Carrots
Carrots are one of the most popular vegetables, very versatile in cookery and used in a wide range of recipes- soups, casseroles, stir-fries and grated in salads, as well as by themselves. Carrots are easy to grow and do not need a lot of effort, yielding good returns form quite a small space. Home-grown fresh carrots have much better flavour than even the freshest shop-bought kind. Carrots are one of the few vegetables it is possible to grow for use almost year-round because they can be stored in winter. 
Site and soil
Carrots grow best on light sandy soils or soft peaty soils. The common factor between these two completely different soil types is that they have an open airy soil structure. They dislike heavy soil and can be very strong-flavoured in heavy rich ground. However, they can suffer drought in very light sandy or peaty soil. The crop needs a fair level of nutrients in the soil, but not too rich. Ideally, well rotted organic material should be applied a year or two before. Forking of the roots can occur if manure is applied before carrots and this can give woody flavour too. A dressing of general fertiliser can be applied to light soil, about 50 to 80 grams per square metre, but not if the soil is already rich.
Varieties
Carrot varieties can be divided into quick-maturing varieties for early and late sowing and maincrop kinds that develop over a longer period and grow larger. These are also stored. Amsterdam and Nantes type carrots are used for early crops while Chantenay are used for late summer and autumn use and Berlicum and Autumn King types are used in autumn and winter. The Amsterdam and Nantes types are cylindrical, Chantenay types to a lesser extent and the later ones are more tapering and pointed with larger roots.
The older varieties such as ‘Amsterdam Forcing' and ‘Early Nantes' or versions of these are still popular and successful. ‘Nelson' is another good early variety, as is ‘Mokum'. Similarly ‘Chantenay Red-cored' is available, but this type has also been crossed with Berlicum and Autumn king varieties to give better flavour and earlier main crops with better size. ‘Bangor' and ‘Carson' are examples. ‘Red Intermediate' or ‘New Red Intermediate' is a popular and reliable maincrop variety.
‘Autumn King' and ‘St Valery' are typical older varieties, still reliable and good for winter storage. ‘Eskimo' has performed well in trials as a late carrot variety. In recent years, a selection of new varieties showing resistance to the pest carrot fly have been developed. ‘Parano' and ‘Flyaway' are early fly-resistant varieties, ‘Maestro' is a good maincrop and ‘Resistafly' can be stored. A range of round and short stump-rooted varieties, as well as purple, yellow and white forms have been made available, but these are not much more that novelties.
Sowing
The earliest carrots can be sown in cold frames or a greenhouse in late December or early January, using the forcing and early Nantes types to give the first fingerling carrots in May. These varieties can be sown in the open ground in early spring under fleece and the main crop types can be sown from March onwards. Sowing after May tend to run into trouble with carrot fly, but sowing anytime, except the early crops can be affected, as the hatches carrot flies more or less overlap. A sowing with early varieties can be attempted in July or early August for some later fingerling carrots. To achieve continuity, two, three or four separate sowings can be made, using a range of varieties to get a spread of maturity.
Sow carrots into soft, well cultivated fine soil in good condition and not wet. The soil can be drawn up in to drills for the later crops for storing. Sow the seeds in a very shallow drill, about one centimetre deep or less. Use sand to cover the early crops in a frame. Space the rows of carrots about 20cm apart for the early crops, 30 cm for the later ones. Sow thinly to avoid having to thin out much, because the smell of crushed seedlings is thought to attract the carrot fly adult females. Thin out when very small to about 3 to 5cm apart in the row and watch that snails do not graze the rows.
Aftercare
Keep carrots free form weeds by careful hoeing between rows and hand-weeding in the rows. Carrots shade out weeds when the leafy tops have formed, but compete poorly until then. Water the carrots in dry weather but before the ground dries out because the carrots will split if watered after a dry spell.
Pulling and storage
Use the first fingerling carrots when they are just the length of your little finger. These are the most delicious of all. Pulling these allows a thinning and the remaining carrots can be left to grow larger. The earlier sown crops will all be used directly from the garden and only the last maincrop sowing will be used in autumn and stored for winter. Carrots left in the soil are often affected by carrot flies and mushroom flies as well as being attacked by root rot diseases and the top of the roots damaged by frost. Carrots are more likely to remain usable in light, well-drained soil, but late maincrop carrots can be stored too. Traditionally, this was done in a pit or clamp with a layer of straw and soil on top, along with potatoes. The clamp keeps the roots cool and slightly moist too. If an old fridge is available, it makes a very good store. Plastic bags with holes are quite good too, but the roots must have cool conditions or they will sprout. Storage in sand and soil is sometimes recommended but this can create earthy, woody off-flavours in carrots. They can be prepared and frozen too.
Pests and diseases
The main pest of carrots is the carrot fly. The females lay eggs at the stem of the carrot plants and the larvae tunnel into the root and can kill young plants, and spoil mature carrots. The resistant varieties can be used although the resistance is variable. The best solution is a carrot fly fence of polythene or fleece, 50 or 60 cm tall and buried in the soil with no gaps or joins where the flies can enter, as they buzz along at ground level looking for the carrot plants. Greenflies can infest the foliage and can cause a setback and might need to be controlled. Root rots can usually caused by soil that is too heavy and wet and by making the carrots too lush and soft with too much nitrogen and rich organic material such as manure.