Daucus carota var sativus
This cool season biennial was probably first domesticated somewhere in the region of Afghanistan. It didn’t get its familiar orange color until it arrived in Holland however. As you probably know the orange color is caused by carotene (a precursor of vitamin A), so the redder the root the more nutritious it is.
Crop value: Carrots are a great crop for those seeking to be more food self-sufficient. They are very nutritious, don’t take up much space, are highly productive, relatively fast growing, store well and can be left in the ground for months. You may also be surprised to find that your home grown carrots generally taste better than those you can buy (or maybe you wouldn’t.)
Ease of growing: Carrots are fairly easy to grow if you give them what they need. For best results you want them to grow quickly, without any interruption in growth. Good soil and prompt weeding and thinning are the keys to growing good carrots. Take care of these and you should succeed, neglect them and you may well fail.
Nutritional content: Carrots are famous for their high content of beta carotene, which the body converts into vitamin A (this is not only an important vitamin, but also a powerful antioxidant). They are also a good source of potassium and contain calcium pectate, which can lower blood cholesterol. Eating 4 raw carrots daily has been known to reduce blood cholesterol level by 10% in only 4 weeks.
As an energy source carrots contain about 190 calories per pound.
Climate: Carrot is a cool season crop, growing best at 60 – 75˚F and able to tolerate some frost. The sweetest carrots are produced when days are warm and nights are cool, as this encourages the storage of sugar in the root. They will grow well enough in warmer weather, but on warm nights (above 70˚F) the plant simply uses up the sugar in growth and doesn’t store it in the root (so it won’t be as sweet).
| About Carrot |
Germ temp: 45 (60 – 70) 85˚F
Germ time: 7 – 21 days
50 days / 41˚F
17 days / 50˚F
10 days / 59˚F
7 days / 68˚F
6 days / 77˚F * Optimum
6 days / 86˚F
Seed viability: 2 – 5 years
Germination percentage: 50%+
Growing temp: 55 (60 – 70) 75˚F
Plants per person: 30
Plants per sq ft: 16
Days to harvest: 55 – 90 days
Width: 12 – 18˝
Spring crop: 2 – 4 wks before last frost
Fall crop: 8 – 12 wks before first fall frost
Yield per plant: 2 – 6 oz
Yield per sq ft: 1 – 2 lb per sq ft
pH 6.0 (6.5) 7.0
The soil makes a big difference in how well carrot will grow (how big it gets and how sweet and tender it is). The most critical factor is porosity; a loose soil can increase the size of the roots by as much as 100%. The ideal soil is a light, humus rich, well-aerated, well-drained sandy loam, that is free of stones and fairly neutral. They don’t like acid soil, heavy clay or compacted soils of any kind.
Soil preparation: Prepare the soil by loosening it to a depth of 10˝ and removing any large stones and other debris (these may cause forking). Incorporate organic matter in the form of compost or aged manure. You should also add wood ashes or greensand (for potassium), colloidal phosphate (for phosphorus) and kelp (for trace elements). Or to simplify things you could just use a complete fertilizer mix.
Carrot isn’t a very heavy feeder and too much nitrogen may be a problem by stimulating top growth, at the expense of root growth.
Though aged manure is good for growing carrots, you should never use fresh manure, as it may cause them to fork and grow hairy feeder roots. If you only have fresh manure, then add it the previous fall so it can age over the winter.
If your soil is heavy, or compacted, the best solution is to double dig and incorporate lots of organic matter and then make raised beds. If this is too much work, you could grow your carrots in narrow trenches, filled with a special soil mix. If even this is too much, you could use a short stubby variety.
An easy way to ensure a good soil for carrots is to precede them with potatoes. The soil will have been heavily amended and deeply dug and any organic matter will have aged nicely. They can also follow Brassicas, or any other crop that was heavily manured.
Where: Carrots need full sun for best production, though are a fairly adaptable crop and may do okay in part shade. They also like a fairly warm soil.
