Fast growing vegetables and herbs to sow in spring

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Okra Image by itlife from PixabayOkra Image by itlife from PixabayIf you have decided to start growing more edibles, for whatever reason, but want super-quick results, I have rounded up some of the fastest growing intermediate season vegetables for spring and early summer, which will produce impressive results in no time. Read all about growing them below.

In South Africa, the intermediate spring season between winter and summer can be very short, and in many regions of the country we sometimes feel as if we have gone straight from winter into summer. For this reason it is vital to get intermediate spring crops like rocket and lettuce into the soil as soon as the weather permits. Intermediate crops are those which prefer warm temperatures - not freezing cold, or extremely hot temperatures.

Many of these crops grow well in pots and can also easily be sown directly into garden beds once the soil temperatures have risen sufficiently in spring for them to germinate quickly. Alternatively, if you have a warm and sheltered place outside, or a heated germination tray, you can start some seeds off early, and transplant them into the garden once all danger of frost is over, but bear in mind that many vegetables like radishes and carrots do not like to be transplanted and do best if sown directly into garden beds.

Most vegetables need good well drained soil and regular watering, and it is vital to prepare the beds thoroughly before planting, removing all stones, and incorporating lots of mature compost and a generous dressing of bone meal, plus a balanced organic fertiliser. In acid soils a dressing of agricultural lime can be added. Look out for worm pellets, called vermicomposting, or volcanic rock dust, which also work especially well with vegetables.  Once the beds are prepared, rake them smooth and level, water well and allow the beds to lie for at least a couple of days before sowing seeds, as certain big seeds like beans can be damaged by direct contact with fertiliser.

Here are three strategies to get the most out of your vegetable and herb garden:

Succession Cropping

Succession cropping is simply the technique of sowing crops at regular intervals for a continuous supply through the growing season. Generally quick-maturing crops are sown every two weeks, or when the first sowing appears above the ground, you can make the next sowing.


Intercropping matches a quick-maturing crop with a slower maturing crop. To achieve this, at sowing time, place a quick-maturing crop next to a slower-maturing crop. While you wait for the “long stayers” to come to harvest, quick-maturing crops will be in and out of the garden and onto the table in no time.

Catch Cropping

Catch cropping fills space and production gaps in the vegetable garden, often found in spring and early summer, or in mid to late summer. These gaps can be filled with quick-maturing crops which will still have sufficient time to come to harvest before the end of the season. For example, cress can take as little as five days from sowing, and radishes as little as three weeks. Best of all, these vegetables don't require much ongoing maintenance, so they're perfect for impatient gardeners, and for beginners who are starting a vegetable garden.

If you're dreaming of harvesting your own home-grown produce but want super-quick results, here are some of the fastest growing vegetables for spring and early summer. All of them can be found in my Plant Index Section and members can click on the highlighted names to read more about growing each one, their health benefits, companion planting, tips on how to use them in the kitchen, and a whole lot more.

Watercress flowering - Image by Alois Grundner from PixabayWatercress flowering - Image by Alois Grundner from PixabayIf you are not a member yet, click here to read more about joining

Watercress is a super-healthy herb which ranks at the very top of many superfood lists. The most flavourful watercress is produced in spring and autumn, but harvesting can continue all year round. This exceptionally fast growing crop will allow you to start harvesting about 3 weeks after sowing by snipping off leaves as required, and the beauty of growing watercress is that cutting the plants will encourage them to grow even thicker. Watercress varieties abound, but the most common home grown variety is Nasturtium officinale, which can be treated as a perennial, but is easiest to grow as an annual.

It is advised to sow cress directly into garden beds or pots, and seeds germinate best in cool but not frigid conditions (10 to 15°C), and because the seeds are so tiny, they need to be lightly broadcast over the prepared site and covered with a thin layer of soil. Keep the planting area moist until germination, which should occur within 5 to 10 days.

Watercress loves a sunny position in the garden, but if you are growing it in very hot and dry summer regions, or in a container, a cooler semi-shaded position would be best. Watercress will grow in a variety of soils, as long as they are moist and organically rich. Potting soil works just fine, but compost, peat moss and even vermiculite can be added. It is important to keep the soil moist at all times, and you may have to water the plants daily.

