Carrots: origin, growth & propagation
Carrots are crisp, sweet and tasty. They are a favourite of many home gardeners since they can be grown pretty much anywhere, including pots and window boxes. Discover everything there is to know about this colourful root vegetable.
Carrots (Daucus carota subsp. sativus) are extremely easy to care for and so ideal for beginner gardeners. Carrots are popular not just because of their magnificent colours, but also because they are nutritious, easily digestible and have a sweet taste that appeals to children. Read on to learn where carrots originally came from, how to save carrot seeds and whether carrots are hardy.
Carrots: origin and properties
Carrots come in many colours, shapes, and sizes. The exact origin of the carrot is unclear, but it is thought to have originated in northern Africa, western Asia and southern Europe. The parents of our cultivated carrot are also a mystery: it could be a cross between the wild carrot (Daucus carota subsp. carota) and the giant wild carrot (Daucus carota subsp. maximus), both of which are endemic to southern Europe. Another possibility is that today’s orange carrot was bred over many years from the black carrot (Daucus carota subsp. afghanicus), which is native to Turkey. The crunchy and colourful root veggies spread quickly across the globe since they thrive in both temperate and subtropical climates. Carrots were even consumed in the Neolithic period, according to discoveries from diverse regions. Experts believe carrot root colour ranged from cream to purple at the time. The breeding expertise of the Dutch, English, and French during the 16th century most likely gave us the most well-known and popular orange carrot to this day.
The carrot plant belongs to the umbellifer family (Apiaceae) and is closely related to parsnips (Pastinaca sativa), parsley root (Petroselinum crispum subsp. tuberosum) and celery (Apium graveolens). Carrots are biennial plants that develop numerous finely pinnate, arching leaves and a thick taproot up to 80 cm long, in the first year of growth. The carrot root is scarcely branching and contains an extraordinarily high concentration of healthy, colour-producing carotenes. Depending on the variety, the concentration and type of colourants varies, resulting in yellow, white, red to deep purple roots in addition to orange. Find out about the best carrot varieties that come in a wide range of colours in our dedicated article.
In the second year of growth, an elongated flowerhead forms that can reach 1 m in height, from which several double umbels bloom with countless, tiny individual flowers. The flowering period is between May and July. Carrot flowers are usually white to cream-coloured, but some varieties have pale pink to violet blooms. Many insects, especially hoverflies and numerous species of wild bees gather on the umbrella-like inflorescences to feed on the nectar. Carrots are harvested in the first year, since they grow tender, juicy and aromatic roots within a few months, which become tough, dry and bitter upon flowering.
Following pollination, the carrot forms brown seeds: two-part, egg-shaped seed pods with spiky edges. These spiky seeds easily get caught in animal fur, so they spread effortlessly. Purchased carrot seeds are processed to make sowing easier, so they lack the prickly hairy appendages.
In most locations, many carrot varieties can withstand winter frosts provided they have a protective layer of leaves, brushwood or fleece. In locations with harsh winters, however, carrots cannot survive the freezing temperatures, so carrots intended for storage and propagation must be harvested in autumn. When harvesting carrots for winter storage or for seed propagation, there are a few things to keep in mind. Only harvest and store healthy undamaged carrot roots. Eat any carrots that get damaged during harvest straightaway. Cut off the carrot greens, leaving the leaf crown intact. Store the carrots unwashed, ideally in damp sand in a basement, cellar or another cool, frost-free, very humid location over the winter. Be sure to check the location’s humidity throughout the winter – the carrot roots must never dry out completely.
Tip: Not only are carrots vulnerable to winter frosts, but diseases and pests like the carrot fly (Psila rosae) can prevent successful propagation and cultivation. Check out our specialist article to find out our tips on combatting this well-known carrot pest.
Propagating carrots yourself is a time-consuming and labour-intensive task. These biennial plants only produce flowers and seeds in their second year. With some varieties, colder temperatures also lead to premature flowering in the first year. However, avoid reseeding from these carrot plants, since they genetically pass on this bolting tendency to further generations. Replant the carrot roots, which were stored in autumn and over winter, in a garden bed between mid- March and mid-April.
Ideally, use at least 10, preferably 30 carrots of the same variety to ensure good pollination. Recently planted carrots do not have a strong enough root network to absorb water themselves, so it is essential to water them, especially in a drought.
Additionally, carrots are cross-pollinators. It is best to prevent wild carrots or foreign varieties from flowering at the same time or growing within a radius of at least 150 metres. Carrot flower heads grow tall and benefit from being tied to a support or leaned against a structure. The best seeds ripen on the first flower buds, so just snap off later flowering buds. The seeds ripen over several months and are often ready for harvesting from August to October, as soon as the first umbels are dry and brown. To save the carrot seeds, use scissors to snip off entire seed heads, spread them out and leave them to dry at room temperature for two to three weeks. Then, gently rub the umbels with your fingers to detach the carrot seeds. Place the seeds in a paper bag and store in a dark, dry, and cool location. Carrot seeds have a good germination capacity for about two to three years.
Carrots can be planted from spring, all the way into the summer. Learn everything you need to know about growing carrots in our other article.