Unwins Seeds

Growing Carrots

Carrots are a really versatile vegetable and can be eaten raw, roasted, boiled, steamed and turned into soups or drinks. The fluffy foliage is edible too and has a carroty flavour. There’s more to carrots than the usual long orange fingers and varieties include spherical and even yellow and purple colours. They’re not a difficult crop to grow if the soil is suitable and although there are some pests and diseases they are fairly easy to combat.

Soil Requirements for Carrots

Carrots need deep, fertile, free draining, sandy soil. Lots of organic matter or stones will have adverse effects so avoid ground that has previously manured. Instead prepare the soil in autumn and apply a general fertiliser a week or two before sowing. In general an open, sunny site is required but early varieties do well with some protection.

Cultivation of Carrots

Carrots don’t do well when transplanted so are best sown in situ. Temperatures should be above 5°C (41°F) but germinate faster in temperatures above 10°C (50°F). Use a cloche to warm up soil before hand. Sow seeds thinly from March, or more usually April, until June in dills 15cm (6in) apart and 1cm (0.5in) deep. Thin out during the evening to 5 to 8cm (2 to 3in) apart. Erect a 60cm (24in) fleece fence around your patch to protect crop from carrot root fly. It’s important to weed regularly when plants are young. Hand weed to avoid root damage from hoes. Once a canopy has been formed weeds should become suppressed. Keep soil moisture consistent as the roots could split if sporadically overwatered.

Harvesting Carrots

Harvesting can commence from June. Pull up small carrots first to let others mature, back filling holes left by the roots as you go. Maincrops can be pulled later, for storage carrots wait until October.


Pests and Diseases of Carrot

Carrot Root Fly

Green Top

Black Rot


Small Roots

Violet Root Rot

Sclerotinia Rot


Motley Dwarf Virus

Carrot-Willow Aphid


Swift Moth

Growing Carrots 

DifficultyEasy, but requires a bit of time and attention to detail.

Why Grow Carrots? Carrots come in all sorts of sizes, colours and types and each has a unique flavour and harvest time. With careful planning and successive sowing of different varieties, you can have carrots available in the garden for at least nine months of the year.

One of the best things about growing your own carrots is that they taste so much better than shop-bought ones and you can enjoy a variety of different types, too. They can be kept in the ground and harvested when needed when they’re most full of flavour and goodness.

Carrots are well known for being orange-fleshed. As it happens, carrots aren’t naturally orange in colour; wild carrots are naturally red, purple, white or yellow! Dutch breeders developed orange carrots in the 17th century and they were so popular that they became the norm, and are still the most recognised today. Fortunately, the original purple carrots are still available to buy from seed so you can grow your own and experience how tasty and sweet they are.

There are different types of carrot available, each offering different qualities:

Early Summer Varieties 
These can be sown from as early as February and take about 3 – 5 months to grow. They’re mostly eaten fresh but they can be stored in the ground. Early varieties are available in the following types;

  •          Round/square-rooted – suitable for difficult soils.
  •          Amsterdam  - pointed and narrow, excellent raw.
  •          Nantes – Large and cylindrical.

Maincrop Varieties
Produce a later harvest than the early varieties and can store in the ground throughout winter until as late as March. Maincrop varieties are available in the following types:

  •          Chantenay – Medium-sized, reputation for good flavour.
  •          Berlicum – large, cylindrical, matures late.
  •          Autumn King – large, tapered shape and high yielding.
  •          Intermediate – long, large roots.
  •          Imperator – Thin roots with a very sweet flavour. Great for eating raw.

Our Top Varieties
Early summer varieties: Amsterdam ForcingMarionNantes 2
Maincrop varieties: Chantenay Red CoredSugarsnaxAutumn King

When to Sow
Early summer varieties: February – August
Maincrop varieties: April - June

Harvest Time
Early summer varieties: June – November
Maincrop varieties: September - March

Site and Soil
Carrots are a bit particular about where they grow, but if you’ve got the right site for them you’ll find it easy to achieve a successful harvest with them. Carrots thrive in light, deep, fertile, stone-free, well-drained soil and don’t do well in heavy clay soil. The roots tend to fork in freshly manured ground so it’s best to mulch the area several months before sowing. For best results, use Organic Extra lightweight farmyard manure.