Radishes - Image by Michaela Wenzler from PixabayRadishes - Image by Michaela Wenzler from PixabayRadishes are well-known as one of the fastest growing vegetables you can have in your garden. 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. The seeds germinate quickly and after only about three or four days after planting you’ll spot the leafy green shoots appearing, and harvesting can begin 21 to 28 days, after sowing, depending on the variety. You can sow another batch as soon as the first batch shows its first ‘true’ leaves, but sow at least every week or two for a constant supply. Radishes can also be grown in small pots or window boxes.

When placing the seeds in soil, make sure you sow them very thinly, and once they have germinated, start thinning them out until they are spaced about 2.5cm apart. Always keep the soil consistently moist but not saturated, as a sudden lack of water, or alternatively, too much water, can spoil the quality of the crop by causing the roots to split open.

Organic gardeners frequently use fast-growing radish alongside, or even interspersed amongst slower maturing crops, using them as markers, or row markers. For example, they are great markers for carrots, beets and Swiss chard, because if sown at the same time, the radish will germinate quickly, and mark where the carrots, beets, or chard are likely to appear some weeks later. The radishes will be ready, or almost ready to harvest by the time the slower crops are just emerging above ground, or when they are still immature and won’t shade the radishes.

Loose-leaf Lettuce Image by congerdesign from PixabayLoose-leaf Lettuce Image by congerdesign from PixabayLettuce also has a great reputation as one of the fastest growing vegetables, and if it is watered regularly it will germinate and develop quickly. Regular watering also ensures that your lettuce is not bitter. Depending on the variety, lettuce can take from 30 to 70 days to mature, but the loose-leaf varieties can be harvested much earlier and continually, by harvesting the leaves from the outside as required. Loose-leaf lettuces are also less susceptible to changes in temperature and make an unusual border to the flower garden, or accent in a pot or window box.

Although lettuce prefers cooler climates, where it grows in full sun, some varieties are bred to be more tolerant of hot weather, so in regions with hot summers, these types can still thrive in a cool, shady corner of your garden, as long as they are watered regularly. Seeds can be sown directly into garden beds or seedling trays, and generally, planting new seeds every 14 days will ensure a constant supply of young salad leaves all season long. Sow the seeds very thinly and thin the seedlings to space them about 15 to 25cm apart, depending on the variety grown. Cover the seeds over lightly with soil and pat the surface of the soil down. Keep the soil moist and weed-free as the seedlings grow.

Lettuce planted together with radishes will help repel flea beetles, and lettuce also grows well with okra, chives, spring onions, carrots, tomatoes and cucumbers.

Spring Onions Image by congerdesign from PixabaySpring Onions Image by congerdesign from PixabaySpring Onions can be sown directly into the soil at any time of the year in South Africa, except in cold regions where sowing in April and May should be avoided. They are easiest when sown directly into garden beds and thinned to space them 7cm apart. Spring onions should be grown quickly, so that the plants can be harvested when the stems are pencil thick, about 90 to 120 days after sowing. For this reason they should be watered regularly and fed lightly every two weeks with a balanced organic fertiliser that is high in nitrogen. Unlike onions, in order to blanch the stems, a hill of soil must be built up around spring onion plants as they mature.

Because onion and garlic leaves and flowers have a pungent smell that naturally repels insects, they are particularly beneficial as a pest repellent in the vegetable garden, and especially for members of the cabbage family, helping repel cabbage caterpillars, cabbage maggots, cabbage worms, Japanese beetles and aphids. Members of the onion family also grow well close to tomatoes, repelling the red spider mites that normally favour tomato plants, and do well with carrots, beets, and lettuce.

