Cultivation of the Carrot
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There is something very satisfying about growing your own carrots. For a start it is very easy to have a supply of carrots for at least nine months of the year and even longer with a bit of luck and good management.
You will be pleasantly surprised by the flavour of home grown carrots. They might not be as unblemished as those supermarket types but they have a flavour that many modern mass market carrots seem to have lost. It should be no surprise that carrots are the second most popular vegetable in England after potatoes. The average person eats 13lbs a year. If more people realised the true nutritional value they would eat double this amount. Find out about the nutritional values by clicking here.
Golf ball-type carrots (Thumbelina) and the slightly longer Chantenays are good for containers and heavy soils. Short carrots also mature faster, shaving two weeks off the time it takes to put them on the table. Nantes, Imperator and Danvers (and Danvers Half Long) grow up to 7 inches long and are suitable for most other soils. If colour is an issue, Danvers Half Long and Royal Chantenay are bright orange, while Scarlet Nantes and Blaze (an Imperator) are deep orange, almost red.
Why do carrots flower rather than form a usable root? Carrots require cold weather (chilling) to form flowers. If planted too early, this can occur.
Why do some of my carrots form many roots rather than one long root? Carrots form multiple roots (fork) when damage to the primary root occurs. Forking is associated with rocky, stony, or heavy soils. Carrot fly damage can also cause this problem. Deep digging, the addition of compost, and pest control will help reduce this disorder.
I regularly have very pale yellow coloured roots. Why does this happen?
Hot weather and hot soil temperatures are responsible for poor colour formation
in the roots. When temperatures go above 85°F, keep the plants well watered and
mulch around the roots to cool the soil.
More answers here.
The carrot is a cool climate crop and can be sown early in the Spring in temperate climates, or in the autumn or winter in sub-tropical areas. The carrot plant is biennial, that is one which completes its life cycle in two years. It stores in the first year what it is going to use in its second to produce seed. We interrupt its life cycle by gobbling it up in the first year before it has time to reach maturity. In the first year the plant produces the fleshy orange tap root which is eaten. If left in the ground the plant will flower the following spring. Read more about how carrots flower and produce seed here. Read more about hybrid seeds here.
Watch the very informative video from Heritage Seed Library (part of Garden Organic) on how to collect carrot seeds. Here. (YouTube video)
The carrot's fruit is an akene, (a dry indehiscent, one-seeded fruit, formed from a single carpel and with the seed distinct from the fruit wall.) and holds thorns that allows it to remain on the plant during ripening. So called seeds derived from plants in the carrot family are not actually seeds at all, but rather complete fruits that are dried. These include anise, caraway, coriander, dill and fennel.
Not all of the chemical constituents of carrots are for our health; some appear to be there for the health of the carrot itself. One reason that the carrot can be stored for long periods of time, such as over winter in a root cellar, is that the carrot has a mechanism to guard against microbial decomposition (rot).
There are three enemies of carrot storage: wilt, re-growth and rot. The first of these is no problem if the carrot is stored where the humidity is high. The second is of little consequence if the carrot is stored at 0 to 5°C.
The carrot itself contributes much toward conquering the last enemy, rot. At the present time, scientists are busy determining how the disease response mechanism of the carrot operates. There appear to be three lines of resistance which the carrot uses, based on the chemicals contained within the carrot and its skin. Read more about the Carrot Disease Response Mechanism and the contributory elements. Read more about the tastes of carrots. (pdf)
Fast maturing varieties: bred for forcing in cold frames or under cloches. The Amsterdam and Nantes types are shorter than main crop carrot and cylindrical rather than tapered, try Bolero and Ingot.
Stump Root Varieties: such as Early French Frame, these together with the fast maturing varieties often possess good flavour and can be frozen whole.
For tiny gardens and window boxes: try a round sort such as Rondo or Suko. Carrots do well in containers. Choose pots that are at least 12 inches deep and have good drainage. Use potting soil enriched with compost and keep the soil moist. For best results, look for small or "baby" varieties such as Thumbelina, Orbit, Parmex, Oxheart or Little Finger.
Traditional Summer Carrots: these have the prefix Chantenay which are short and squat with a pronounced taper.
For eating over Winter: one of the best in
Autumn King, with a good flavour and long tapered roots, Long Red
Surrey, first introduced in 1834, has to be one of tastiest varieties
as it has a distinctive yellow core, it is out of favour with commercial
growers but well worth growing.
The healthiest Carrot? It's got to be Juwarot containing almost twice the carotene of any other carrot. High carotene carrots you can grow are 'Ingot' (particularly sweet flavour), 'Beta Champ' (great for juicing) and 'Healthmaster' (slow to grow but again quite sweet). Some high carotene carrots also tend to be high in turpenoids which can make some carrots strong tasting and bitter.
