Vegetables and herbs to sow and plant in late summer and autumn

Swiss Chard 'Bright Lights' Picture courtesy Ball StraathofSwiss Chard 'Bright Lights' Picture courtesy Ball StraathofThese tasty veggies and herbs are just the thing for a late summer garden that will keep on giving through autumn. It’s also the right time to sow seeds of many slower maturing winter vegetables, so get my list and tips below.

Late summer is a wonderful time to plant and sow vegetables and herbs which love to grow in the intermediate seasons, when the weather starts to cool down after the heat of summer, and before it gets really cold in winter. There are also many traditional slow maturing winter crops like broccoli that are sown in late summer or early autumn, for an early winter harvest. Sowing these into seedling trays and growing them on to plant out come April will ensure early winter crops, while at the same time freeing up you beds to grow fast maturing late summer crops.

Frost Image by Brigitte is happy ... about coffee time :)) from PixabayFrost Image by Brigitte is happy ... about coffee time :)) from PixabayIn order to successfully grow a late summer garden for an autumn harvest, you need to know what the first average frost date is for your growing region. You will also need to know how many days or weeks are required from sowing to harvesting of the crop, so always check the instructions on the seed packet before sowing. Then, working backward accordingly, you’ll know which crops you will be able to get into the ground in order to harvest before the first frost hits. Keeping a gardening diary will help you to remember next season, which plants did best and which times are the best for sowing certain crops.

In subtropical regions late summer, autumn and winter are perfect for growing many crops, including many of those summer ones which simply find the heat and or humidity at the height of summer a bit too much, but which flourish during the cooler months. In these regions of the country it’s time to get cracking on planning and preparing the beds for planting your edible garden now. 

Many root vegetables are perfect to sow in late summer, to harvest before the soil freezes over, and certain varieties of carrots and turnips even do quite well if you leave them in the ground in early winter, covering them heavily with mulch, and pulling them up as required. Turnips last well this way, and certain varieties of carrots actually get sweeter if they’re left in the ground once winter hits. Baby carrots are perfect for an autumn harvest as they mature very quickly and can easily be grown in pots. If you sow beets in late summer, be sure to plant them densely so when you thin the plants out, the delicious young, nutrient rich leaves can be used in salads. Baby beetroot is also absolutely delicious!

Rocket FlowersRocket FlowersLeafy greens like rocket and lettuce are essential to go with your radishes for those wonderful late summer salads, and like radish they often bolt in the summer heat. They all grow quickly, and if you don’t have time to let some varieties of lettuce reach full maturity, types like perpetual lettuce can be harvested early as required and can even be grown to use as microgreens.

I hope this article will inspire you to make the most of your late summer garden. Members can click on highlighted text to read more about the plants mentioned, and if you prefer e-books I am sure you will find “Growing Vegetables in South Africa” & “Growing Culinary Herbs in South Africa” helpful and inspiring.

 Radish seed can be sown almost throughout the year in South Africa, however, in very hot summer regions, high temperatures may cause radishes to bolt, making them essentially useless.  For this reason they are perfect to sow in late summer. Also, in very cold winter regions, June and July are not good months to sow seeds. Radishes are best sown directly into garden beds or pots, and grow so quickly, they should be ready to harvest within 3 to 5 weeks, depending on the variety sown.

 Rocket is an annual herb which grows easily from seed sown in late summer and autumn, or in spring and summer. Because the plants quickly go to seed in hot weather, autumn is a great time to sow rocket if you live in a very hot region.  It is remarkably hardy to frost if it is kept on the dry side, and requires full sun if sown for an autumn or winter crop. Sow into seedling trays or directly into garden beds and the seed will germinate in a couple of days, and within two to three weeks you will be harvesting the leaves - pick the leaves often, the more you pick the more it produces.

 Parsley is often treated as a biennial herb in cooler regions where it can produce leaves for up to one and a half years before it produces it’s pretty yellow flowers and needs replacing. It tends to suffer and may die in very hot, humid regions, where it is better grown as an annual crop during the cooler seasons. Although parsley is hardy to frost, in very cold regions it may die down in winter, and despite the fact that parsley grows easily from seed, germination is slow, taking four to six weeks, so if you want a crop before winter it may be best to plant out established seedlings now.