Swiss Chard 'Bright Lights' Image by Mabel Amber From PixabaySwiss Chard 'Bright Lights' Image by Mabel Amber From PixabaySwiss chard is just as easy to grow in containers as it is to grow in the ground, and because it will tolerate both cool weather and heat better than most other intermediate season vegetables, it will linger for much longer in the spring and early summer garden than those like lettuce which have a tendency to ‘bolt’. Because it does not thrive under hot and humid conditions, in subtropical regions Swiss chard is only sown during the coolest months.

The beauty of growing chard is that you can harvest the leaves as they are required - it can’t get fresher than that! You can also start harvesting when the plants are only 15 to 20cm tall, by cutting off the outer leaves with a sharp knife, just above ground level. Continue to use this “cut and come again” harvesting technique by continually cutting the largest outer leaves, and leaving the young inner ones to continue growing.

If you want to plant vegetables between other plants in the garden or in containers, Swiss chard 'Bright Lights' with its colourful stems in shades of pink, yellow, red and orange, are perfect filler plants for borders, and will give structure to container plantings. Because Swiss chard is a good companion plant for tomatoes, it is great to use for intercropping, as the chard will be harvested before the tomatoes get too tall. Alternatively, radishes can be planted in between the Swiss chard, as the radishes will also be ready to harvest long before the chard. Beetroot, carrots and lettuce all thrive when comingled with Swiss chard.

Swiss chard grows easily from seed, which has been soaked in water overnight for better, quicker germination. Cover with about 1cm of soil, and thin out the young plants when they are 15cm tall to space them about 25cm apart in rows 30cm apart. If you prefer inter-planting with other vegetables, plant them singly, or in small groups. Chard seeds often come in clusters of 2 to 3 seeds, so some thinning will be necessary to avoid overcrowding. To avoid damaging the small seedlings it's better to cut the plants out when thinning, rather than pulling them out. Chard is sensitive to moisture stress and needs to be watered regularly, especially in hot weather, and if the soil is good, chard usually does just fine without the use of fertiliser, but if your plants seem to be stunted, apply a fertiliser like organic 3:2:1 halfway through the growing season.

Baby Carrots - Image by Zichrini from PixabayBaby Carrots - Image by Zichrini from PixabayCarrot hybrids are available which allow them to be sown virtually throughout the year in South Africa. If the correct varieties are selected for the season in which you wish to sow, the best sowing times in South Africa are as follows: In cold areas which experience heavy frost they are best sown from August to March. In warm areas which experience only light frost they can be sown from January to November. In hot frost-free areas they are sown from February to September, and in the very hot months (October to January) sowing should be avoided. In mild areas carrots can be planted throughout the year.

Ordinary large carrots should be ready to harvest between 60 to 70 days after sowing, depending on the variety grown, And, although any of these large carrots can be harvested before reaching their full size as a more tender ‘baby’ carrot, some extremely fast-maturing baby carrot cultivars have been bred which take only about 50 days to mature. These are ideal to grow in window boxes or small pots, as well as in garden beds, and are highly recommended for smaller vegetable patches. They are perfect to sow in spring and early summer, so they can be harvested before the daily temperatures get too hot, as excessive heat can cause carrot roots to grow fibrous. Sow by spreading the seed thinly over the surface of the soil, and covering with a thin layer of fine soil. Thin the seedlings out as recommended for the variety you are growing

To help keep track of where carrots were sown, sow radish seeds in rows between the rows of carrots.  Carrots planted with any plants from the onion family like spring onions and chives make a very good combination to help keep the carrot fly at bay.  Carrots also enjoy growing near to lettuce, bush beans, peas, Swiss chard and tomatoes, as well as herbs like basil and parsley.

Chives in bloom - Image by Hans Linde from PixabayChives in bloom - Image by Hans Linde from PixabayChives are perfect for the home gardener, even those with brown thumbs! They make a wonderful addition to the flower border if they are allowed to flower in summer; and there are several varieties with beautiful mauve, pink or white flowers. Chives also grow easily in pots on a sunny windowsill, as long as they are watered regularly, and in very hot regions, are shaded from the intense midday sun.

