Late summer and autumn are great times to sow carrots

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Image by Charlotte Baines from PixabayImage by Charlotte Baines from PixabayHome grown carrots are healthy and full of flavour and texture. In this article you will learn everything you need to know about growing and harvesting them, plus which crops are good companions for carrots. Tasty kitchen tips are also included, plus their health benefits.

Daucus carota is a member of the Apiaceae or Umbelliferae family (both names are allowed by the International Code of Botanical Nomenclature). The earlier name Umbelliferae was given for the arrangement of the flowers on the stem, called an “inflorescence”, which is in the shape of an umbel. Each umbel comprises of many small white flowers with five small sepals, five petals, and five stamens. This family includes many aromatic plants with hollow stems, including the domesticated carrot, parsnip, parsley, cumin, dill, caraway and fennel, amongst others. This family also includes some highly toxic plants like hemlock.

The wild carrot is a variable biennial plant, usually growing up to one meter tall and flowering from June to August in the Northern Hemisphere. The umbels are wine red or pale pink when in bud, opening up to a bright white when their hundreds of tiny blossoms are in full bloom. The umbels can be 3 to 7 centimetres wide with a whorl of narrow bracts beneath, and occasionally they have a single dark red flower in the centre to attract pollinators. Finally, as the flowers turn to seed, the umbels contract and become concave like a bird's nest, giving rise to the plants British common name “bird's nest”.

Wild Carrot Flower. Image by TheOtherKev from PixabayWild Carrot Flower. Image by TheOtherKev from PixabayWild carrots were introduced and naturalized in North America, where they are commonly known as "Queen Anne's lace". The name was given because the flower resembled the lace made by Queen Anne, and the red flower in the centre represented a blood droplet where she pricked herself with a needle when making the lace. The function of the tiny red flower, coloured by anthocyanin, is to attract pollinating insects. Because the wild carrot was introduced into North America as a foreign species, the United States Department of Agriculture has listed it as a noxious weed.

Today wild carrots can still be found in many temperate regions around the world, growing in wilderness areas, along road sides and even on agricultural lands, where they display great diversity. Wild carrots play a valuable role in the ecosystem - the leaves and roots are a source of food for animals, such as larvae of Lepidoptera species which includes butterflies, moths, and skippers, and the flowers provide nectar for bees, which, in turn, pollinate the plants.

Although the domesticated carrot we know today (Carota subsp. sativus) is the domesticated form of the wild carrot, and has been bred for its larger and more palatable taproot, it is still the same species.

Carrot 'Rainbow Mix' Picture courtesy Ball StraathofCarrot 'Rainbow Mix' Picture courtesy Ball StraathofBoth written history and molecular genetic studies indicate that the domestic carrot has a single origin in Persia and Asia Minor, and most scholars agree that all the wild ancestors of the carrot are likely to have come from Afghanistan, which remains the centre of diversity of D. carota. When these plants were first cultivated in Persia (regions of which are now Iran and Afghanistan), they were not grown for their roots but rather for their aromatic leaves and seeds which were used as an herb and medicine. And, long before the wild carrot was domesticated it had already become widespread, and was also used medicinally in the Mediterranean region since antiquity, with seeds found in Europe dating back nearly 5,000 years. Carrot seeds have also been found in Switzerland and Southern Germany dating back 2,000 to 3,000 BC. Early writings in classical Greek and Roman times refer to edible white roots, but these may have also been parsnips, or both. There are white rooted carrots in existence today which are often used as animal feed or a novelty crop, but are nevertheless gaining popularity for public consumption.

The first carrots cultivated for their roots were from the eastern, purple and yellow rooted carrots found in Afghanistan in the tenth century, or possibly earlier, in the region where the Himalayan and Hindu Kush mountains meet. These wild forms developed their purple and yellow roots by being cultivated in several regions where the pH of the soil varied. Some forms contained anthocyanins which made them purple, and yellow coloured roots were lacking in anthocyanins. Anthocyanins are water-soluble pigments that, depending on their pH, may appear red, purple, blue or black, and belong to a parent class of molecules called "flavonoids". They occur in all tissues of higher plants, including leaves, stems, roots, flowers, and fruits, and some of the colours of autumn leaves are derived from anthocyanins. Specimens of the eastern carrot that survive to the present day are commonly purple or yellow, and often have branched roots.