If you are allergic to carotene sow White Fodder and you will not be disappointed.
Companion Planting - Carrots do well alongside most plants, especially chives, Rosemary and Sage (which deter Carrot Fly). Dill, Coriander and other members of the Umbelliferae family should not be planted near carrots as they tend to cross pollinate which can be important if you are subsequently trying to save your own seed.
To see an explanation of the various parts of the carrot root, including diagram click here.
Examples of typical carrot root shapes here.
How do carrots produce seeds ?
Carrots are biennial plants and only flower every two years. In the first year the plant produces the edible root and a leafy top. If a carrot plant is left in the ground for another year, it flowers and seeds are produced. If the original carrot was sown using F1 hybrid seeds it may not reproduce properly, or not at all.
Sexual reproduction in carrots is therefore not different from other flowering plants. Pollen is produced and transferred to the female part of the flower, the stigma. The pollen grain then delivers the sperm cells within it to the ovary via a long tube where fertilisation takes place.
The seeds are tiny - a teaspoon can hold almost 2000!
Read more about how carrots flower and produce seed here. Watch the very informative video from Heritage Seed Library (part of Garden Organic) on how to collect carrot seeds. Here. (YouTube video) or download the seed saving guide here (pdf)
Factors Affecting the Colour of Carrots
1. Temperatures above and below the optimum (above 70° and below 60°F) reduce the colour of carrots.
2. Spring and summer carrots are often of better colour than autumn and winter.
3. Carrots grown on sandy soils and soils high in organic matter produce a higher colour than did carrots on silt loams.
4. Excessive water decreases the colour.
5. Reducing the number of daylight hours has reduced the colour.
Colour is more intense in the older portions of the root. It decreases from the epidermis and center toward the cambium, and from the top to the bottom.
Carrots can taste
soapy or bitter - Two ingredients determine a carrot's flavour: sugars and
terpenoids (volatile compounds that impart the carrot flavour). Some varieties
are naturally high in terpenoids, which make the carrots taste bitter or soapy.
Because terpenoids develop earlier than sugars, a carrot that is harvested too
young might taste bitter.
Storing carrots near apples or other fruits that manufacture ethylene gas as
they ripen, encourages the development of terpenoids in the vegetable and
causing them to become bitter when exposed to ethylene.
A lot depends on the growing conditions ( if you grow your own) - the flavour is best if they mature when days are warm and sunny and nights are cool and still. The plant is photosynthesizing like crazy in the daytime and putting a lot of sugars down into the root, then a cool night comes and the carrot 'rests' instead of burning up that sugar. Where the night time temps stay in the 60s or warmer, the plants respire more at night and use up the accumulated sugars. So for the sweetest roots, time your carrot crop to mature at a time of year with warm days and chilly nights. and no matter what the conditions, harvest late in the day rather than in the early morning.
One old wives tale I have heard, but not proven - take 2 pounds of carrots and boil them with three whole cloves and a bit of salt, is supposed to make them sweeter. (if you try this do tell me what you observe). Read more about the tastes of carrots. (pdf)
Carrots prefer light sandy soils so if your garden earth is on the light side you will have no problem. If you garden on clay or stony land then your carrots will always struggle. You will not fail so long as you are careful which varieties you choose - round or stumpy rooted types will succeed practically anywhere, whereas long rooted, tapering types will faulter. Carrots do well in containers. Choose pots which are at least 12 inches deep and give them good drainage. Use potting compost and keep them moist at all times. For best results try small varieties such as Parmex, Oxheart of Little Finger.
If soil or space is a big issue for you please note that Carrots and other root vegetables will grow well in containers as long as the pot is deep enough. Be sure to choose a container that is twice as deep as the length of the carrot at maturity.
The first few weeks after sowing determine the size of your crop. Carrots do not tolerate a deep planting in a dry bed, so the trick is to offer them a shallow sowing with even moisture. The seedlings grow slowly and can't compete with weeds. As they develop top dress with old manure or compost, avoid "hot" nitrogen sources like fresh manure and fish fertilizer as they cause new roots to "burn off" and fork.
Hand weeding is recommended until the carrots are 5cm tall. Thin the carrots to 8cm apart, then mulch with clean straw and compost to keep the weeds at bay.
Mulching also helps the soil retain moisture and prevents "green shoulder," which is caused by exposing the crowns of the carrots to the sun, making the roots bitter. If the tops of your carrot roots start to turn green, pull the soil up around them. Over watering your carrots can cause the roots to crack.
