grow everything just because I technically can. So I am not going to do that. I'm putting more of my energy into the root vegetables that I actually want, keeping things like lettuce, spinach, and radishes simple with small succession plantings, and skipping the brassicas altogether. That's just me. And I don't have to put much energy into herbs, because I have lots of established perennial ones that just do their thing. Like I especially love chives in the fall before they go dormant for the winter. And your list is probably going to look completely different from mine. Maybe this is the first garden that you've planted all year, and fall is finally the season that makes you want to get outside and grow something. Or maybe you've been out here all summer and you're ready to do a whole lot less, and either one is just fine. After growing food for about 20 years, one of the biggest shifts that I've made is realizing that my garden has to fit the life that I'm actually living. I don't want the thing that gives me peace to become another thing that I can't keep up with. I have been in that situation before. So if you're still not sure which of these nine actually fit your window, that's what the free September planting guide and workbook is for. It has the varieties I would look for, a place to find and record your frost date, and your 10-hour daylight date, and a simple worksheet to run that math for your own yard. The link is below the video and right here on the screen. And if lettuce is one of the things that you decide to grow, I have a whole video where I walk you through exactly how I'm planting mine for fall and winter, including the varieties, the timing, and how I plan to keep harvesting it when it gets cold. And you can watch that one right here.