Crop rotation: Don’t plant them where any member of the Apiaceae family (celery, parsnip, parsley) has grown in the last 3 years.
When: It is possible to have carrots year round if you plan carefully. They prefer fairly cool growing conditions and the conventional wisdom says they get bitter or acrid in hot weather (above 80˚F). A lot depends upon the variety however.
Spring: Plant your first carrots as soon as the soil is ready to be worked in spring (it should be at least 45˚F), which may be 2 – 4 weeks before the last spring frost. You can start them a few weeks earlier, if you plant them under cloches. Just be careful they don’t get so big they are vernalized.
Autumn: Fall carrots should be sown from mid to late summer (a minimum of 8 – 10 weeks before the first frost) to give them plenty of time to mature before it gets too cold.
Winter: In mild climates carrots will grow right through the winter. They must be started early though, so they are almost mature by the time the first frost hits. They will then continue growing slowly all winter. If they are too small when cold weather arrives, they will simply sit in the ground until spring and then bolt.
Make one large planting for winter use, as you will be eating them for months.
Succession sowing: Carrots are in demand for the kitchen at all times, so it’s a good idea to succession sow them regularly, every 4 – 6 weeks. They stay in the ground in usable condition for a while, especially in cool weather.
Spacing: The right spacing for growing carrots depends upon the fertility of the soil, the type of carrot and the size of the root you want (a wider spacing results in larger roots).
5˝ (poor soil)
3˝ (good soil)
1½˝ (excellent soil)
1˝ (Baby carrots)
Row spacing: If you are planting in rows, you should sow the seeds about ½˝ apart, in rows 18 – 24˝ apart. These are then gradually thinned to a spacing of 3˝ or so.
Indoors: Carrots are quite hardy and don’t like transplanting, so starting indoors isn’t even worth trying. If you insist on trying, then use cell packs or soil blocks to minimize root disturbance.
Outdoors: A seedbed for carrots should have a fairly fine tilth and no large stones or other debris. The seeds are pretty slow to germinate (1 – 3 weeks), which means you have to keep the soil moist for quite a long period. To make things worse, by the time the seeds germinate there is usually a healthy crop of weeds to deal with. See below for ways to handle them.
Broadcasting: You can broadcast the seeds ½˝ apart and then cover them with a thin ⅛ – ¼˝ layer of soil. If your topsoil has a tendency to crust, you may want to use a mix of sifted soil and compost.
The main thing to remember when broadcasting is to sow the seeds at the right density. Beginners usually plant too thickly, which wastes seed and necessitates some tedious hand thinning.
Sowing carrot seed is somewhat tricky because it is so small and light. You might try mixing it with sand, to make it easier to distribute it evenly. Pelleted seed is supposed to make it easier to get the right spacing, but I have never used it.
Rows: I favor planting short rows of carrots across the bed. It wastes less seed, they are easier to thin and it is easier to deal with weeds.
Scrape ¼ – ½˝ deep furrows with a hoe and sow the seed at roughly half the desired spacing. Then close up the furrows, preferably with the same soil and compost mix used to cover the broadcast seeds.
Some people mix a little radish seed in with the carrot seed, to mark the rows and break up any soil crust.
Care of seed beds: It is important to take good care of the seed beds and young seedlings, because (as with humans) the early days can have a big impact on the ultimate harvest.
Watering: It is crucial that the seedbed be watered regularly until all of the seeds have germinated. A general rule is to allow 50% of the surface of the bed to dry out before watering it again.
Sprinkle or spray the bed lightly, if you flood it with water you may slosh the light seeds around. This will result in an uneven stand, with bare patches and very dense patches.
In hot weather you can reduce the frequency of watering (and save water) by temporarily covering the soil with burlap or cardboard. This keeps the soil cool and slows evaporation. Of course it must be removed as soon as the seedlings begin to emerge (ideally just before).
Because carrot seedlings take so long to emerge, you usually have a problem with weed seedlings. There are a few ways to avoid a lot of tedious hand weeding.