Harvesting - Most carrots can be harvested in less than three months. they can be picked anytime they reach a usable size. The largest carrots will have the darkest, greenest tops, but don't leave the roots in the ground too long or they will be tough. Most are at their prime when about 2.5cm in diameter at the crown.
Do not be fooled by the tops which can be quite bushy but in fact the carrots themselves are quite small. When harvesting, drench the bed with water first, making the carrots easier to pull.
When you find a carrot large enough, grasp the greens at the crown and tug gently with a twisting motion. If the greens snap off, carefully lift the roots with a small fork. Use damaged roots right away and store unblemished ones.
Lifted carrot should not be left on the ground surface for too long as they will attract the attention of carrot fly. Cut the leaves off as soon as they are out of the ground; as long as they are attached they continue to keep growing and draw moisture and nourishment from the roots.
During the first five months of storage, carrots will actually increase their vitamin A content; and, if protected from heat or light, can hold their nutrient content for another two or three months. Since carrots are rich in beta carotene, steaming them makes this nutrient more readily availability to the body as heat breaks down the tough cellular walls that encase the nutrient. The crisp texture of carrots is the result of the cell walls being stiffened with the indigestible food fibres cellulose, hemicellulose, and lignin.
Spring: Sow seeds in February for a forced crop under cloches of cold frame. March April Sow your next crop of Amsterdam Forcing seed outside protected by garden fleece in colder areas. These will be well on the way to maturity as your first crop finishes. recommended varieties Thumbelina, Suko and Baby Sweet.
Summer: June/July Harvest forced types sow late main crops in lighter soil. Crop varieties like Chantenay Red Cored which were sown in March mature in August/September. Recommended varieties King Midas (Imperator type), Kurodo (chantenay), and Nelson nantes type).
Autumn: August/September harvest early unprotected crops. October/November lift and store main crop types on heavier soil. Dig seed beds, remove any stones sow a crop of a forcing variety and protect under a cloche over winter. Recommended varieties: Juwarot and Fly away (nantes types) and Imperial Chantenay and Red Cored which are chantenay types.
Winter: December/January on lighter soil later main crop types can be left in the ground and lifted as needed throughout the period. If the weather is really cold or wet, protect with a covering of straw in early December.
Recommended varieties: Artist and Merida (nantes types) and Camberley and Scarlet Keeper (danvers types).
|1. Preparation||2. Sow the seeds|
|A good mulch of leaf mould applied in autumn is ideal
preparation for growing carrots, helping to create the fine seed bed they
They do not require much feeding. Land that has been composted or manured for a previous crop is preferred.
|These should be sown as thinly as possible 12-20mm deep in rows 150mm apart Space early varieties 100mm apart so they can grow quickly; 50mm apart for main crops. If your soil does not easily turn into a fine seed bed you may find that covering the seed with a mix of sand and leaf mould does wonders for emergence.|
|3. Germination||4. Maintenance|
|This takes about 10 to 12 days depending on soil temperature. You can speed things up by buying primed seed in which the germination process has been initiated by the seedsman. Soon after they have emerged cover ,with a fine mesh netting and leave in place for the entire crop. This will let in light, air and water but keep pests at bay.||Keep the seedlings warm and moist. Keep weeds control.
Thin to 5 cm apart. Keep watering - but too much. Harvest when the top of
the carrot is 2-5cm in diameter.
There is no need to harvest all at the same time. Remove tops before storing. Wash and keep carrots in the fridge in airtight bags to retain moisture.