These early cultivated carrots were distributed East and West via the Silk Road - an ancient network of trade routes, formally established during the Han Dynasty of China, which linked the regions of the ancient world in commerce between 130 BCE to 1453 CE.  And so the cultivated carrot spread, and was domesticated in adjacent regions of Russia, Iran, India, Pakistan and Anatolia, reaching Arab occupied Spain in the 12th century, continental North West Europe by the 14th century, and England in the early 15th century.

Carrot 'Cape Market' Picture courtesy Ball StraathofCarrot 'Cape Market' Picture courtesy Ball StraathofThe western orange carrot probably arose in Europe or in the western Mediterranean region through gradual selection within yellow carrot populations. These orange carrots become very popular in the 16th Century, with Dutch and Spanish artists depicting them in paintings of market scenes. In the Netherlands in the fifteenth or sixteenth century, its orange colour made it so popular there that it was used as an emblem of the House of Orange, depicting the struggle for Dutch independence. The Dutch landraces Long Orange and the finer Horn types, first described in 1721, were an important basis for the western carrot cultivars grown at present all over the world.

The orange colour results from abundant carotenes in these cultivars, and although they remain the most popular in the West, other colours, including white, yellow, red, black and purple are becoming increasingly popular with home gardeners. Today carrots come in many shapes and sizes, from long and thin to short and thick, and the roots may be cylindrical, conical, or even spherical in shape. More recently, a number of novelty cultivars have been bred for particular characteristics, and there are several varieties to choose from for the home garden, including small finger carrots which can easily be grown in pots.

Carrots were the first vegetable to be canned commercially, and modern carrot breeders have further refined the carrot, improving its flavour and sweetness, and improving its texture and colour. There have also been significant improvements in disease and pest reduction resulting in ever increasing yields.  Flavour, nutritional and processing qualities are also uppermost in the minds of modern breeders.

In South Africa, there is carrot production in the Western Cape, Gauteng, Free State, North West, KwaZulu-Natal and Mpumalanga.

Cape Market Carrot

Cape Market is a widely adapted, open pollinated variety which is ideal for the home garden and perfect for the bunched carrot market. It has vigorous foliage, with cylindrical-shaped orange roots, 18 to 25cm long, with a blunt to semi-blunt, yet slightly tapered tip. In addition, the roots have a good external and internal colour with a sweet taste. This variety is best suited for late spring to early autumn sowing’s, however it can be sown throughout the year in frost free areas. If sown in spring crops can be harvested from 100 to 115 days. If sown in late summer or autumn crops can be harvested from 125 to 140 days.

Chantenay Karoo Carrot

Chantenay Karoo is an excellent, widely adapted, open pollinated orange variety which is suitable for home gardens and ideal for the bunched carrot market. It produces sweet tasting, wedge shaped roots, 18 to 25cm long, with a semi blunt tip and is not prone to cracking and bolting, and because it is not prone to bolting, it can be harvested over an extended period. It is best suited for spring to mid-summer sowing’s, however seeds can be sown throughout the year in frost free areas.  If sown in spring crops can be harvested from 95 to 115 days. If sown in late summer or autumn crops can be harvested from 120 to 135 days.

Kuroda (Sakata) Carrot

Kuroda (Sakata) is an open pollinated Kuroda type carrot selected by Sakata for its improved uniformity and superior dark orange colour, and sweet taste. It has and average bolting tolerance and the roots are 18 to 20cm in length, and smooth with a wedge shape and blunt tip. It is a great bunching carrot for markets and home gardens, and is also excellent for processing. It is a good variety for warm season production, and is best sown in spring and summer, but is not suitable for cool season crops.  If sown in spring crops can be harvested from 100 to 115 days. If sown later for autumn crops it can be harvested from 125 to 140 days.

Scarlet Nantes Carrot

Scarlet Nantes is a good variety for production in spring and summer, through autumn. The roots are 18 to 20cm long, and fairly smooth with a cylindrical shape and blunt tip, with a good orange colour and sweet flavour. This widely adapted, versatile variety is wonderful for the home garden as it can also be used for young or baby carrots, as well as for larger, mature carrots. It is often used by producers who require young carrots for the pre-packed, fresh market, as well as mature ones, and larger carrots are good for processing. This variety is very slow to bolt and yield potential is high. It is best suited to early cool season production and is best when sown in late summer through autumn. If sown in late summer crops can be harvested from 65 to 70 days. If sown in autumn it can be harvested from 70 to 80 days.

