Carrot

• Seeds germinate in ten days, on average.

I recommend sowing direct rather than in modules. However, a difficulty is that carrot seeds are tiny, and early growth can quickly disappear after night-time grazing by slugs or rabbits, even woodlice. Success comes from sowing in beds with no slug habitat nearby, and perhaps with a cover against rabbits. Fleece, for example, can protect early spring sowings from rabbits as well as increasing their speed of growth.

• You can multisow carrots for transplanting. However, this usually causes a break to forked and fanged roots from the all-important taproot. The taproot is your carrot, so it grows shorter and smaller. Multisowing is nonetheless possible for achieving a harvest: sow in deep modules or toilet rolls. Carrots will probably be forked and smaller as a result.

Sowing conditions

Temperature for first sowings

Soil temperature needs to be above a certain level, around 10 °C/50 °F, but there is no need to measure it. Instead, watch for new weeds appearing in your garden – a good sign for your first carrot sowing is when you first notice more than a very few.

• If you know that your carrot bed has many weed seeds waiting to germinate, best delay sowing while you wait for this to happen. Then lightly rake or hoe the surface on a dry afternoon. The delay to your sowing is probably compensated by much easier weeding of carrots.

The date of first sowing will not be in winter. Carrots were actually the first seeds I ever sowed, in January 1981! The seed packet said you could sow from January, outside, and who was I to disbelieve the experts? I now realise that it is rarely expert gardeners who write this advice.

I didn’t harvest a carrot from that sowing in 1981, in fact I never saw any leaves either. Make your first sowing no earlier than the beginning of spring, which here is sometime in March.

Minimise pest habitat

Unless your climate is dry enough that there are very few slugs and snails (or perhaps the soil is sandy, which also means few molluscs), it’s vital that you sow in open ground. There must be no decomposing wooden sides or vegetation nearby, no mulch of hay or straw, not too much long grass along edges, and no nearby containers or dry stone walls. All of these may be habitat for slugs and snails.

I often hear the comment ‘my carrots never came up’. Usually, they would have done, but were eaten rapidly and therefore never seen!

Giving seeds what they need

The soil/compost surface needs to be reasonably fine, but not perfectly so. For example, I never sieve compost for beds, and sow into a surface with many lumps the size of marbles.

This is better than a fine soil surface which can easily be compacted by rain, a process called ‘capping’. The result is a hard layer at the surface, which prevents the emergence of germinating leaves.

• Best spread the compost just before winter, then rake it smooth in early spring. Two separate and quick sessions of raking is good, on dry afternoons – the surface movement serves to kill germinating weed seeds. Here I aim to do it first in late February and then again in mid-March, across all empty beds in fact.

Sowing method

Seeds need to be about 1 cm/0.5 in below the surface level, to keep them moist while germinating. However, if sown too deeply, the tiny carrot seeds may not be able to grow their leaves enough to reach daylight.

1. To make lines in the compost for sowing into, use any of a wooden dibber, a ridging hoe, the corner of a rake, or your fingers. The hollow line is called a drill.
2. Drills can either be along a bed or across it. The advantage of across is that, for beds 1.2 m/4 ft or wider, they make it possible to put your feet between rows to reach the middle.
3. Hold a decent number of seeds in the palm of your hand and then hold the hand downwards, so that seeds trickle into a curved shape made by your four fingers.
4. As seeds descend, rub them between your thumb and fingers so that they fall into the drill, all the while keeping your hand moving along the length of the drill.
5. Rehearse this with some dry sand, before using precious seed.

With some practice, it’s possible to sow quickly and evenly, almost at a walking pace when drills run along the bed.

For sowing larger areas, I would invest in a seed drilling tool. This is economical with seed and gives precise results.

• Nonetheless, you can see that I am growing quite a large number of carrots, just using my fingers. And one of many advantages of handwork is the ease of intersowing between other vegetables.

Once seeds are in place, use a rake or your fingers to level the surface, which results in the drills being filled with sometimes quite dry compost. This is fine, and in dry weather it’s good to walk on the drills, to firm them and conserve moisture.

Spacing

The width between rows for spring sowings can be as little as 15–22 cm/6–9 in. Sow seeds at two per centimetre/five per inch and you can expect about three-quarters of them to germinate. This close spacing gives early harvests from a second thinning after about two months – see below.

Carrots for autumn and winter, which you want to be large, can have 30 cm/12 in between rows. Sow three seeds per two centimetres/seven per inch, and after two to three months thin to about 2.5 cm/1 in between each carrot.