Here is a guide to
(Useful photos and information
|The Problem||Possible Cause||Action|
|Carrot twist around each other||Plants too close together.||Thin carrots to 2 inches apart when they are small.|
|Carrots rotted or have large white "eyes".||Overwatering.||Water less frequently. Do not plant the carrots in heavy soil.|
|White growth on leaves.||Powdery mildew.||Use fungicide if extensive damage. Sulphur may help.|
|Thin spindly growth.||Competition from weeds/other plants.||Control the opposition.|
|Rotted roots. White fungus on soil surface and on root. Small brown oval honey coloured sclerotia in fungal growth.||Southern blight of white mould. Caused by Sclerotium rolfsii.||Avoid planting in infested soil. Nitrogen rich fertiliser may help.|
|Roots with surface tunnels filled with rusty mush. Stiff white maggots visible but nothing apparent above ground.||Carrot root fly. Lays its eggs in the crown of carrots. Read more here.||Peel off damaged area before using. Harvest carrots as soon as possible. Do not store carrots in ground through winter. Use a soil insecticide to control maggots at planting.|
|Roots hairy, forked or mis-shaped.||Root knot nematode. Overwatering, roots in contact with fertiliser pellets or fresh manure. Hard soil or rocks. Overcrowding.||Rotate. Remove rocks. Thin carrots early.|
|Carrots fail to emerge.||Soil crusting. Soil temperature too high. Seedling pests.||Maintain uniform soil temperature and moisture until seedlings appear. Do not plant too deeply.|
|Yellowed, curled leaves. Stunted plants.||Leafhoppers.||Use insecticidal soap.|
|Brown spots on leaves or roots.||Leaf blight.||Avoid planting in infested soil. Nitrogen fertiliser could help.|
|Tiny holes on leaves.||Flea beetles.||Control weeds. Use rotenone with insecticidal soap.|
|Inner leaves yellowed; outer leaves reddish purple, roots stunted and bitter.||Aster yellows (mycoplasma disease).||Remove affected plants. Control weeds. Use insecticide.|
|Green root tops.||Roots exposed to sunlight.||Cover exposed roots with soil or mulch.|
|All top and no roots||Planted too close together. Excessive nitrogen.||Thin out early. Go easy on the fertiliser|
|Carrots often have forked or branches roots or develop thin secondary roots
Damage to the growing tip of a young carrot. Common causes include soil insects and nematodes which feed on the growing tip resulting in branching of the carrot root. Carrots need a loose, friable soil to develop a good shape. Forking is caused by anything that impedes root growth. This includes nematodes, stones, or heavy, compacted soil. Causes include soil insects and nematodes which feed on the growing tip resulting in branching of the carrot root.
Gardeners are often dismayed when they harvest hairy or misshapen carrots. Imperfect carrots, or carrots with multiple roots – many of them twisted around each other – may come from several causes, including spacing, soil type, fertility, pests and disease.
Your carrots could be overcrowded. Next time, try thinning them to an inch apart after the leaves reach about three inches high.
Did you plant them in clay soil? If you have heavy clay soil, the clay sometimes forces the roots to grow crooked. Amend clay soil in next year’s carrot patch with well-broken down leaves, well-rotted compost. Carrots do well in light (sandy), fluffy soil that is not too full of amendments. Root-knot nematodes may cause deformed carrots. You can either verify this with a soil test and then you might have to solarize (treat soil with the sun’s heat using plastic sheeting in the summer), or rotate your carrots to another area next time.
Did you fertilize right before you planted your carrots? Excess nitrogen (over fertilization) can cause carrots to form multiple roots or get “hairy.” If you add manure-laden compost to your soil, do so in the fall, then let it overwinter before planting carrots in the spring.
Carrot roots will also become hairy in waterlogged ground.
Did you leave your carrots in the ground too long? Carrots are biennials. The first growing season, they grow a taproot. Next they put out secondary roots off the taproot, and then put up the flowering stem the second year. If you planted your carrots last fall, then overwintered them in the ground, they might be sending out whitish secondary roots by now and maybe a stem. Some varieties are more prone to bolting than others.
Cornel University, New York, has a useful list of fact sheets on common carrot diseases - click here.
The University of California has some photos and further detail of common problems. - click here.
Some Sources of Carrot Seed Varieties for United States Home Gardeners - here
William Rubel gives a detailed commentary on the main online catalogues.- here
Salt Spring Seeds (Heritage and Heirloom seeds) - here
Black Carrots - see Carrot Museum Black Carrot page.
Any seeds bought via the links shown below makes a small a contribution to the upkeep of the World Carrot Museum.
Thompson & Morgan
have a tremendous variety of carrot seeds for you to try,
click on the link or banner to buy some.
See photos of common varieties supplied by Thompson and Morgan the leading seed suppliers in the US and UK. Click here.
|Plant Me Now has
a good range
of carrot seeds and other carroty items.
|Garden BargainsGarden Bargains has exactly that, and carrots!|
|Gardening Direct offer a fantastic range of great value, top quality plants, grown under greenhouse conditions and delivered direct to your door. Choose from a fantastic product range including Vegetable seeds and plants and the gardening hardware range.|
Evengreener is the UK's leading manufacturer of water butts and home compost bins. A genuinely 'green' company dedicated to providing useful products to help re-use, recycle and conserve resources.
The next page gives an in depth guide into carrot
cultivation. This includes details on the best types of soil, cropping
information. There is analysis of the number one pest - the carrot fly,
categories of pests and diseases and the detailed classification of carrot
Need advice? try Organic Vegetable Gardening (uk), one of the best vegetable advisory websites in the UK. Their aim is to help gardeners grow their own fresh, tasty vegetables and fruit using dedicated growing guides, and to give advice from fellow gardeners in a friendly forum.
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