Lettuce Mix Image by Th G from PixabayLettuce Mix Image by Th G from Pixabay Lettuce often bolts in the summer heat, preferring the cooler intermediate growing seasons,  so sow or plant out your favourite types as soon as the weather starts to cool down. Today hybrid varieties are available that can be sown almost all year round, with June and July being the least favourable months to plant unless you live in subtropical regions, so check your varieties carefully. Perpetual lettuce is so easy to grow, and the outer leaves can be harvested as required. For successive crops sow every 2 to 3 weeks. Butter head lettuce also forms smaller, looser heads, so the outer leaves can be harvested until the inner head has formed. Cos lettuce has a very upright growth habit and forms a head of narrow leaves, but needs cool growing conditions. Butterhead and Cos lettuce should be ready to harvest in 7 to 10 weeks and for successive crops sow every 2 to 3 weeks.

 Endives are more heat tolerant than lettuce and also withstand quite heavy frost, but in South Africa they are still best if treated as a cool to intermediate season crop that is sown in late summer to early autumn. There are two types, the curly leafed varieties and those with broad, flat leaves; their growing requirements are the same as for lettuce, and they can be sown directly into the soil or into seedling trays.

Fennel Bulb Image by fiffe23 from PixabayFennel Bulb Image by fiffe23 from Pixabay Fennel is usually grown as an annual in South Africa.  In cooler regions it can be sown from spring to autumn, but in hot summer regions and those which experience high humidity, soaring temperatures tend to induce bolting, so fennel is generally grown as an intermediate to cool season crop that is sown in late summer and autumn; or early spring. Although fennel is hardy to frost it does not always survive a cold and wet winter, so in colder winter rainfall regions it is usually sown in spring or early summer. Fennel seed germinates quickly and easily from seeds sown directly into garden beds, and the bulbs of Florence fennel are ready to harvest when they are about the size of a tennis ball. Crops sown in early to midsummer will be ready to harvest in about 14 weeks, while crops sown in late summer and autumn may take up to 20 weeks to mature. Remember, they depend on cool weather for bulb development, and if it becomes unseasonably warm, all types of fennel will bolt, meaning it will produce flowers too soon and the bulb won’t form.

 Carrots are moderately hardy to frost and do best under cooler growing conditions, making them a good intermediate crop which is best sown in early spring and summer, or in mid to late summer for harvesting in autumn or early winter. The best quality carrots are obtained when weather conditions favour regular, uninterrupted growth. Plant growth is optimal between temperatures of 15°C to 20°C. Baby carrots are so delicious, mature very quickly, and can even be grown in pots, making them ideal to fill in the gap between late summer and winter crops.

Mixed Baby Carrots. Image by Charlotte Baines from Pixabay ParsnipsMixed Baby Carrots. Image by Charlotte Baines from Pixabay are a cool, intermediate season crop that is best sown in February and March, or in August and September, and although they can take up to 24 weeks to mature, you can start harvesting them before they are fully mature, and should not leave them in the soil for too long, as this will cause them to lose flavour. In hot regions with mild winters, seed is sown in late summer and autumn, however, in extremely cold winter regions, do not sow seed in late autumn or winter as the plants will produce small roots and may run to seed prematurely. Parsnips are best sown directly into garden beds, and the seed must be very fresh for good germination, therefore it is difficult to find seeds in garden centres, however seed can be bought direct from online seed companies.

 Swiss chard is typically grown as an intermediate vegetable crop because it prefers the cooler seasons of spring and autumn. Optimal growing temperatures in South Africa are between 12 and 24°C, with a minimum of 8°C and a maximum of 32°C. However, under hot temperatures, its growth will slow down and the plants will require deep and regular watering. If you are sowing seed in late summer, get it in early as Swiss chard will tolerate intermittent mild frosts, but ongoing frosts may damage the plants. The beauty of growing Swiss chard is that the leaves can be harvested as required.

 Kale is a cool season crop that loves frost, and if established in late summer to autumn, the plants will continue to grow through winter. Kale planted in late summer or early fall may sulk through spells of hot weather, but as soon as weather conditions get colder the plants will take off, quickly. It grows so quickly that you can start harvesting from about 8 to 10 weeks after sowing. The outer leaves can be harvested as required or the whole plant can be harvested at once.

 True Spinach is a favourite winter crop which can handle the cold well and is sown directly into garden beds only in early autumn, as it requires cool growing conditions or it will run to seed quickly. Also, seeds will not germinate well in warm weather, germinating best in soil temperatures between 7°C to 24°C.  You should be able to start harvesting leaves as required about 8 to 10 weeks after sowing.

Peas Image by Tiffany Kay from PixabayPeas Image by Tiffany Kay from Pixabay Peas can take moderate frost but the flower pods can only withstand light frost, so if you live in a region which experiences light to moderate frost, you should plant peas from mid-February to March, in order to harvest before the worst cold arrives in June and July. In very cold regions it is best to sow in late winter to early spring.