• Once carrots are growing strongly, say after about three or four weeks, you may see that you sowed too thickly, a common experience! It’s worth doing a quick first thin of seedlings wherever you see them in thick clumps.
• The best stage for this first thinning is when you see one or two true leaves – don’t worry to do it too precisely, or you may reduce harvests from the second thin.

Intersow

A huge advantage of this is the gain in season length. Carrot seeds spend six weeks germinating plus growing into small seedlings. During all this time they need very little light and moisture. They also probably benefit from nearby companions.

The intersowing method is the same for all vegetables, apart from adjusting spacings a little so that they can fit between existing plants. My examples below cover the two main seasons of sowing.

Early intersow

If you like eating radish, sow them with early carrots in the same drills for a ‘free harvest’.

• Because the radish emerge quickly, revealing the lines you sowed, this makes early weeding easier between the rows when carrot leaves are barely visible.

It’s important not to sow too many radish seeds because they risk smothering the little leaves of carrots. About one radish seed per 5 cm/2 in is the maximum.

Harvest radishes five to seven weeks later, with a gentle pull to ease them out – this does not damage the more deeply rooted carrot seedlings.

Summer intersow

Carrot sowings in early summer can be between a few different vegetables. Examples are garlic, lettuce which you are picking for outer leaves, and spring onions, depending on how you spaced them.

You can discover more options of different vegetables to sow between. Also of other seeds to sow with your carrots, such as spring onions perhaps.

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How often

Best results come from ensuring that the newly made drills are moist before you sow. In early spring this is not usually an issue, but in summer it’s often worthwhile to walk alongside the newly made drills with a watering can, dropping a decent amount of water into them. Then sow seeds on the moist soil at the bottom of each drill.

After sowing, rake the bed level, often with drier soil or compost above the new carrot seeds. Following that, it’s rare that you need to water for about the first six weeks, as long as the drills were moist.

• Check for the emergence of carrot seedlings within 10 to 14 days – if you do not see many and it is dry, there may not have been enough moisture for seeds to germinate. In this case, give the whole bed a good soaking.
• After that you should not need to water too often. Not before carrots are more than medium size, then perhaps twice a week in dry weather.

How much

Carrots do not need a huge amount of water, and they taste sweeter when soil is a little dry. The amount is about half what you might give to strongly growing cabbage.

Extra mulch to retain moisture?

I do not recommend this for two reasons:

• Any undecomposed mulch before sowing will harbour slugs and woodlice, causing loss of seedlings. However, a compost mulch is fine in this regard.
• Carrot leaves make a dense canopy that retains moisture.

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See above for a first thin of very small seedlings within the first month. The next thin is about one month later – this is the joyful moment of your first harvest!

Look along each row to spot carrots that are grouped more closely to each other than about 5 mm/0.2 in. From any such clumps, choose the larger carrots for harvest. Ease each one upwards, while firmly holding the main stalk, close to the carrot’s shoulder. Sometimes it’s easier to pull two or three together when they are very close and perhaps even intertwined.

With no dig and compost mulch, even on clay soil, it should be possible to pull carrots without using a tool. However, if the soil is hard from being dry, you need to water before each harvest.

• If for any reason a stalk snaps before the carrot pulls out, use any hand tool with a pointed end (trowel/hori hori) and insert it close to the carrot row, vertically downwards.
• With slight leverage, and while pulling the carrot, you can loosen it enough to harvest. Be careful not to lever too much, otherwise you may break the taproots of neighbouring carrots.

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How to judge readiness

One sign is when you see the shoulders of a few carrots above the surface level. They are large enough to be pushing upwards a little, as well as growing downwards. This is the moment to do a first thin for harvest.

• When carrots are nicely spaced, without being overcrowded, you have the lovely choice of harvesting now or leaving carrots to grow larger.
• If new plantings are establishing among carrots, as with Brussels in the photos below, keep pulling the carrots nearest to them, as the Brussels/new vegetables grow and need more moisture.

When to pick and how often

Aim to maximise the use of both bed space and sunlight. Therefore, during the first month of harvests from any one sowing, keep pulling just the largest carrots while leaving their smaller neighbours to grow.

• This maintains a full cover of leaves.
• The effect is enhanced by interplanting of new vegetables, such as Brussels sprouts. For three weeks after transplanting them in the carrot bed, we keep pulling carrots that are close to them, to make more space and still have good leaf cover.

At some point after that, you may want to clear ground or take a large harvest, and then it’s quick to pull carrots from a whole area. Soon afterwards, in this case, the Brussels sprout leaves cover all the surface.

Storing

Even in the warmth of summer, homegrown carrots can store for up to a month. Just leave any soil or compost on them after pulling, and keep in a paper sack somewhere cool.

