How to Grow Carrot

Botanical Name: Daucus carota

Plant Type: Hardy Biennial

Not just great for your eyesight and rabbits, carrots are actually an ancient crop which has seen great change over the years. Carrots were first cultivated by the Romans for medicinal purposes and were not developed into a food crop until the Middle Ages, the earliest form being yellow, rather than the orange colour we associate with carrots today.  In fact, the orange carrot that we now accept as ‘normal’ was bred by the Dutch as late as the 1600s, after they mixed the then common European white varieties, with yellow and purple carrots which were thought to have originated in Afghanistan – the result, the now familiar orange.

Carrots are a member of the plant family Apiaceae (Umbelliferae), its closest relatives being celery, dill, parsnip, and parsley. A wild form of carrot, known as Queen Anne’s Lace, is still found throughout Asia, Europe, and Africa. Through plants selection and breeding, carrots exist in a range of colours from black through to white, including yellow, orange, red and purple. 

All colours of this popular root vegetable have their beauty and purpose, but orange carrots will always remain the heroes of this group because of their high levels of beta carotenes, which are converted by the body into vitamin A (which is good for eye health). Sow directly in well-drained, cultivated soils, thin when young and water regularly to prevent splitting.

Varieties

Orange varieties of carrot are by far the most common types grown in Australian gardens, and are the highest in carotene, the precursor to Vitamin A. However, increasingly, other colour variations, including white and deep red, are becoming available to Australian gardeners, and are providing colourful additions to the dining room table.

The traditional orange carrot was developed in Holland in the 17th century. All modern varieties of orange carrot are derived from four ancestral varieties, one of which, ‘Early Scarlet Horn’, is still cultivated today. Contemporary carrot varieties form distinctive groups that differ in shape, maturity, preferred growing conditions, and other characteristics.  They are:

• Amsterdam types - small, slender, tapered roots that grow rapidly and mature early.
• Nantes types - long, cylindrical roots that mature early.
• Chantenay types - short, thick roots.
• Imperator types - large, tapered roots.
• Round types - short, stubby roots.

In general, varieties from any group can be successfully grown under a wide range of conditions. The Amsterdam and Nantes types do well in cool climates, while Chantenays prosper when grown in the heat of summer. Chantenays are more susceptible to a number of diseases than the other types. Round types will grow well in soils too heavy for other types of carrot as well as containers and pots. Both round and Amsterdam types are well-suited to produce baby carrots.

Fortunately, there are many open-pollinated varieties of carrot available in Australia. Select individual colours or try growing a mix to bring a little excitement and colour to your table.

Growing from Seed

Sow: sow directly into prepared garden beds. Ensure that the ground is enriched with compost and weed-free, in succession to prolong harvest

Ease of Germination: Medium

Germination Temperature: 5-30°C

Germination Time: 2 – 3 weeks

Spacing: 2-3cm, thinned to 5cm depending on variety

Harvest: 126 days

Yield: from 95 to 315 grams per carrot

Carrots are be established by direct sowing. Seed germinates over a wide temperature range from 5°C to over 30°C; it usually takes several weeks for seedlings to emerge. In the temperate regions of the country, seed can be sown from late winter through to the end of summer. As one moves progressively north, the length of the growing season increases, so that in warmer regions carrots can be grown year-round. Seed should be sown at intervals of 2 cm to 3 cm and sown up to a centimeter deep to prevent seed from drying out. Maintaining high soil moisture levels during its slow germination is particularly important for carrots.

Care and Maintenance

• carrots do best in full sun. They'll tolerate some shade during the hottest months; but in the cooler seasons, they need all the sun they can get.
• sow directly into a free draining finely cultivated soil
• the soil should be loose to help grow long straight carrots
• carrots must be grown from seed to avoid root disturbance
• the seed is fine, so mix with sand to make it go further
• thin seedlings and water as they grow to stop the roots from splitting
• carrots taste best when they are grown quickly 
• you want to keep your carrots free of weeds- the weeds will take nutrients away from the carrots and will cause poor carrot development.

Cultivation

Traditionally, many gardeners grow carrots as a follow-up crop, in well-manured beds previously used to grow nitrogen-hungry vegetables, such as cucurbits, crucifers or tomatoes, thus reducing the risk of forking through excessive nitrogen.

Sun: Full Sun

Pollination: Insect Pollination

Soil: The key to growing perfect carrots is to grow them in a loose, well-drained soil, so that they can develop their roots with minimal resistance. There is a strong correlation between the lightness of the soil and the quality of the carrot. Gardeners with heavy soil or soil with a high clay content can either improve their soil through the addition of sand and gypsum, or perhaps restrict themselves to growing the round varieties. Carrots are also not very tolerant of acidic conditions and perform best in soils with a pH in the range of 6.5 to 7.5.

Maintenance and Additional Care

Carrot seedlings require thinning out a few weeks after sowing to create a spacing between plants of about 10 cm. With the larger varieties, a second thinning should take place a month or so later to create a spacing of 8 cm to 10 cm between plants. After each thinning, mulch heavily to control weeds. 

Companion Planting

Good companions: Beans, capsicum, chilli, coriander, dill, leek, lettuce, onion, parsley, peas, radish, sage, tomato, turnip.

Bad companions: Anise, dill, and Fennel.

Pests and Diseases

Carrots have very few pest and disease issues

The most serious problem that can be encountered by carrot crops is the carrot virus, which produces a mosaic of yellow spots on the foliage and stems. This virus is carried by aphids, with some varieties, such as the Chantenays, being particularly susceptible. Infected plants should be uprooted and burnt. The disease is most prevalent during spring when aphids are particularly active and mobile. One strategy to avoid the problem is to delay sowing susceptible varieties until summer, when aphid numbers have usually declined.

Container Gardening

Choose short, stubby carrot varieties for contains such as ‘Paris Market’ and ‘Oxheart’.  Grow in a free-draining, premium potting mix for vegetables. Water frequently, especially during establishment. 

Harvesting

Depending on growing conditions and variety, baby carrots can be produced in a couple of months, while world beaters may take up to six months to reach maximum size. Carrots can be harvested at any time during the season. Provided the soil is not too heavy and the weather is not overly wet, carrots can be left in the ground through winter and

harvested regularly. In areas experiencing severe frosts, a light covering of hay will provide protection.

Seed Saving

Seed longevity: 3 years

Isolation Distance: 800m

How to Save Seed: Carrot seed is produced in the second year of growth. The carrot will become woody, sending up a flower stalk which produces a mass of white umbels in spring. These will form seed and should be harvested as they start to brown off. If left too late, your seed will spread into the garden. Carefully remove the flower stalks and place in a pillowcase to dry. Once dry, shake the tops of lightly crush the umbels in your hand to release the seed. Store in a cool, dark, dry environment. 

Tips and Tricks for Success

• in the temperate regions of the country, seed can be sown from late winter through to the end of summer. As one moves progressively north, the length of the growing season increases, so that in warmer regions carrots can be grown year-round.
• if carrots are grown in suitable soil conditions, few serious problems are encountered. The roots may sometimes split, and this is thought to occur through inadequate watering, followed by rain or a heavy watering. Regular watering will help to avoid splitting.
• sow carrot seed every 3-4 weeks to ensure a constant supply.