Carrots, in my opinion, are the best vegetable to show up the difference between home-grown and shop bought – the flavour is far stronger and depending on variety can be on the spectrum from sweet to almost peppery.
They need well drained and stone-free soil; the need to go looking for water is what makes them grow their long root down, and if they hit any stones they will fork. A few odd, twisty carrots can be funny, but if they are all distorted then cleaning them is a pain and you have a smaller usable crop.
They can of course be grown in the ground, but also do well in pots.
Carrots love fine, well drained compost, and that can be easier to provide in pots than in Bristol soil, I use a 50:50 mix of compost and horticultural sand. You can alternatively use last year’s ‘spent’ compost from growbags and pots.
The other advantage of container growing is that the main pest, carrot fly, doesn’t fly higher than 45cm above the ground – just raise the pot’s top above this and they are safe.
Carrots need containers deeper than you might think as they have long tap roots beyond the bit we eat. But with the right variety troughs are fine, just use round varieties such as ‘Paris Market’ or ”Atlas’. For 20cm pots short carrots such as ‘Amsterdam Forcing’ or for 30cm pots go for ‘Chantenay Red Cored’ or ‘Nantes 2’, both long established favourites for flavour.
Terracotta pots are nicer than plastic, and cheaper than glazed pots, but because they are porous they dry out quickly. To stop that I line them with some plastic, usually a compost bag. Cut it out flat, and line the sides, leaving the base clear, cut to about 3cm below the rim so it won’t show. Fill to 2cm below the top when lightly compressed.
Carrots can grow almost shoulder to shoulder and I aim for equal spacing of 7cm. As not all seeds grow I make shallow dents a few millimetres deep and put 3 seeds in each. Cover and water gently.
When the plants are 2cm tall I reduce each group to one plant by nipping out the other leaves between my nails. (Pulling them out can disturb the ones you want to keep)
Place somewhere with 6 hours of sun a day and water gently every day,
Carrots will be ready to harvest between 6 -12 weeks depending on variety. Plant some every few weeks in summer.
In the ground
If you are growing into a garden bed then dig it over when it is dry enough for the soil to fall back off your tools and mix in any material that will make the soil lighter and drain more easily without adding too much nutrient: leafmould, last year’s compost or horticultural sand or grit are all good. Take out any stones you find.
Carrots can grow almost shoulder to shoulder, and packets will give an idea of spacing for each variety. I put rows just wide enough to hoe between -12cm or so, and aim for one seed a centimetre.
They will need thinning to one per 7cm, but you can do this in stages, first when 2cm tall take out to 3 or 4cm apart and then a few weeks later take out every other one and eat them, tiny but delicious.
Protect from carrot fly by thinning in the evening when they aren’t around, leave the thinnings away somewhere on a hard surface to fool them, and cover the crop with environmesh or fleece. A 60cm fence of fleece, instead of a complete ‘tent’ also works, though one day I’m sure a carrot fly will evolve that flies higher than 45cm and we will have to up the boundary defences.
The choice of carrots in the ground is wider, but if the soil is less than ideal – clayey or stoney, then stick to the stump rooted ones. If you have nice deep soil there is a huge choice, including coloured novelties (Suttons do a mixed ‘Rainbow’ pack) and varieties bred to resist carrot fly attack (e.g. ‘ResistaflyF1’, ‘Maestro F1’) or both – ‘Samurai’ a bright red carrot that keeps it’s colour cooked.