Seeds to sow and what to plant for autumn harvests. Includes information on sowing times, long-day vs short-day veg, and 16 different veg to grow.
We’re in the middle of glut-season. Baskets of tomatoes, trugs of zucchini, and more lettuce than we could possibly eat. It may be far from our minds but within weeks our veg will begin dying down and patches of once productive garden space will be empty. If you plan ahead, it’s possible to keep the homegrown food coming though. The fare will change, and in some cases the growing technique, but with a little forethought you can extend the season into autumn and beyond. It’s not to late to plant for autumn harvests.
There are three important things to understand before you get started. Time to maturity, the difference between short-day and long-day plants, and your own climate. The guide below will help you to choose the right veg to grow and to know when to start it from seed.
Time to maturity for vegetables
The time it takes a seed to fully grow into a crop varies from vegetable to vegetable. It can also vary by variety and time of year. Take lettuce, for example — in the chart below lettuces are given about 40-60 days to grow to maturity. There’s a big difference between those days because it will take longer for them to grow in cooler weather. Sow in late spring and it may only take 40 days but sow in late summer and it may take longer.
Lettuce varieties also play a big role in time to maturity. Smaller varieties, like Little Gems, and leaf lettuce, will take a lot less than head-forming lettuces. There are also varieties better suited for growing in cool weather and through the winter. Lettuce ‘All the Year Round’ is a butterhead that you can harvest up to October when grown outdoors. Other varieties, like Green Oak Leaf and Valdor can be very tolerant of winter temperatures. At least here in Britain.
Vegetables are aware of darkness
Photoperiodism is your word of the day. What it refers to is the number of hours of darkness and light that a plant is exposed to. In growing vegetables, it’s important to us because plants use light, or rather darkness, to tell them time of the year. They use that timing to know when the optimal time to mature and set seed will be.
Leaves are little solar panels and they communicate to the whole plant if the days are drawing longer or shorter. They tally up hours of darkness and strive to set seed at a particular night length. This time varies by plant but long-day vegetables all aim to set seed when days of light rise above a critical threshold. Typically when there’s more than 12 hours of sunlight.
Some veg, like spinach, aims to set seed near the shortest night (longest day) of the year. For us in the northern hemisphere that’s June 21st or round-abouts. That means that even if you keep it well watered and shaded around this time it will still tend to ‘bolt’. The same goes for turnips, rocket, and most other veg.
The trick in growing these long-day plants, is to plan for their maturity date to be well before midsummer or after. Sow spinach in late July and August and you’ll have a much better chance of a crop than sowing it in May.
When to sow autumn crops
So now you know that to grow autumn crops you need to choose the right varieties of veg. Leafy greens will be your friend since they are quick to mature. You can also take advantage of many of them being long-day veg so their tendency to bolt will be less. The next thing to calculate is when to sow.
Your region’s first and last frost date will dictate when to sow veg. If you live in the USA, you can find out your dates here. For the British Isles you’ll want to check on this website. Count back the days to maturity for any plant from the first frost date. That day will be the last day you can sow it.
Hacks for Autumn crops
Many autumn vegetables sown from seed will tend to be green and leafy. Think lettuces, Asian greens, and cool climate herbs and leaves. If you’re a little late in sowing, another way to extend the season is to buy plug plants. Many seed companies will still be offering them from late July to August so have a browse. It’s a quick and efficient way of skipping the initial growing time.
You can also encourage new growth on non-woody perennial herbs by cutting them back hard. Herbs like peppermint, lemon balm, lovage, welsh onions, and chives will grow new shoots and leaves up to the first frost. Bring them indoors or under cover if you’d like to extend the season even further.
What to plant for autumn harvests
These are some of the vegetables to grow for autumn harvests. They include a lot of leafy greens like spinach, chard, and oriental veg. Mix and match them for cooler season salads or toss them into a stir fry. Some, like kale and lamb’s lettuce, can stand through frost and cold. Their growth will slow down but they’ll still give you greens during autumn and winter.
- Arugula Also known as Rocket. This peppery leaf is easy to grow and can be used in all manner of dishes ranging from salads to rice to pizza toppings. 45-60 days to maturity.
- Beet Greens The green tops of beetroot. Though it can take considerably longer for the actual root to develop, you can expect to have beetroot greens ready for picking in as little as a month. The leaves are similar in taste but earthier than Swiss Chard. You can eat them as baby leaves or wait until they’re more mature to harvest. 21-42 days to maturity
- Bok choi / Chinese Cabbage A mild flavored crisp vegetable that can be used both raw and cooked. Though each plant needs about a foot to mature into full size, you can grow ‘baby’ leaves in pots and containers. 25-30 days to maturity.
- Cabbage There are varieties of cabbage that naturally mature in both autumn and winter. Sow well in advance since it takes 50-90 days for them to reach maturity.
- Cilantro Also known as Coriander. Cilantro is a popular herb used in both Asian and Latin American dishes including soups, salads, and ethnic savory dishes. 60-70 days to maturity.
- Kailaan / Gai Lan Thick fleshy cabbage flavored leaves that can be used in stir fries, salads, and other dishes that call for cabbage leaves and greens. When grown in containers you must use the plants in their ‘baby’ state. In open ground they need just over a foot to mature to full size. 60-70 days to maturity.
- Lamb’s Lettuce / Corn Salad This hardy green comes in two varieties. One you sow in late summer and it gives you tender greens in autumn. The other is a winter-hardy variety. 50-70 days to maturity.
- Lettuces There are dozens of different types of lettuce but most will give you an autumn harvest. For extending the season, look for varieties that are winter hardy. 40-60 days to maturity.
- Mibuna An Asian vegetable with a peppery, mustardy flavor. It’s used in stir fries but is more commonly uncooked and used in salads or as toppings for savory dishes. 40-50 days to maturity.
- Mizuna Similar to Mibuna, this Japanese green resembles Arugula (Rocket) and is used predominantly in salads and uncooked dishes. 40-50 days to maturity.
- Mustard Greens Hot and peppery, use Mustard Greens in salads, stir-fries, and other dishes that need a little heat. Keep in mind that while the baby leaves are tender and flavorful, more mature leaves can be bitter. 30-40 days to maturity.
- Pak Choi An upright succulent green with fleshy bases and robust green leaves. Very mild flavor. 45-75 days to maturity.
- Peas It’s possible to get a second crop of peas in the autumn. In July and early August sow varieties that are resistant to hot weather and disease like powdery mildew. 70-90 days to maturity.
- Radishes Juicy and peppery, radishes are a relatively trouble-free vegetable that loves cooler conditions. Autumn conditions are perfect for these tasty and colorful little root veggies. 30-60 days to maturity.
- Spinach You might find that it’s a lot easier growing spinach as an autumn crop due to the long-day information above. 35-45 days to maturity.
- Swiss Chard This green grows fast and can stand all winter long in mild climates. You can even get a flush of new green leaves the following spring. 40-60 days to maturity.