Storing carrots for winter is exactly the same process. They do not need to be packed in sand, although you can if you want to. Possibly this keeps them a little moister.

• Grade carrots at harvest, to wash and use the small ones first while leaving the large carrots unwashed for storing long term.
• Any stored root vegetable loses moisture over time, becoming softer and slightly shrivelled after three to four months. However, even at this stage, the flavour is excellent, just with a dense texture.
• During or towards the end of winter, wizened roots still have leaves growing out of them, showing that they are alive and good to eat. A similar process to sprouts on potatoes.

Saving seed

From an autumn harvest, you need to select about ten carrots of best size, shape and quality. These are worth storing in sand over winter. Plant them out in March/early spring, 30 cm/12 in apart.

The flower stems are beautiful, and by midsummer their white flowers will have converted to seeds. At this point there’s a risk of seeds falling out,  during a heavy rainstorm for example. Watch for that, and do not grow carrots for seed within about 20 m/65 ft of wild carrots.

It’s a skilled process – do find out more before undertaking it.

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Which pests are likely, and when

There are many, and here are some common ones:

• Slugs cause damage to new sowings, as mentioned above. They eat into carrot roots making round holes, particularly when carrots are in the ground for more than four months from sowing.
• Rabbits and deer are voracious for carrot leaves. The tell-tale sign is a carrot stalk with no foliage on it!
• Rats and mice chew on the shoulders of carrots. You notice small teeth marks, and it’s difficult to say exactly which pest made them.
• Carrot root flies are so small you rarely see them. They lay eggs on soil near to carrots they have found by smelling. The eggs hatch into maggots which tunnel into carrots and keep going around them while eating. This results in a dark circle of rotting carrot. In bad cases, you can lose almost a whole crop – see details below.

Protections needed

Covers solve most of these problems, whether fleece in the spring or mesh in summer. As long as there are no holes, you have protection against carrot root fly. Nonetheless, it seems a few always manage to crawl under the edges of any cover.

Covers such as bird netting also protect against rabbits and deer.

For rodents, you may need to set traps.

For slugs, it’s as I describe above: keep their habitat very, very minimal.

Carrot root fly (Psila rosae)

The flies are rarely seen – shiny, black and 6–8mm/0.2–0.3in long. The most spectacular damage happens to carrots, but all umbellifer roots suffer some eating by the maggots.

Carrots suffer the most because they have a higher surface area, and their flesh is more tender. Parsnip and celeriac, in contrast, have more fibrous bulbs or roots.

There are two hatchings every year, the first one in May and the second one in August to September. The second hatching is often the most numerous, and it’s vexing because carrots for storing over winter may then not store well. If present at harvest time, maggots continue to eat the carrots, even when stored in boxes, socks, or sand.

Ways to reduce damage:

• None are 100% effective, in my experience.
• Cover the whole sowing with mesh. This includes securing the sides more than one needs to for butterfly protection. The cover needs to go on in April and stay on until, say, mid-June. Then, for summer sowings, the cover needs to go on by the second week of August.
• The root flies stay low to surface level, and some gardeners have success with creating a polythene ‘wall’ around their carrots, rather like a windbreak. It needs to be at least 60 cm/2 ft high, and this can be difficult in windy situations.
• It is claimed that interplanting helps to confuse the flies, so they struggle to find the umbellifer plants and lay fewer eggs. For example, the smell of onions is supposed to deter them, and one year I experimented with a mix of carrot and many onions in the same bed. Damage to the carrots was actually worse than normal, so I reckon this is not a foolproof way to protect carrots from pest damage.
• Timing is perhaps our best way to achieve a healthy harvest, if not 100% perfect. Carrot sowings in early spring can give quite big harvests, before the flies arrive in late spring. Then sow in June rather than May for winter carrots, so that you have just the second hatching to contend with.

Some years the flies are less common and you may see no damage. Or you may be on a windy hillside and the flies just keep blowing away before they can lay many eggs.

Other likely difficulties

Splitting roots is perhaps the main issue and usually happens with older carrots, which are more than four months old. It should only happen to a few, and may be encouraged by overwatering.

Carrot shoulders turn a red colour when exposed to light. This is not edible and can simply be cut off, or pull compost over the shoulders of large carrots to keep them orange.

Every so often, during my 40 years of growing carrots, I have noticed a few with discoloured, purple skin, perhaps rotting at the bottom. However, this has never been bad enough that I have needed to find out more. If you are troubled by anything like this, I suggest searching on the internet. Here I don’t want to frighten readers into thinking that diseases can be a major problem. In healthy soil, they are not.

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