 Green Beans will need to get in and be harvested before the first frosts as they don’t handle the cold well. If you do not live in a region which experiences early frosts, you can still get in a crop of bush beans. Most dwarf bush bean cultivars will reach picking maturity within 50 to 60 days, and are harvested earlier than pole beans, so it’s better to plant a bush bean variety later in summer.

 Turnips are best grown as a cool season crop and traditionally they are sown at a time when the main growing period will experience cool weather. The growth period from when the turnip seeds are planted to root bulb harvest is between ten and twelve weeks, so for harvesting during early spring in South Africa, sowing should be in March and early April so that the plants can strengthen before the winter cold sets in and the first frosts arrive. Turnips are hardy to moderate frost and many say that their flavour improves with colder weather, so experiment in your region to find the best sowing times. In regions which experience severe frost, straw can be used as a mulch to protect the roots from freezing.

Beetroot Image by Alexey Hulsov from PixabayBeetroot Image by Alexey Hulsov from Pixabay Beetroot can be grown almost throughout the year in South Africa, but is essentially an intermediate to warm season crop, with spring to autumn being the best time to sow in frosty regions, because beetroot is only semi-hardy to frost, and in cold regions winter sowings will grow slowly with poorer yields. Beetroot will be ready to harvest 8 to 10 weeks after sowing, so you can easily get in a crop before winter.

 Leeks are a good intermediate to cool season crop and are not as fussy about climate as onions. Leek cultivars generally fall into two distinct categories: The so-called ‘summer or autumn leeks’, which are sown in spring for harvesting in late summer or autumn, and the hardier overwintering, or ‘frost-tolerant leeks’. Leeks are slow growing, and although you can start harvesting after about 11 weeks, when the stems are about 1 to 2cm in diameter, they can take 15 to 20 weeks to reach full maturity. Cold hardy leeks are sown from mid-summer to autumn, for harvesting even in the dead of winter in milder winter regions. In extremely cold regions you can extend the harvest season by mulching deeply around the plants, but if you know the approximate date of your first frosts dig them up to store before your first big freeze. Snow acts as an insulator, and if mulched, you could harvest leeks well into winter. Unlike onions, leeks are not day length sensitive, and gardeners in warm climates will tend to find it easier to grow a crop of leeks than a crop of onions. In these regions leeks do well if sown in from March until July, but check which varieties are best suited to your region.

 Garlic may take a long time to harvest, about 8 to 9 months after planting, but because it takes up so little space, even those with small gardens can raise enough to be self-sufficient for a large part of the year. Traditional garden varieties of garlic, just like many flower bulbs, are day-length sensitive, growing best during the cooler months of the year when the days are short and the nights are long. Garlic cloves are planted in late summer or autumn, and harvested the following summer. The increasing day length at the onset of spring will initiate flowering and bulb formation. During this period it is essential that the summer weather is hot and dry, as heavy rainfall, heat and humidity, can cause the bulbs to rot and make the plant more susceptible to fungal diseases. For this reason crops grown in subtropical regions should not be irrigated overhead and must be harvested as early as possible.

Pak Choi Image by MetsikGarden from PixabayPak Choi Image by MetsikGarden from Pixabay Cabbages do very well when planted in late summer as they can handle the winter cold much better than many other vegetables, and don’t forget those delicious Chinese cabbages! The large varieties need lots of space and take longer to mature than the pointed and small round-headed cabbages, and there are early and late maturing types, so choose your varieties carefully.

  Kohlrabi is a member of the cabbage family and the name means "cabbage-turnip" in German. It is essentially a cool season to intermediate crop but is most adaptable, growing in all the climatic zones of South Africa, and can be sown from August to April. Kohlrabi can be harvested after eight to ten weeks when the bulb is about the size of a tennis ball.

  White Stem Pak Choi (Brassica rapa var. chinensis)  is also known as Bok Choy, Hakusai, Bai Cai, and Petsai. It is a very hardy plant with a bulbous base, glossy green leaves and white leaf stalks. The leaves have a mild mustard flavour, and individual leaves can be harvested as required or the whole plant can be harvested when mature. It is grown in the same way as ordinary cabbage, and is a good intermediate to cool season crop which is best if sown directly into garden beds in late summer to autumn.