Little Finger Carrot

Little Finger is a wonderful baby carrot with good colour and a sweet flavour. The orange roots are smooth with a short cylindrical shape, and depending on when you harvest them, can be 7.5 to 10cm long with a diameter of 1 to 1.5cm. It is slow to bolt and the yield potential is high. This widely adapted carrot is a versatile variety that is often used by producers who require both baby and slightly larger young carrots for the local and export markets. It can be sown all year round in frost free regions. If sown in spring crops can be harvested from 60 to 80 days. If sown in autumn it can be harvested from 90 to 100 days.

Carrot Rainbow Mix

Rainbow Mix is a delightful kaleidoscope of colourful carrot varieties ranging from orange and yellow to red, purple and white. It includes:  Atomic Red, Bambino, Cosmic Purple, Lunar White, and Solar Yellow. They are all perfect for home gardeners because young baby carrots can be harvested and the rest can be left to mature fully. This mixture of carrots is not only good-looking but also healthy and very tasty, and they are sure to entice children to eat more carrots! Rainbow mix is also a great bunching carrot and guaranteed to attract attention at all specialty and farmers markets. In frost free regions they can be sown all year round. If sown in spring and summer crops can be harvested from 60 to 80 days. If sown in autumn crops can be harvested from 90 to 100 days.

Carrot Parisian

Also known as “Paris Market” and “Thumbelina”, this early French type carrot is a nineteenth-century, open pollinated French heirloom variety, and was probably your great grandparents' carrot as it was widely cultivated by the turn of the century. These heirlooms adapted after hundreds of years of growing in clay soils and are sweet, crunchy and very easy to grow. It is an easy to grow, small round, bright orange carrot, about 2.5cm in diameter, with the shape of a young turnip. The fine grained crisp flesh is almost coreless with a lovely crunch, and its full, sweet flavour is legendary, and highly sought after by gourmet restaurants. Because it also holds its colour for freezing, this variety is perfect for the home gardener, and its unusual shape is sure to attract attention at farmers markets. Because the roots are small and round, this variety is the absolute best for container gardens, and it can even be grown in spots with poor, rocky or heavy soils, as long as some basic soil preparation is done. As its top growth is also smaller than other carrot varieties, it can easily be squeezed into any garden space. An added bonus is that also matures quickly, in only 55 to 60 days, and is frequently forced off season in cold frames and tunnels. It is usually sown in spring and early summer but can be grown throughout the year in frost free regions.

Atomic Red Carrot

Atomic red is native to Africa and Eurasia and produces tapered roots about 20cm long, with a beautiful coral-red skin and an orange core. It is crisp and very sweet, and when you steam, roast, or stir-fry it, the outer colour intensifies and becomes a brilliant scarlet red, contrasting beautifully with the orange core. This variety is considered to be one of the most health giving types because of its high levels of the antioxidant lycopene, which has been shown in studies to help prevent several types of cancer. Cooking them lightly helps to make the lycopene more accessible to the body. In cool summer regions it can be sown throughout the year but in hot summer regions sowing is in very early spring for an early summer harvest, and in late summer to early autumn for an early winter crop. Because atomic red is reasonably frost tolerant seed can be sown outdoors in spring about 2 to 4 weeks before your average last frost date, and for an early winter crop about 8 to 10 weeks before your average first winter frost date. The minimum soil temperature for sowing is about 7 to 8°C, and ideally should not be hotter than about 15 to 25°C. Sow successive crops every 3 weeks to extend the harvest. This colourful carrot is sure to be in high demand once it is seen and tasted, and is a sure way to get your kids to eat their veggies. It can be harvested either as baby or young carrots, or left to mature fully which takes about 70 to 75 days.

Black Nebula Carrot

Black Nebula carrots were developed by a seed company in the United States for home garden use. It is an open-pollinated heirloom variety with elongated roots about 15 to 25cm long, with a slender, conical to cylindrical shape, tapering to a pointed tip. The roots are generally straight, and the skin is a gorgeous dark purple-black, and often covered in many fine root hairs and ridges, depending on the growing conditions. The flesh also a dark-purple colour, and if eaten raw, is crunchy with a mild, bitter-sweet, and earthy flavour. It has a high nutritional content and is an excellent source of anthocyanins, which are antioxidants, and provide anti-inflammatory properties. This variety is favoured by home gardeners as a novel variety and is also often grow as an ornamental in the garden, and used for its beautiful cut flowers. After the carrots grow too large to eat leave them in the garden to produce their lovely white umbels of flowers, which are tinged with lavender on the edges. Black nebula is reasonably frost hardy, and matures in about 75 days. It can be sown every 21 days from early spring through summer and into autumn, ensuring a long harvest window.