A few days before you estimate the seedlings will start to emerge, you can lightly scrape a spring rake across the bed to kill any plants that have already emerged. This will give your soon-to-emerge seedlings a slight head start on the weeds. You can get a precise idea of the best time to do this by planting a sample patch of seed a few days before the main patch. As soon as the sample patch starts to germinate you should act.
Another useful pre‑emergence weeding technique is flame weeding. The only problem with this is that you need a special flame-weeding torch (and fuel).
The process is simple enough, a couple of days before the seedlings emerge, you quickly (you don’t want to burn the soil surface) move a flame across the bed, heating and killing all of the newly emerged weed seedlings. A significant benefit of this method is that the soil isn’t disturbed, so no new weed seeds are brought to the surface, where they would germinate.
You can also sow seeds under paper tape. The seed is sown in rows in the usual way. The rows are then covered with a strip of opaque paper, such as cash register or drywall tape. This is weighted down with handfuls of soil to keep it in place. A day or so before you expect the seedlings to emerge, you remove the paper, which exposes any weed seedlings that have already germinated. These will be elongated and chlorotic from the darkness and will die when exposed to strong sunlight. This leaves a weed free strip of soil for your seedlings to emerge into. The areas between the strips are hoed in the usual way.
Thinning: After all the seedlings have germinated and are growing well, you will have to thin them. If they are packed too closely together they simply won’t produce swollen roots.
The earlier you thin (and weed) the easier it will be. The initial thinning is done when the seedlings are about 2˝ tall and should leave the plants about an inch apart. If you have a large area to thin, this can be done with a wire rake (carefully!) Simply rake out excess plants.
A second thinning (and weeding) should be done 2 – 4 weeks later. This time you thin to the desired spacing by hand. Some gardeners leave this last thinning until the carrots have begun to size up and then eat them. However this may damage the remaining plants, or attract the dreaded carrot rust fly.
It is important to remove all of the uprooted plants from the area after thinning, as the smell of damaged foliage can attract the carrot rust fly. Ideally you thin on cool cloudy days, or in late evening and water afterward to reduce the smell of carrot.
Weeding: If weeds are not removed promptly they will quickly smother the sparsely leafed seedlings. Your first priority must be to weed (and thin) the newly emerged plants. Weeds will have to be removed by hand from broadcast beds. Row plantings can be hoed if widely spaced, though some hand weeding is usually needed also.
Water: Carrots need a steady and even supply of moisture for good growth. Don’t let the soil dry out.
Too little water may result in excessively hairy roots (produced to search for water), or woody roots with marked rings.
Too much water can encourage excessive top growth and result in poorly flavored roots.
You might want to give the plants extra water when the roots start to size up, as this can boost yields considerably. Be careful however, as too much water after a dry spell can initiate a sudden spurt in growth, which may cause the roots to split.
Feeding: If the soil is poor you may want to give them a liquid feed of kelp or compost tea after all the plants have emerged, and then again a month later.
Mulch: If you are growing in rows a mulch is beneficial to conserve moisture and keep down weeds. It also covers the shoulders of the root, preventing them turning green and inedible from exposure to light.
In cold weather a thick mulch may also help to prevent them being heaved by frost.
Root fail to size up: You may have tried to grow carrots and ended up with lush foliage, but only small spindly roots. This happens when the plant is growing in less than ideal conditions. It produces enough food to survive, but doesn’t make enough of a surplus to store in the root. This may be caused by competition from weeds or other carrots (you neglected to thin sufficiently), insufficient light or water, or from an inadequate supply of nutrients.
Splitting: This is usually caused by irregular watering, too wet, too dry, too wet.
Forking: If you have grown carrots for any length of time, you have probably harvested plants that look vaguely like a human pair of legs (sometimes with other humorously shaped appendages attached). This is known as forking (for obvious reasons) and occurs when the tip of the primary root is damaged in some way (often by contact with fresh manure, insects or stones in the soil). This forces the plant to replace it with two (or more) new growing points and so it forks.
