Daucus Carota var Sativa is one of the oldest and most well-known vegetables in the world. The plant was first popular for its seeds and leaves, used as herbs in prehistoric times. As a (purple) root vegetable, it originated in Asia Minor in the 8th Century. Orange carrots arrived in Britain from The Netherlands during the reign of Queen Elizabeth I.
Carrots were used as a stomach tonic in ancient Greece, and the juice is still considered to be a good remedy for diarrhoea. Carrots have also been used to ease asthma, nervousness and skin conditions, and were said to make hair curly.
The anthocyanin pigments in purple carrots and the beta carotene in orange ones are antioxidants, so carrots may help protect against cancer and other diseases. The beta carotene can be broken down in the body into substances including Vitamin A, which is good for the immune system and the eyes1.
Carrots are biennial2 so all types are grown from seed. There are two main types of carrot – early and maincrop. Early carrots tend to be shorter and cylindrical (or even spherical) in shape and maincrop tend to be longer and more tapered.
Carrots, although very common vegetables, are actually rather tricky to grow. In particular, you need to watch out for carrot fly at all times. If these insects catch a whiff of the sweet-smelling plants, they will lay eggs in the soil and the larvae will tunnel through the roots, causing the leaves to turn brown and ruining the carrot crop.
There are several ways to thwart the carrot fly's mission.
Carefully spacing the seeds will help, so that plants do not grow too closely together3. This reduces the need for thinning out4 in order for large carrots to develop. Disturbing the plants broadcasts the scent and makes it more likely that the carrot fly will find your carrots.
Planting French Marigolds, sage or spring onions amongst your carrots helps to disguise the scent and hide your carrots from the carrot fly.
Covering the area with fine nets when the seeds are planted prevents the carrot flies being able to reach the plants when they grow, but take care if you need to go inside the net, to thin out your seedlings, for example, as some flies may sneak in while you're not looking.
Carrot flies are only little and they don't fly very high5, so another way of protecting your crop is to surround the carrot bed with a metre-high wall of sacking material or similar. You could also plant the seeds in a raised bed or large pot.
There are also an increasing number of carrot fly resistant varieties, which don't smell quite so attractive to the insects.
Once you have decided on your carrot fly repelling method, you need to prepare the soil. In Autumn, choose a spot in a sunny place that has not had manure, compost or other rich fertiliser added in the previous year. For best results, the soil should be sandy and loamy so that it retains moisture and allows the roots to grow downwards with no obstructions.
Early crop seeds can be planted from early March onwards, but the seedlings must be covered with fleece or cloches if there is any danger of frost. The carrots will be ready for harvest from June onwards. Maincrop carrots are usually planted between April and June and harvested from September to October. You can also plant maincrop seeds in August and protect them from frost to enjoy fresh carrots in December.
Use a stick to create shallow trenches 1cm (½in) deep and spaced 15cm (6in) apart. Sow the seeds and cover them with soil. Spacing the rows close together ensures the foliage will cover the ground and help prevent weeds from growing. Water the plants on dry days to ensure the roots do not dry out and then split when it rains again.
Apart from carrot fly, there are several other pests and diseases that could attack your crop:
Swift Moth caterpillars – these white caterpillars live in the soil and eat into the carrots. There is no treatment, so the roots should just be burned and any Swift Moth caterpillars you spot should be removed.
Carrot-willow aphid – these greenfly cause the leaves of affected plants to turn brown and curl up. You could use an insecticide, or remove affected leaves by hand if you spot the insects.
Motley Dwarf Virus – this virus is transmitted by the carrot-willow aphid and causes leaves to turn yellow with red tinges. There is no treatment, but keeping watch for the aphids will prevent it attacking.
Violet Root Rot – this fungus causes some of the leaves to become yellow, but the main effect is on the roots; the carrots are covered in a violet6 felt-like substance. There is no treatment, so the roots should be burned and the ground they were planted in should not be used to grow carrots or asparagus for a year.
Black Rot – this fungus affects harvested carrots that have been stored; the carrots develop large black spots. There is no treatment, although it can be prevented by ensuring that only sound carrots are stored and the storage area is dry and well-ventilated. Affected carrots should be burned and the ground they were planted in should not be used to grow carrots for a year.
Sclerotina Rot – this fungus also affects harvested carrots that have been stored; the carrots are covered by a white cottonwool-like substance. There is no treatment, so the carrots should be removed from the store immediately. The ground the carrots had been planted in should not be used to grow carrots, parsnips or celery for two years.
There are some conditions that do not affect the plants too much, so don't be dismayed if you spot any of these:
Clayburn – if the soil is a mixture of sand and clay, salts in the clay may cause the carrot roots to develop small black spots, but they peel off with the skin so the carrot can still be eaten.
Fanging – misshapen carrots looking like pairs of trousers, hands and even an astronaut have provided entertainment value for a very long time. The fanging is caused by the soil being too stony, not sandy enough or too rich in nutrients, but the carrots are still edible.
Green Top – if the roots are not completely covered by the soil while the plant is growing, sunlight will turn the tops of the carrots green rather than orange. Affected carrots are safe to eat, though (unlike potatoes that have been turned green by exposure to light).
To harvest your carrots, small ones should be able to be pulled straight out of the soil, or you can use a garden fork to gently ease them out of the ground. Carrots should be of a good size if the tops have emerged out of the soil, but the only way to really know how well the plants have grown is to dig them up.
Carrots are very versatile vegetables. Freshly-picked young carrots are best just washed and eaten raw. Larger carrots can be peeled and grated on to salads. Cut them into batons or discs and you can eat them raw, or boil them for 10-20 minutes as an accompaniment to a hot meal. Carrots can be mashed, made into soup or turned into juice. Sliced thinly, they are a great ingredient for stir-fries, or can be baked in casseroles or pies.
If you still have carrots left over after trying all those recipe ideas, they can be stored for later use. Carrots will stay fresh in the fridge for up to two weeks. To keep them for five or six months, take a box full of sand, choose carrots that are not damaged or showing any signs of disease, and bury the carrots in the box, ensuring that there is a layer of sand between each one. Keep the box in a cool, dry shed and check it occasionally to remove any carrots that are no longer in good condition.
Carrots can also be frozen for cooking at a later date – peel and cut the carrots into discs or batons and boil them for five minutes. Drain the water and when the carrots have cooled transfer them into a suitable container and place them in the freezer.
... and Beyond
Some people do more than just eat carrots – the vegetables are popular exhibits in horticultural shows, where people vie to produce the longest, heaviest or simply the best examples of carrot-kind.
Heavy carrots can be grown by leaving them in nutrient-rich soil for as long as possible – they don't have to be beautiful to be winners.
To grow a long straight carrot, you can either dig a deep conical hole or set up a long length of drainpipe at a 45 degree angle, fill it with good soil and plant a few seeds of a long-rooted variety such as St Valery at the top. When the seedlings grow, choose the strongest and remove the others. Spray fertiliser on to the leaves to encourage strong plant growth but not fanging of the roots, and water it regularly. After a year or so, carefully excavate your carrot and see what it looks like.
There is even a virtual Carrot Museum dedicated to everything carrot, from recipes to fine art and toys.