Chives grow easily from seed sown in spring and summer, directly into garden beds or trays. They need a soil temperature of 19°C or more to germinate. Cover the seeds lightly with soil and water gently. Germination will take place in 2 to 3 weeks. Thin the clumps out, allowing about 15 to 20cm between them. Water regularly but do not overwater, allow the soil to go almost dry between watering, then soak thoroughly again.

Chives grow well with just about anything: Grapes, tomatoes, carrots, broccoli, cabbage, eggplant, kohlrabi, mustard, peppers, potatoes, rhubarb, roses, squash, and strawberries, all do better when growing near chives. However, asparagus, beans, peas, and spinach are said to have a harder time when planted near chives.

Beetroot - Image by chandford from PixabayBeetroot - Image by chandford from PixabayBeetroot is sweet and delicious, and like turnips, the entire plant is edible. The leaves make delicious, earthy additions to the salad bowl, but remember to only snip off one or two leaves per plant at a time, or you could impede root production. Beets mature between 8 to 10 weeks after sowing, depending on the variety, and how soon you harvest them. Normal beetroot can be harvested as baby beetroot, allowing them to even be grown in pots. When the top of the beetroot globe starts to show above the soil, it’s time to pull them for eating.

Beetroot is an intermediate to warm season crop but can be grown almost throughout the year in South Africa, with spring to autumn being the best time to sow in frosty regions, and autumn and winter in sub-tropical regions. For successive crops, sow seed every 4 to 5 weeks. Add lots of compost and a sprinkling of organic 2:3:2 to the bed and ensure that the drainage is good.

Soak the seed overnight in water before sowing to speed up germination. Seedlings do not always transplant well so sow directly into your beds 5 to 12cm apart, depending on the variety  being used; and in shallow furrows about 3cm deep. Leave about 20 to 30cm between the rows.

Each beetroot seed is actually a cluster of up to 5 seeds, so it is essential that you thin out the crop when the seedlings are about 5cm high. To avoid damaging the small seedlings it's better to cut the plants out when thinning, rather than pulling them out. Always keep the soil moist but not saturated, as a sudden lack of water can spoil the quality of the crop. Do not bank up the soil against the roots.

Plant a row of brightly coloured marigolds next to beetroot to repel insects and sow dill and caraway nearby to improve the health and flavour of beetroot. Beetroot grows well with chives, onions, lettuce, cucumbers and peas, to name but a few.

Bush Beans Image by Antony Trivet from PixabayBush Beans Image by Antony Trivet from PixabayGreen Beans are one of the easiest vegetables to grow, and although they are a summer crop, they can be put into the ground as soon as temperatures reach about 15°C. They also grow very quickly, and from sowing to harvest dwarf green beans take only about 50 to 60 days.  Dwarf beans can be sown directly into the ground or into pots, so even a small balcony can sport a few.  Even climbing beans can provide a privacy screen on a sunny balcony. Dwarf beans are great to plant at the same time as the climbing varieties, as they will start producing about two weeks before the climbers do, extending the season beautifully. The dwarf varieties start bearing sooner than the runners but the runners continue bearing for longer, so try to sow both regularly for a constant supply.

In cold regions with heavy frost green beans are sown once all danger of cold is over – anytime from late September to October, with successive sowings up until about the end of December or January; depending on your first frost date. In regions with only light frost sowing starts as early as August and continues until January, February, or even March. In hot frost free regions sowing starts from about February and can continue to about August or September. Optimum growing temperatures range between 15°C and 27°C. Ideal temperatures for germination are 20 to 30°C, with minimum of 10°C.  Seeds germinate within 5 to 10 days. For successive plantings sow dwarf beans every 3 to 4 weeks and runner beans every 6 to 8 weeks.

If the herb marjoram is planted near beans, it will help protect them against aphids; and marigolds and petunias help to fend off beetle attacks. Beans also grow well with carrots, beetroot, cucumbers, basil and parsley. Legumes like beans fix nitrogen in their roots and are dug back into the beds once they have finished bearing; making the soil perfect for leafy crops like lettuce or spinach.