Green shoulders: If the top of the carrot sticks out of the ground and is exposed to sunlight it will turn green and inedible. You can keep this to a minimum by pulling soil up on to the crown of the plant. You can also use mulch to cover the shoulders.
Bolting: Carrots are biennials and don’t naturally flower until their second year. However they may bolt if they get vernalized. This happens when a root is sufficiently large (more than ¼˝ diameter) and is exposed to temperatures below 50˚F for a period of two weeks or more. When warm days arrive it thinks winter is over and flowers.
Carrot Rust Fly (Psila rosae): This is the worst pest of carrots. The larvae (small maggots) tunnel into the root, causing rust colored lesions and rendering the root inedible. In some areas they make it almost impossible to grow carrots without protection. In others it isn’t a problem at all.
The first line of defense against this pest is hygiene. The flies are said to be able to detect the smell of damaged foliage from more than a mile away. Keep thinning and weeding (which bruises the foliage) to a minimum and never leave the foliage lying on the ground.
If this pest is really bad in your area it’s not a good idea to leave the remains of a carrot crop in the ground right through the winter. It can mean a big increase in the incidence of carrot rust fly. In such situations you should dig and compost (or eat) old carrots.
If the fly is severe some kind of barrier is probably the best way to go. Row covers are the commonest solution to this problem, but it’s said that a simple plastic screen, 30 – 36˝ high, around the plants will work just as well. Apparently the flies always stay close to the ground and will try to go around the screen, but they won’t go over it (so long as the bed is no more than 36˝ wide).
There are usually two generations of flies each year, the first in late spring and another in late summer. It is possible to avoid them both by carefully timing the planting and harvesting.
Four rows of onions, to one row of carrots, is said to disguise their smell, as is a mulch of fresh grass, or fresh sawdust.
There are now some carrot fly resistant varieties available. Apparently these work best if some non-resistant carrots are sown next to them, to act as a trap crop.
Other pests: Aphids, blister beetles, nematodes, carrot weevils, wireworms. We all know that cartoon rabbits love carrots; well gophers, groundhogs and deer do too.
Diseases: A number of diseases are occasionally a problem, including: leaf blight, downy mildew, aster yellows, rust and scab.
Nutrient deficiency: A deficiency of boron or manganese may cause the center of the carrot to turn black. You could treat both of these with a foliar feed of compost tea.
When: You can start pulling the roots as soon as they are large enough to be worthwhile. The larger rooted plants tend to give themselves away by having darker foliage. You can also look at the size of the orange shoulders in the ground. The main crop will be ready in anywhere from 60 days onward, depending on the variety.
In the case of carrots, small isn’t necessarily beautiful. Small carrots may be tender, but larger ones are sweeter, better flavored and have a deep orange color, which indicates that they are rich in carotene.
The best time to harvest carrots for maximum tenderness is when their early rapid growth starts to slow down. As the roots get much over an inch in diameter they may start to get woody (though this depends on the variety). This is why they are commonly succession sown.
Immature carrots generally have little flavor because they haven’t had the chance to store much sugar. They can also be quite acrid because the aromatic terpenes (which give carrots much of their flavor) develop before the sugars. Commercial baby carrots are really just varieties with naturally small roots, planted closely together. They are still harvested when mature (unless they are the commercial fake baby carrots that are carved from larger cull carrots).
How: If you plan on harvesting a large quantity of roots, you should water them beforehand to loosen the soil and making pulling easier. In light soil you can simply pull up the roots by gently tugging on the tops. If you do this in heavy soil the tops will often break off, in which case you should loosen them with a fork before pulling. If you want to store the roots it is important to treat them gently, as any damage will encourage rot.
The usual way to harvest carrots is to start at one end of the bed and work your way down (you might also keep the bed protected with row covers).
