We love lettuce fresh from the garden. In fact we love lettuce so much that we do everything we can to have lettuce growing in the garden all year long. Lettuce is, for the most part, a cool weather plant. Most varieties of lettuce prefer to grow in temperatures not much more than 75 degrees. We have found that fall is really the best time of the year to grow lettuce. In spring you are rushing to get all your lettuce harvested before the heat sets in and turns the leaves bitter. But in the fall temperatures are cooling making it the perfect time for lettuce growing. And most years we can get lettuce to stay tasty until the middle of December with some protection.
So there are 4 important things to remember when growing lettuce in the fall. Timing of planting, the varieties of seeds you plant, protection from the heat of late summer and protection from the cold of early winter. Let’s talk about each of these.
If you are planning on growing lettuce in the fall the most important thing to keep in mind is the timing of when you plant those seeds. You should aim to start getting seeds in the ground about 60 days before your first frost date. For example our first frost usually arrives right around October 1st, so we start planting lettuce either in the garden or indoors in our seed starter on August 1st. If your first frost date is November 1st then you could wait til September 1st to plant. The key is 60 days.
Now can you get away with 45 days? Of course, but 30 days before your first frost will be pushing it. You need to have some well established plants by that frost date. Also keep in mind that anything planted in the fall will take longer to mature than it would in the spring. If your seed package says your lettuce will be ready to eat in 45 days then plan on 55 to 60 days in the fall. Your daily amount of sun will be decreasing in the fall so it just takes longer for the lettuce to be ready.
Variety selection is the least important part of growing lettuce in the fall. Really not a ton to tell you here. Most lettuce that you grow in the spring will also do well in the fall. But I would avoid “head” lettuce and stick with either leaf lettuces or lettuces that form smaller looser heads. Butter Crunch lettuces do very well in the fall as they don’t form a heavy solid head. Some smaller varieties of romaine lettuces also do well, we grow a variety called Paris Island that usually gets a nice head developed by late November. Varieties that we have enjoyed and have grown well in the fall include black seeded Simpson, Butter crunch, Paris island cos, oak leaf, Nevada and most types of red leaf lettuces.
Protection from the heat in Late Summer
If your summers are anything like ours then 60 days before your first frost is probably still pretty hot! In August we have at least 10 days over 100 degrees. That can be rough on new lettuce plants. So you do need to baby those seeds and seedlings a bit when growing lettuce in the fall. First off be sure to keep your lettuce beds moist, not soggy wet but moist so that the newly planted seeds can germinate. Until seeds have sprouted and are a week or so old I may lightly water my lettuce beds twice a day. Once they are established they will do better but still be sure they get plenty to drink.
A simple frame hoop with some shade cloth on it can also really help your lettuce plants when it is still super hot. This isn’t strictly necessary but it sure can help.
Another method we use to defeat the late summer heat is to start our lettuce indoors in our seed starter. If you do this, it’s easier to control the environment that your lettuce grows up in. I use some simple cell packs and thin to one plant per cell. I keep them indoors for 4 to 6 weeks, fertilize them once a week with a good organic fertilizer and they will be ready to go out just a few weeks before your first frost. This method also had the added benefit of producing a very pretty finished product. It’s easy to plant a nice neat bed of individual plants that will look fantastic all fall!
Protection from early winter cold
Lettuce is hardy, but it’s not super hardy. It can handle a few nights of frost but will quickly turn to mush if it sits out unprotected for too many evenings with temperatures below freezing. Simple protection is all it takes to get your crop to last well into the late fall and early winter.
Try buying some fabric row cover. This simple and inexpensive garden tool can really save your lettuce from a cold night. The heavier row cover fabrics can protect your crops for up to 6 to 8 degrees. This means your lettuce will be snug and warm on nights as low as 26.
For even more protection try a hoop house or even better a cold frame. Either of these simple structures will keep you growing lettuce in the fall well into the days when you have temperatures as low at 20 degrees! You can learn more about Hoop houses and cold frames by following these links. The links will hook you up with some posts I wrote on using both. You can also go here to see a great post on how to build a really nice cold frame.
All great things must come to an end and the lettuce harvest usually comes to an end when night time temperatures reach that 20 degree mark (even in a cold frame). So if it looks like your night time temperatures are going to drop below that mark and stay there for a few days then it’s time to harvest the rest of your lettuce and bring it in and put in the fridge. Most lettuces will stay good in the fridge for at least another two weeks giving you tons of crunchy salads well into December.