Cosmic Purple Carrot

Cosmic purple is an open-pollinated heirloom variety, native to Africa and Eurasia. It has long tapered roots about 20 to 25cm long with a gorgeous dark, wine-coloured skin and its sweet tasting flesh seems to have just a hint of spice, and comes in shades of yellow and orange. It is delicious raw or cooked, and a wonderful variety for home gardeners. At farmers markets it is sure to create great interest. Cosmic Purple is reasonably frost hardy, growing best during the mild temperatures of early spring and summer, and late summer and autumn, maturing in 60 to 70 days or less.

 Lunar White Carrot

Lunar white is a long thin, creamy white carrot with green shoulders, and is almost entirely coreless. It is sought after for its crunchy flesh and lovely mild and sweet taste, and baby or finger carrots can be harvested, or the crop can be allowed to mature fully and the roots are about 15 to 20cm long. If allowed to mature longer, the roots can grow quite large. White carrots were very popular through the 19th century, and when King Henry VIII of England sat down for lunch, the carrots on the table were most certainly white. Sadly, in the 20th century they slowly faded from view, but to the delight of many gardeners they are once again making a comeback, with delicious new varieties like lunar white becoming more freely available. Lunar white matures in about 75 days, but the cooler the soil is the longer it takes for germination. It is quite frost tolerant and can be sown about 3 weeks before your last winter frost date, and in cooler regions sowing can continue through summer. If planted for a summer harvest they will hold in the ground for a few weeks but tend to split if they stay in the ground too long. Late summer and autumn sowings hold longer and the roots become sweeter in the cooler weather. Root quality is best when soil temperatures are between 15 and 22°C.

Solar Yellow Carrot

Yellow carrots have been around for a long time, and the fact that they remain popular to this day makes this ancient heirloom a perfect example of why some heirlooms stand the test of time. Yellow carrots are sweeter than their orange cousins and solar yellow is buttery yellow to the core, and very sweet and juicy. It has a classic Danvers shape that is broad throughout, tapering to a small point. An added bonus is its yellow colour is derived from the pigment xanthophyll which is known to support eye health. It can be harvested as a young or baby carrot but if allowed to mature it will take about 60 to 70 days, growing about 15 to 17cm long.  This yellow carrot is a real stand out at farmers markets or your salad bowl, and well worth growing in the garden. It is quite frost tolerant and does best in the cooler seasons. It is quite frost tolerant and can be sown about 3 weeks before your last winter frost date, or in late summer to autumn for an early winter harvest.

Carrot 'Chantenay Karoo' Picture courtesy Ball StraathofCarrot 'Chantenay Karoo' Picture courtesy Ball StraathofThese unusual carrot varieties are available online in South Africa, so search for your favourite supplier.

Health Benefits:

Carrots are one of the most nutritious vegetables because of their high vitamin A content that improves eyesight. They also contain vitamin C and a good supply of dietary fibre. The roots also contain high quantities of alpha- and beta-carotene, and are a good source of potassium, vitamin B6, vitamin K1, and antioxidants.

A glass of carrot juice a day will lower high cholesterol and help treat and prevent cancer. Carrots are also used to treat anaemia, kidney and bladder ailments, and will reduce heavy metals from fatty tissue. Minor burns and sunburn can be treated effectively with grated carrots or carrot juice; and for oral infections, rinse your mouth 2 to 3 times a day with carrot juice.

With so many health benefits, what is better than to have unlimited access to these delicious and highly nutritious vegetables in your home garden?

In the Kitchen:

There are many exciting ways to use carrots in the kitchen and there is a world of recipes online which will inspire you to use them more often.

“Smoky Carrot Dip” is made with roasted carrots, chickpeas, almonds, lemon juice, garlic, and herbs to produce sweet and smoky flavour that will have everyone going back for more.

“Carrot Fritters with Salted Yogurt” are perfect for vegetarians and because chickpea flour is used, are also gluten-free.

Image by Willfried Wende from PixabayImage by Willfried Wende from Pixabay “Sautéed Carrots with Lemon and Marjoram” makes a simple yet exceptional side dish where the lemon juice and garlic balance out the sweet sautéed carrots with marjoram to perfection. This side dish goes equally well alongside meat, fish, or poultry,

“Moroccan Carrot Salad with Spicy Lemon Dressing” is so easy to make and the addition of Harissa, the North African chilli paste, adds some fiery heat.