Peas Image by Ruslana Babenko from PixabayPeas Image by Ruslana Babenko from PixabayPeas are delicious and easy to grow. There are 2 main types, namely the common shelled peas, and the edible-podded and snap peas that are eaten like green beans and have sweet crunchy pods. Shelled peas should be ready to harvest about 3 months after sowing and edible pods about 2 months after sowing. Harvest the shelled peas once they are plump. Do not allow the pods to become too big and hard, as this will affect the flavour and inhibit the production of flowers. Edible-podded peas must be harvested before the pod is fully developed and still young and tender. Pea plants are very brittle and fruit should be harvested carefully. For successive crops sow every 2 to 3 weeks.

In South Africa peas are planted as an intermediate crop as they do not like our hot summers, and although the vines can take moderate frost, the flowers can only withstand light frost. In very cold regions, peas are sown in late winter to early spring, so that the flowers miss the heavy frosts, but the crop must be harvested by November, before the weather really becomes too hot. In these cold regions plants can be raised in pots or trays and kept in a protected spot until planting out time. In regions which experience only light to moderate frost, you can also plant peas or from mid-February to May, in order to harvest before the worst cold arrives in June and July. In the winter rainfall regions and in the Northern Cape, peas are best sown in March. In the subtropical regions sow them from March to May when the worst of the heat is over, this will allow you to harvest before it gets too hot again in summer.

Pea seed can be sown directly into beds, but they need a well-prepared bed with lots of compost, some well-matured manure and a light dressing of organic 2:3:2. They like neutral to slightly alkaline soil with a pH of 6 to 7.5. Very acid soils must be treated with agricultural lime at least one month before sowing. Do not feed with a fertiliser that is high in nitrogen, as this will promote leaf growth at the expense of flowers and pods. If the beds are prepared well, peas will not need any fertilisers until they start to flower, when an organic fertiliser that is high in potassium like 3:1:5 can be used.

Make furrows about 3cm deep and sow seeds about 20cm apart. Allow about 60cm between rows if they have supports. Bush peas do not have to be staked but are easier to manage in the home garden if they have a support to grow on. The climbers need a support about 2.5m high. Water the bed thoroughly after sowing. There should be enough moisture in the soil to last until the seeds germinate. Overwatering peas at this stage can cause them to rot. When the seedlings are 5cm tall, bank some soil up against them to hold them up and mulch the soil to conserve moisture and keep the weeds down. Peas hate competition and weeds must be carefully removed. Keep the soil moist at all times without saturating it.

Dill, caraway, carrots, lettuce and kohlrabi grow well with peas. Peas do not like growing near onions, garlic, tomatoes, potatoes, leeks or runner beans. Legumes like peas fix nitrogen in their roots and are dug back into the beds as a green manure once they have finished bearing; making the soil perfect for leafy crops like lettuce or spinach.

Cucumbers Image by Alexei Chizhov from PixabayCucumbers Image by Alexei Chizhov from PixabayCucumbers are fast growing, warm season crops, but they are included here because they can be planted as soon as the temperatures reach about 20°C and spring is a great time to get them going. Cucumbers can even be grown in large containers, and depending on the variety grown, can be ready to harvest in about 8 to 10 weeks - they grow bitter with age, so pick them while they’re small and young. 

In warmer regions of the country seed can be sown from spring to mid-summer, and in cold regions from late spring to early summer. In humid subtropical regions they are planted out during the coolest months. In home gardens cucumbers are best trained up a trellis of some kind, at least 2m high. Tie the stems up as they grow and encourage them to bush by pinching out the growing tips, starting when the plants have 6 true leaves. Once they reach the top of the trellis, pinch out the growing tips again, and continually pinch back very long side shoots to encourage more fruiting.

Cucumbers love good air circulation around their leaves, and require well-prepared beds with soil that drains well and is enriched with compost, or well-rotted manure, and a sprinkling of an organic fertiliser like 2:3:2. Only sow seed directly into the soil when soil temperatures are 20°C or higher, or they may not germinate, sowing in clumps of about 3 seeds. Plant at a depth of +-2cm, and allow about 40cm spacing between the clumps. When the seedlings are a couple of centimetres tall you will need to thin out the weakest seedlings from the clumps, leaving only 1 or 2 strong plants. When your cucumbers start to flower feed them with an organic fertiliser like 3:1:5, keeping it well away from the stems of your plants, and water it in well. Feed again after 3 to 4 weeks, and mulch the plants with compost, but don’t let it touch the stems. Water your cucumber plants regularly, as a lack of moisture can lead to poor flower production and wilting of the leaves.

