How to grow carrots, choosing varieties, debunking myths and preventing pests

The time has finally come, we are officially in Spring. What a long winter it’s been here in the UK. I found lockdown during the winter much more difficult. The allotment was my saviour during the earlier lockdowns, but during winter you just can’t spend the same amount of time there. This weekend the clocks go forward and I am so excited for some longer evenings spent at the plot.

With the start of Spring comes the start of planting out some seedlings and sowing some seeds directly. In the last week I have planted out my February sown peas and turnips, and over the next week or so I will hopefully plant the rest of my February sowings. I am sowing the vast majority of my seeds this year in modules for easy transplanting.

The only vegetable I am sowing directly this year except for potatoes and parnsips is carrots. Sowing carrots is a skill I have yet to master. My first crop last year I sowed too thinly and of course not all the seeds germinated and we had very patchy rows and few carrots. For the first crop we also didn’t mulch the bed because most advice tells you not to add compost or manure before sowing carrots. For my second crop, I ended up using a bed on which I had recently spread some very well-rotted manure. I sowed these a little more thickly this time and we had full rows and a fantastic crop.

A note on manure/compost

Many will advise against growing carrots in compost or manure because it is believed to make them fork. This may be the case if the manure or compost is not well rotted and dug into the bed, but mulching well-rotted organic matter on top is completely fine. By mulching the bed, you are feeding the organisms in the soil that help loosen and aerate the soil naturally. On top of this, compost is much better at retaining moisture than soil and therefore will help prevent your carrot bed from drying out as easily.

Prepping the bed

This year I have tried to replicate what I did with my second sowing last year. We prepped the bed by weeding and we also raked it to remove some of the surface stones. We have quite stony soil but not stony enough to justify sifting it. Some people may wish to sift stony soil for carrots because when the carrot roots hit a stone they fork. However, it is probably only worth doing so if your soil is really stony because it will cause huge disturbance to the living organisms that keep it healthy. Once the soil was raked, we evenly spread a layer of mature compost on the surface of the bed. We haven’t dug the soil and instead we’re letting nature do the work for us.

Spacing and sowing

I created drills in the compost 6 inches apart using a long handled dibber. Last season I used a hoe to create drills – this was perfectly doable but definitely more faffy. In my 4 foot wide bed, I was able to create 7 drills with 6 inches space either side. Once the drills were made, I thoroughly watered them before sowing the seeds.

Sowing carrots definitely takes some practice to get right. Sow them too thinly and you get patchy rows. Sow them too thickly and you have to thin them out a lot. The aim is to space seeds roughly 1cm apart, but in reality this is very difficult to achieve perfectly. There was a big difference between the first and last rows that I sowed, as I practiced and started to get a little better. I definitely found that sprinkling smaller pinches of seeds made it easier to control. Once the seeds were sown, I lightly covered them back over with compost from the bed. I also covered them with some fleece to give me faster germination and growth.

Carrot fly

The reason you want to avoid thinning your carrots is because the process of thinning releases a scent which attracts carrot fly. Carrot fly lay their eggs on your carrots and then the larvae feed on them, leaving behind tunnels and causing them to rot. Believe me, it is not nice cutting into your carrots and finding little white maggots in them. I thinned my carrots out last year by harvesting the largest first and allowing the smaller ones to grow on. This worked well until the later harvested carrots, many of which became barely useable. I have since learned that carrot fly are less active in the evenings, so if you need to thin them out it is best to do so on a still evening.

There are various methods of protection against carrot fly. It is said that carrot fly do not fly over 2 foot (60cm) high. By putting up a mesh around your carrots or having them in a deep raised bed this may reduce the problem. However from my experience, you probably want it to be higher than 2 feet because external factors such as wind can give them that little extra height they need. This year I’m going to try completely covering my carrots in mesh because unfortunately my 2 foot high mesh barrier didn’t do the trick. Companion planting is another method some people use. Onions and garlic appear to be the most popular for this because the scent is said to deter carrot fly.

Timings of sowing

When you sow your carrots is entirely down to what works best for you. If you want to ensure a constant stream of young and tender carrots then it is probably best to sow a couple of rows at least once a month. Many people like to enjoy smaller, more tender carrots through the summer. For your main crop for winter storage, larger roots tend to store better than smaller.

I will be doing two sowings of carrots this year. My first crop has been sown just a few days ago which I intend to harvest throughout June and July. I then intend to plant purple sprouting broccoli in that bed as the carrots are finishing. My second (maincrop) sowing will be between my onion rows around a month before I expect to harvest them, so I will probably sow them around the end of June. I accept that I will probably have a dry spell of carrots through the month of August, but I am hopeful I can store a few to tide me over. August is possibly the most abundant month in the garden in the UK, so I don’t mind too much if I have a short while without fresh carrots. For some this may not be an option.

Carrot varieties

Just like most crops, there are so many varieties of carrots to choose from. You can get both early and maincrop varieties. Early varieties tend to be quicker maturing and more tender, while maincrop varieties tend to be better for storing. For my first sowing of carrots I sowed the variety Early Nantes and for my maincrop this year I have Autumn King.

If you are growing your carrots in containers you may wish to grow varieties that don’t grow as long, such as Chantenay, Paris Market or Little Finger. There are also some varieties of carrots that are less susceptible to carrot fly. Please note that this doesn’t mean they are completely safe. These tend to be F1 varieties however, so they are more expensive and you can’t save the seed. I have written a previous post about F1 varieties here. Carrot fly resistant varieties include Resistafly F1 and Flyaway F1.

You can also get carrots in a variety of colours which vary hugely in flavour and sweetness. Different coloured carrots are something I am very much looking forward to growing because it makes your plate look so exciting. It’s also nice to grow different coloured carrots because they are difficult to buy. Definitely experiment with different varieties and colours of carrots to see which you like best. Afterall, one of the best perks of growing your own is the ability to have beautiful tasty produce that you cannot buy.