“Carrot Macaroni and Cheese” is unbelievably good and the silky carrot puree mixed with cheddar cheese in this recipe is a terrific source of vitamin A, and helps reduce the amount of fat in the recipe.

“Parsnip and Carrot Soup” is perfect if you want to keep it simple, and is the ultimate winter comfort food. This recipe is wonderful with bread or toast, and perhaps even a few slices of cured ham.

Together with onion and celery, carrots are one of the primary vegetables used in a mirepoix to make various broths.

Companion Planting:

Carrot 'Nantes' Picture courtesy Ball StraathofCarrot 'Nantes' Picture courtesy Ball StraathofCarrots planted with any plants from the onion family like leeks, spring onions, chives and garlic make a very good combination to help keep the carrot fly at bay.  Carrots also enjoy growing near to lettuce, radishes, bush beans, runner beans, peas, Swiss chard and tomatoes, and herbs like basil, chervil, parsley, mint, rosemary, rocket and sage. The hairy leaves of comfrey will discourage snails and slugs, so harvest the leaves and mulch your plants with them.

Tip: To help keep track of where carrots were sown, sow radish seeds in rows between the rows of carrots. The radishes will grow quickly and by the time the carrots really start to grow, the radishes can already be harvested.

Bad companions for carrots include dill, fennel, caraway, potatoes, cabbage and cauliflower.

Cultivation and Harvesting:

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.

Modern 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, and in hot frost-free areas they are sown from February to September.

In hot, frost-free areas, avoid planting in the very hot months (October to January). Forked and cracked roots are more common in summer and the central core tends to be thicker. In mild areas they can be planted throughout the year.

Temperature and soil moisture influence the shape, colour and quality of carrots. 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. At temperatures below or above this range, poorer colour develops. The roots also tend to be shorter with less flavour when high temperatures prevail. Insufficient soil moisture results in a longer, thinner root, while very wet conditions have the opposite effect and give rise to a lighter colour.

Carrot 'Paris Market' Picture courtesy Ball StraathofCarrot 'Paris Market' Picture courtesy Ball StraathofAlthough carrots will grow in almost any fertile soil which drains well, they do not do well on acidic soils, preferring a light, sandy soil with a pH of 6 to 6.5. The short or stump-rooted types do better in heavier soil. If your ground soil is heavy clay, or too rocky, you should consider planting carrots in a raised bed at least 30cm deep, filled with airy, loamy soil, or you could plant baby carrots in containers. To prevent misshapen or stunted crops, all root crops require soil that has been thoroughly dug over with all hard clumps of soil broken down and stones removed, and this is especially important for long carrot varieties. When growing carrots at home, don’t expect to get perfectly straight ‘grocery store’ carrots, they may be a bit skew or split but they will still taste better, whatever their shape!

It is not recommended that fresh manure or compost be added to the beds as this may cause unattractive, hairy roots, with a coarser texture. If you practice crop rotation, plant carrots in beds that previously held leafy vegetables, especially cabbages, which are heavy feeders. The compost or manure used to enrich the soil for these previous crops will have sufficiently enriched the soil for growing carrots. If the beds are prepared well and your soil is reasonably fertile it may not be necessary to give any additional feeding. However, in many of the moister areas of KwaZulu-Natal, where the soil is naturally acid and leached, agricultural lime will need to be applied and the crop will require regular fertilisation. 

In poor sandy soils a sprinkling of organic 2:3:2 can be added to the beds before sowing.
Nitrogen requirements of carrots are relatively low, and high rates of nitrogen should be avoided, as this stimulates leaf growth at the expense of root development and yield, and also delays harvesting.  It is generally better to under - rather than over-apply nitrogen.  Very lush leaf growth may also promote the development of diseases. Carrots require a lot of Phosphorous to develop strong good quality roots, and because carrots are frequently grown on lighter textured soils, where leaching is more prevalent, about half the potash is often supplied in side-dressings of fertilisers during the growth period. For the home gardener any fertiliser which is high in phosphates, like 2:3:2, can be applied, usually at 4 weeks, and again at 8 weeks after planting.  An organic slow release fertiliser, like Biogrow ‘Biotrissol’, and bone meal, is also a good organic source of Phosphorous.