Any carrot debris remaining after the harvest should be removed and composted. Don’t leave it on the ground near the plants, as the smell of the damaged foliage may attract the carrot rust fly.
After harvest you should remove all but 1˝ of the tops; they may look picturesque but they drain moisture from the roots, causing them to go flabby.
If you are going to store the roots for any length of time, you should leave them in the sun for several hours to kill the root hairs (not too long though). Select only perfect roots for storage and don’t wash them. Damaged roots don’t store well and should be used promptly.
Storage: Carrots usually deteriorate in one of three ways, they either dry out, sprout or rot. If you store your carrots in a cold (below 40˚F), humid place the first two won’t be a problem. Rot most often occurs when the skin is damaged, which allows decay causing organisms to enter. The living carrot has the ability to heal minor wounds and prevent rot, though this declines with age. The rot factor is the reason it is so important to separate out damaged roots and not try to store them.
The best place to store carrots is in the ground. They keep better and it is a lot less work. In mild climates they will continue to grow through the winter and slowly get bigger. You just harvest them as needed. In colder climates the tops will die back when cold weather hits. When this happens cover them with 6 – 12˝ of mulch (this needs to be deep to prevent the ground from freezing).
The roots actually get sweeter in cold weather as some of their starch is converted into sugar. You must dig them before growth starts again in spring, as this will make them woody and inedible. If you can’t store them, then at least use them for juice, rather than wasting them
Mice can sometimes be a problem with in-ground storage (especially under mulch). If this is a problem you might try covering the bed with a wire mesh screen, before laying down the mulch.
You can also store carrots for up to 6 months in a root cellar, at 32 to 40˚F and 90% humidity (their vitamin A content actually increases in storage for several months). Put the roots in a garbage can, or a wooden box, making alternate layers of damp sand and carrots (if you don’t have sand you could also use damp sawdust or peat moss) Make sure the roots don’t touch each other, or they may rot. Also keep them away from apples, which emit ethylene gas and can spoil their flavor.
You can store carrots in a plastic bag in the fridge for several weeks. They can be canned or dried for longer term storage.
Unusual growing ideas
Winter carrots: French market gardeners used to grow carrots right through the winter in the harsh climate around Paris. They did it by planting them on hotbeds of warm manure, covered with cold frames.
Giant carrots: If you want to grow a giant carrot (why?) do it in a section of 4˝ drainpipe, filled with a specially prepared mix of compost, soil and sand. Water it frequently.
Containers: Carrots can do well in a container, so long as it is deep enough (twice the depth of the root), you use the right (short) variety and you keep the soil moist.
Seed saving: Carrot is a biennial, so stores food in its first year and flowers and produces seed the following year. In harsh climates you will have to protect the roots over the winter, either in the ground or indoors. Replant them in the spring and wait for them to flower.
You have to be careful which roots you use for seed production and what pollinates them. Choose your very best roots and make sure they pollinate each other. The flowers are cross-pollinated by insects and will cross with any other carrots (or the very common wild carrot or Queen Annes Lace) within a half mile. This is important, when I neglected to do it I ended up with a whole range of root colors from orange to yellow to white!
Don’t gather seed from early flowering plants, uproot and get rid of them before they have a chance to pollinate the rest. You don’t want to create an early bolting strain.
The best seed is produced on the primary umbel, which is the first to ripen. The second umbel is pretty good too, so take it from these two. When the seed heads are ripe, cut them and leave in a paper grocery bag to dry thoroughly.
Size and shape are the most obvious differences between carrot varieties, with some producing 2˝ spheres and others growing into huge tapered cylinders 10˝ or more in length. There are other differences too, some red varieties are extremely rich in vitamin A, while others may be purple, yellow or even white. There are now quite a few hybrid carrot varieties, bred for uniformity, high carotene content, resistance to carrot rust fly, or for extra sweetness.