If you don’t have an ideal site and soil for carrots, you can grow them in compost in a pot or window box.

How to Grow Carrots from Seeds

You can start sowing early summer varieties from February but it’s advised that you cover with cloches for small tunnels to warm the ground slightly for the first month or so. For the longest lasting harvest of early summer varieties, sow successionally throughout the summer, i.e. sow a new row every month. Maincrop varieties can be sown from April.

Sow into drills in well prepared, fine soil. The drills should be 1 – 2.5cm deep, in rows about 30cm apart.

Carrots are very susceptible to weed competition in early stages, so weed seedlings carefully. Our Great Little Weeder is perfect for weeding between rows quickly and effectively!

Once the carrots are established, the carrot foliage blanket the soil so weeding isn’t as urgent. Carrots don’t require much watering, but it’s a good idea to not let the soil dry out completely because that can cause your carrots to split if it suddenly rains very heavily.

Once the carrots start to grow and become densely packed in their rows that will need thinning out. The smell released when thinning notoriously attracts carrot root fly (one of the worst problem pests with this crop), so it’s worth bearing this in mind when sowing. Try to sow as thinly as possible to prevent the need for thinning out altogether. In most cases it is necessary to thin the carrots out, no matter how thinly they’ve been sown. They should be thinned to a distance of 3 - 5cm (or slightly less for narrower varieties). You can make use of the baby carrots that you pull from the ground, too. They’re very sweet and can be eaten in salads or boiled or steamed and eaten whole.

You’ll be able to tell when you’re carrots are ready for harvesting because you’ll be able to see the 'shoulder’ of the carrot just above the soil surface. They can be left in the ground until they reach the required size, or left to store there until needed. In light soil pull out roots carefully as they reach the required size. In heavier soil you’ll need to push a fork into the ground next to them and gently leaver them out.

Carrots withstand light frost, but are damaged by heavy frost. They can be stored in the following ways:

  • In the ground – This is the best method for retaining flavour, but is best in light, well drained soil. Allow the foliage to die back, or cut back foliage from early November if it hasn’t yet died back, and cover with black polythene to keep it dark and to keep the rain off. For additional protection you can include a layer of cardboard underneath the polythene too. These can be dug up and used when required.
  • Indoors – Lift the carrots before the first heavy frost. Cut the foliage off and lay them in rows in cardboard or wood boxes, each layer separated by a layer of sand. Carrots can be pulled from the box when required

Health Benefits  
The old story that carrots help you see in the dark isn’t just an old wives tale, carrots are rich in beta carotene, a substance with is converted into vitamin A in the body and this is used by the retina to improve your night vision. Carrots also contain falcarinol which is a natural pesticide found in carrots. Recent studies suggest that eating this could help prevent some types of cancer. Its detoxifying properties on the liver make carrots good for the skin and other substances and vitamins in carrots can help reduce cholesterol and reduce the risk of strokes.

Carrot Pests and Diseases:
Carrot fly
 – avoiding carrot fly is very tricky. This is where flies lay eggs at the base of the plant: when hatched tiny maggots tunnel into the roots leaving them holey. There are a number of methods that can help prevent them:

  •          Sow thinly – this can reduce need for thinning out, which creates a smell that attracts carrot fly.
  •          Choose resistant varieties –varieties such as ‘Resistafly’ hove shown to be less popular with carrot fly.
  •          Grow next to onions – the smell of onions can deter carrot root fly, so planting alternate rows of carrots and onions may be effective.
  •          Grow high up – it’s thought that carrot fly stay close to the ground so goring them in a raised bed, bench or window box at least 1m from the ground may work.

For Best Results
If carrot root fly becomes a problem, use Westland Plant Rescue fruit and vegetable bug killer. This concentrated liquid is effective at killing many types of vegetable pest, including carrot root fly.

You May Also Need
The Great Little Weeder – ideal for weeding between rows.
The Ultimate Insect Barrier – keep Carrot Fly off with insect netting!

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