Carrots do not transplant well so sow the seed directly into furrows about 1cm deep, leaving about 15 to 25cm between the rows, depending on the variety grown. The smaller varieties grow quicker than the larger ones and can be sown closer together. Carrots are sometimes slow to germinate, and they may even take 2 to 3 weeks to show any sign of life, so don’t panic if your carrots don’t appear right away! Generally, for successive plantings, sow every 3 to 4 weeks, depending on the variety.

Carrot 'Baby Amsterdam' Picture courtesy Ball StraathofCarrot 'Baby Amsterdam' Picture courtesy Ball StraathofThin the seedlings out when they have 2 or 3 true leaves, and thin them once again when they are about 15cm tall, spacing them about 7cm apart, or depending on the variety sown. To ensure that you don’t rip out the others growing nearby, it is better snip off the tops of those you wish to remove with scissors, rather than tugging them out. This will prevent damage to the fragile roots of the remaining plants. Proper thinning is essential as carrots planted too close together will not produce the best quality crop.

Once the crop is reasonably established you may still need to thin out a bit, these baby carrots can be used to make delicious salads. Do not leave carrot crops in the soil for too long as young carrots have a much better flavour than very old ones. To avoid green shoulders to the roots, bank the soil over the roots lightly as they develop. Weed diligently, but be careful not to disturb the young carrots’ roots while doing so.

Carrots need a lot of sunshine to develop good roots, and they also require deep watering about every 5 to 7 days, depending on conditions. Ensure that the soil is wet to a depth of about 30cm. Frequent shallow watering will not produce good results.

Growing carrots in containers:

Growing carrots in containers is easier than growing them in the garden because they thrive on a steady supply of moisture - something that’s hard to provide outdoors in the heat of summer. Baby carrots are especially easy to grow in smaller pots, but longer varieties need deeper pots. To grow short or half-long varieties, choose a pot that is at least 20cm deep, and for standard length carrots the pots should be 25 to 30cm deep. Fill the pot with a fine textured, good quality potting soil, and ensure that the soil drains well. Fill your container with soil to within about 2.5cm from the top. Don’t worry too much about trying to space them evenly around the pot, just moisten the soil and sprinkle the seeds as evenly as you can over the surface and cover with soil to the same depth as for those growing in garden beds. Regular watering is very important, and during germination it is critical because the soil must not dry out. Feeding with a water soluble or foliar fertiliser for vegetables like Biogrow ‘Biotrissol’, mixed at half the recommended strength and applied twice a month is essential as nutrients leach out during watering. Once they germinate, clip out the extra seedlings with a pair of scissors so that the remaining carrots are about 1cm apart. When they are about 7.5 cm tall and you can see which seedlings are the sturdiest, thin them again to space them according to the recommendations on the seed packet.

Carrot 'Little Sweetheart' Picture courtesy Ball StraathofCarrot 'Little Sweetheart' Picture courtesy Ball StraathofHarvesting:

Carrots should be ready to harvest between 8 to 16 weeks after sowing, depending on the variety grown. While any carrot can be harvested before reaching its full size as a more tender ‘baby’ carrot, some fast-maturing cultivars have been bred to produce smaller roots, and these will mature faster than large carrots. Generally smaller carrots have a better flavour than very old big ones, and they can be harvested any time after they develop their mature colour. Tiny, immature carrots are a tasty treat, but you don’t get much carrot for your effort, so you probably want to let at least some of them grow to full size. Harvest by pulling them straight out of the soil, as digging around in the soil disturbs the roots of the remaining carrots and may cause deformities.

If you’re growing carrots in the spring and early summer, harvest before the daily temperatures get too hot, as excessive heat can cause carrot roots to grow fibrous.

Carrots taste much better after one or more frosts because short cold spells will encourage the plant to start storing energy in the form of sugars in their roots for later use. Following the first hard frost in early winter, if you wish to preserve them for harvesting later, cover the tops with a thick layer of shredded leaves for protection.

Note: Carrots are biennial, so if you wish to collect seeds for next season, leave them in the soil to flower.

Storing:

If you have a glut of carrots and wish to store them, twist or cut off all but about 1cm of the tops, and store them, unwashed, in tubs of moist sand or dry sawdust in a cool, dry area. Store them away from apples, pears, potatoes and other vegetables and fruit that produce ethylene gas, because ethylene makes carrots bitter.