The variety you choose will depend upon the soil, climate and the time of year you are planting. Generally the larger types need looser and deeper soil, while the shorter ones can do well in more compact soils. Shorter ones also mature more quickly. Some varieties do much better in cold, others do better in heat, some store better in the ground.
The most important factor in growing sweet carrots is genetic; some varieties are naturally much sweeter than others. If you want to grow sweet and tasty carrots, you are much more likely to be successful if you start with a sweet and tasty variety. A high quality cultivar, can also help you to overcome some of the other problems associated with growing carrots.
Types of carrot
These long cylindrical varieties with blunt ends are some of the best flavored and textured carrots. They are low in terpenes, high in sugar and don’t develop a woody core. They are the best carrots for eating raw, but generally don’t keep very well. They are easy to grow and quite fast maturing, though they do need a fertile soil.
Touchon – My favorite variety, sweet, tender, very finely flavored and doesn’t get woody.
Bolero F1 – A good hybrid carrot.
Merida – A bolt resistant overwintering carrot that can be planted in fall, for harvesting the following summer.
Scarlet Nantes.- The classic Nantes variety.
These carrots have a tapering conical shape. They are quite sweet, but have a fibrous core which makes them better for cooking than eating raw. They do well in shallow, heavy or poor soils.
Danvers Half Long – Fairly short, it does well in shallow soil.
These are short and conical with a broad shoulder. They can be quite sweet and tasty, but they are best used when young as they may develop a woody core with age. They are generally better cooked, rather than eaten raw.
These types aren’t as fussy about soil as the Nantes and Imperator types and do better in heavy, stony and cold soil. They over‑winter well in the ground and store well out of the ground.
Kuroda – Sweet, crisp and quite heat tolerant (73 days)
Red Cored Chantenay – A French classic with deep orange roots
Imperator: These long tapered carrots are bred for commercial use and are the carrots most often found in supermarkets. They store well and can be very tasty, but tend to be tougher than some other types. They do best in a deep, sandy soil and can get quite big. You need to cultivate the soil deeply when growing these types. They are not a good choice for heavy or rocky soils.
Gold Pak – Sweet and tender.
Baby: Most baby carrots aren’t really young carrots, they are simply varieties that don’t grow very big. They may be elongated or round in shape. Their flavor is quite variable, some are good, some not so good. They don’t need a very good soil, so are often used where the soil is shallow, heavy or not very fertile (they are also the best types for container growing). They don’t store well.
Thumbelina – Sweet and tender.
High vitamin A: There are now quite a few of these.
Juwarot – Sweet, crisp and tasty.
A-Plus F1 – Imperator type, sweet.
Healthmaster F1 – Deep red color.
Beta III – Deep red and sweet.
Carrot Fly resistant: These are a fairly new innovation.
Flyaway F1 – Nantes Type, sweet
Resistafly F1 – Nantes type, sweet, stores well
In my house no one wants to eat cooked carrots, so they are almost always eaten raw.
Chemicals called terpenes give the carrot its characteristic flavor, but they need to be balanced with sugars to make carrots that are good for eating raw. Too many terpenes and too little sugar makes for unpleasantly aromatic and acrid roots. Terpenes are broken down during cooking though, which is why cooked carrots are sweeter.
If the top of the carrot is green from exposure to light, just cut it off.
| Roasted roots |
A simple peasant dish
½ lb carrots
1 celeriac (peeled)
1 rutabaga (peeled)
1 large onion
½ cup olive oil
1 tsp. paprika
¼ tsp. dill
Wash the vegetables and chop the potatoes and carrots into 1˝ pieces. Chop the rest of the vegetables into smaller ½˝ pieces. Put the olive oil in a roasting pan and pre-heat in a 450°F oven. Then add the chopped vegetables and seasonings and stir to coat vegetables evenly. Bake for 45 minutes, stirring occasionally to coat the pieces with oil and prevent them drying out and burning. This is just a basic recipe and you can add lots of other stuff (garlic, green onions, tomato, mushrooms for the last 15 minutes, to cook and add flavor.