TatsoiTatsoi Tatsoi is also called Rosette Pak Choi, Flat Cabbage, and Spoon Mustard (Brassica narinosa). This beautiful looking Asian green has a subtle yet distinctive mild mustard flavour, and belongs to the cabbage family. It is a good intermediate to cool season crop which is hardy to frost, and can even be harvested from under the snow, and although more heat resistant varieties are available, tatsoi still grows best if sown in late summer to autumn. It is very easy to grow from seeds sown directly into garden beds and fully mature plants can be harvested in just 45 to 50 days. It can also be harvested at almost any stage, with individual leaves being harvested as required, or the whole plant can be harvested when mature. Many baby leaf varieties also have the capacity to regrow rapidly for multiple cuttings.

  Mizuna (Brassica rapa var japonica )is a good intermediate to cool season crop with pretty, narrow fringed leaves that have a lovely slightly sweet, mustard flavour. Individual leaves can be harvested as required or the whole plant can be harvested when mature. Mizuna is quick and easy to grow, and is best sown in late summer to autumn directly into garden beds or pots.

 Green in Snow Chinese Mustard (Brassica juncea) is an easy to grow, hardy plant that will even survive snow. It is a great spinach standby with a slight mustard flavour, and its dark green leaves are used in salads and stir-fries, and the edible bright yellow flowers have a peppery flavour. Individual leaves can be harvested as required or the whole plant can be harvested when mature. It is a good intermediate to cool season crop which is best sown directly into garden beds in late summer to autumn.

Green in snow Chinese mustardGreen in snow Chinese mustard Red Giant Japanese Mustard (Brassica juncea) is also called “mustard greens” because its red-tinged leaves have a lovely mustard flavour which is great added to stir fries, stews, soups and casseroles. The bright yellow edible flowers are used in salads, and even the sprouted seeds are added to salads. Individual leaves can be harvested as required or the whole plant harvested when mature.

  Broccoli that matures during cool weather produces healthy heads that are sweeter tasting than those you pick at any other time, and for this reason, in our hot climate broccoli is traditionally planted out in late summer or autumn. In fact, the colder it gets the more your broccoli will thrive, tolerating freezing temperatures with ease. Sow broccoli seed into trays in late summer so it can be planted out in April. This will enable the seedlings to get well established before the soil temperature drops, and ensures good early winter crops.

 Cauliflower and broccoli are closely related, and because cauliflower plants are sensitive to excessive heat, as well as sudden changes in temperature, before hybridisation, cauliflower was always sown from mid to late summer to plant out in autumn when temperatures dropped. Today modern hybrids allow us to extend the growing season, and there are early, mid-season, and late varieties available, so choose your cultivars carefully. Sow cauliflower seed into trays in late summer so it can be planted out in CauliflowerCauliflowerApril. This will enable the seedlings to get well established before the soil temperature drops, and ensures good early winter crops.

 Brussels Sprouts have a reputation for being tricky to grow, but it’s quite possible to grow these tasty treats in the home garden if you give them what they need, and if the weather cooperates. Because of their fondness for cool weather and short day lengths, in warm climates Brussels sprouts seeds are sown in late summer, to be planted out into the garden in autumn for a winter crop. They love cold weather and are very hardy to frost. Hot climates where the temperature never approaches freezing, are not really suitable for growing Brussels sprouts. Sow Brussels sprouts seed into trays in late summer to plant out in April. This will enable the seedlings to get well established before the soil temperature drops, and ensures good early winter crops.

 Onions take approximately 28 to 30 weeks to mature, and are ready to harvest when the leaves turn yellow and start to droop. The various types require a specific number of daylight hours and particular temperatures before they will begin to form bulbs. Basically, they are only successfully grown if the right onion is planted for the right area, at the right time. There are ‘short day’ cultivars, others that are classified as ‘intermediate’, and still others as ‘long day’. It is possible to ensure supplies over a longer period by sowing these early, mid-season and late onion varieties, so select yours carefully.

Potato fields Image by Wolfgang Ehrecke from PixabayPotato fields Image by Wolfgang Ehrecke from Pixabay Spring Onion seeds can be sown directly into the soil at any time of the year, except in cold regions where sowing in April and May should be avoided. Unlike onions, in order to blanch the stems, a hill of soil must be built up around spring onion plants as they mature. The plants can be harvested when the stems are pencil thick, about 90 to 120 days after sowing.

 Potatoes & New Potatoes dislike cold conditions and are sensitive to frost, but they also dislike excessive heat, so for home gardens the best time to sow is in early spring or in autumn, depending on climatic conditions. You can ‘chit’ your own to grow, but its best to buy certified seed or tubers as potatoes can suffer from serious fungal and viral diseases. If space is limited you can grow potatoes in a barrel or similar container, and within a short time you can already start harvesting new potatoes. Mature tubers will be ready to lift once the plants have flowered and the leaves turn yellow.