You may also leave mature carrots in the soil for temporary storage as long as the ground does not freeze over and pests aren’t a problem.

To refrigerate them, cut off the leaves, scrub off any dirt under cold running water, and air-dry. Seal in airtight plastic bags, and refrigerate. If you simply put fresh carrots in the refrigerator, they’ll go limp in a few hours. Carrots also freeze well.

Problems, Pests & Diseases:

Magnesium deficiency, shows as yellowing of the young leaves, and older leaves will be yellow with green veins. This can be corrected with sprays of magnesium sulphate (Epsom Salts).

Cutworms can devastate a carrot crop so keep a watchful eye out for them.

Aphids sometimes colonize the leaves and crowns of carrots.  These sucking insects may restrict the growth of carrots, although major problems seldom occur.

Red spider mite is also not a common pest of carrots, but numbers can increase rapidly under warm, dry conditions.

Nematodes. Considerable losses can be experienced with carrots because of attacks by root-knot nematodes (Meloidogyne spp). The symptoms are nodular thickenings on the taproot and particularly on the finer lateral roots.  Splitting and forking of roots can occur.  The attacks are generally more severe with carrots grown over the summer months, when higher soil temperatures favour the development of the pest.  Nematodes are often more prevalent on lighter soils.  Various soil fumigants are available for commercial farmers which may be used before planting to control nematodes. However there is not much gardeners can do to eradicate them.

Other soil insect pests  such  as  false  wireworms,  cutworms and  millipedes  sometimes  cause  problems,  by damaging the roots. Earlier harvesting is sometimes justified when damage occurs late in the growth cycle. Crop rotation and the use of bait, as well as frequent working of the soil should reduce pest incidence.

Alternaria Leaf Blight (Alternaria dauci)

Leaf blight is a common disease of carrots in KwaZulu-Natal.  It occurs mainly during wet weather in summer, with prolonged heavy dews frequently promoting severe outbreaks in some areas.  Dark brown to black spots, some with a yellow edge, appear on the leaves.  The spots at  first  appear  mainly  on  the  leaf  edges,  where  they  merge,  so  that  the  leaves  assume  a scorched appearance.  Older leaves are more susceptible than younger ones.  The leaf petioles and the roots can be affected.  The fungus can be transmitted with the seed, and may cause damping-off of the seedlings. In these regions plant cultivars tolerant to the fungus and buy disease-free (certified seed). In areas where blight is known to be a problem, avoid carrot plantings in fields where foliage will not dry quickly after rain or dew, or at times of the year when the disease is more prevalent. Practise a strict crop rotation programme. Fungicide, like Dithane WG or Coppercount, can be used as a preventive measure.

Bacterial Blight (Xanthomonas carotae)

Bacterial blight is favoured by warm, wet weather. Symptoms are easily confused with Alternaria blight, but this disease is less common. Irregular brown spots occur on the leaves, and brown strips on the petioles.  On the roots the disease is characterised by brown, elongated, horizontal lesions. Use of disease-free, certified seed is recommended.

White Mould (Sclerotinia sclerotiorum)

Carrots should preferably not be planted in fields with a known history of the disease.  It is more common in lush, dense plantings and will often start where plants have been trampled or otherwise injured.  Cool, wet conditions favour the disease. A white cottony growth develops on the above-ground parts of the plant.  The shoulders of the roots may also become infected.  The affected plant tissue turns soft and watery. Hard, black resting bodies, called sclerotia, are produced in or on diseased tissue. The disease can develop in harvested produce packed for the market, with individual roots becoming soft and exhibiting the white fungal growth. To control this practise a three-year rotation  with  non-susceptible  crops.  Commonly grown vegetables which are also susceptible to infection by the causal fungus are cole crops, green beans, lettuce and tomatoes. Deep  ploughing  to  invert  the  soil  to  a  depth  of  250  mm  or  more  hinders germination of the sclerotia and hastens their decomposition through antagonism by naturally-occurring soil organisms. Introduce a relatively dry water regime, as wet conditions favour the disease. Remove and destroy infected crop residues. Planting on ridges will improve drainage and allow the soil surface to dry more rapidly. Slash back the foliage to about 150 to 200 mm height and remove this material to allow better drying.

Aster Yellow Disease

Aster yellow disease will cause shortened and discoloured carrot tops and hairy roots. This disease is spread by pests as they feed from plant to plant. Keep weeds down and invest in a control plan for pests such as leafhoppers. This disease has the ability to overwinter.