Dill and caraway are said to improve the taste of cucumber crops. Basil is reputed to protect them from downy mildew; and onions, garlic, or chives will also help prevent fungal diseases. Cucumbers will also grow well with beans, cabbage, lettuce, celeriac, celery, and beetroot. They do not, however, enjoy growing near corn, tomatoes, radish, or horse-radish.

Okra plant with pods - Image by Akhara Y from PixabayOkra plant with pods - Image by Akhara Y from PixabayOkra is a tall growing, warm season, annual crop that loves full sun and grows quickly to about 2 meters tall. It is included here for its ease of growth and because in cold regions you need to get it planted as early as possible. Okra produces large, attractive, hibiscus like yellow flowers in summer, making it lovely almost anywhere. It grows vigorously in warm subtropical climates and a single plant can produce up to a 100 pods, and harvesting can begin in as little as 50 to 60 days after transplanting, when the pods are young and tender and about 8cm long. Do not leave the pods on the plant for too long as they get hard and stringy quickly, and picking regularly also encourages the plant to produce more flowers and pods. Pod production diminishes in cool weather.

In cold regions, sow seeds when all danger of frost is over, in rows about 40cm apart, and thinning the seedlings out in the rows until they are spaced about 30cm apart. Okra grows best in good, well-drained soil but will tolerant poor soils and even heavy clay. Although okra is drought hardy once established, for the best results in the garden, it requires regular watering. Feed your plants monthly with a balanced organic fertiliser.

Like okra, cucumbers and melons also love water and rich soil, so these will do well side by side, but don't plant them too close, as all of them need a large amount of sun to ripen. Lettuce makes a good companion for okra because its shallow roots won't compete for nutrients, and the okra plants will provide valuable shade for tender lettuces in hot regions. Basil also requires some shade in hot regions, and therefore grows well with okra, and the basil, with its strong fragrance repels a number of okra pests. Flowering annuals are also good okra companions because they help attract pollinators, plus they make your garden much more attractive.

It's also a good idea to plant some early cool weather crops like peas alongside okra. Your peas will be ready for harvest before the okra plants get big enough to crowd the peas. When you have finished harvesting your peas, to free up space for the okra, cut the plants at ground level, leaving the roots in the soil, because pea plants help fix nitrogen in the soil, and will give the okra a good boost. The tops can also be left on the top of the ground as they will dry our very quickly and make a nice mulch for the okra.

Rocket Flowers - Image by niebieskibanan from PixabayRocket Flowers - Image by niebieskibanan from PixabayRocket has been a popular, healthy salad green and ‘seasoning leaf’ in southern Europe for centuries, and because the plants quickly go to seed in hot summer weather, rocket is treated as an annual herb which grows easily from seed sown in spring and early summer, or in late summer and autumn. If sown in autumn it will take full sun, but in our hot summers it does best in beds that receive morning sun or semi-shade all day.

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. The leaves are best harvested when young and before the plant flowers, as larger mature leaves, and those grown in the hot summer months, are stronger tasting, almost bitter, and must be used in salads soups and sauces with discretion. Sow into seeding trays or directly into garden beds in composted well-drained soil, and thin the plants out to space them about 50cm apart. Rocket will seed itself in the garden, and once it is established is drought hardy and only requires moderate watering during prolonged dry spells.

Rocket, with its white flowers, is petty enough to fill gaps in the flower border, and in the edible garden it acts as a tonic for tomatoes, raspberries, and onions.

I hope this article has inspired you to plant some edibles this season, spring is just around the corner and if you want to get the most out of your food garden this spring and summer, it’s time to start preparing your beds for sowing as soon as the weather permits.