Step by step: How to Grow carrots in garden planters

How to Grow Carrots in Planters

Carrots are one of the UK's most popular vegetables but, saying that, they aren’t always easy to grow. Although unusual to have to think of pests the moment you want to grow something it is important, when thinking of growing carrots, to familiarise yourself dreaded carrot fly. It is worth taking time to read our earlier blog 'How to Protect Carrots from Carrot Fly'.

One of the easiest ways to grow carrots successfully and easily is by sowing seeds directly into Carrot Planters - they're ideal for growing in small spaces such as patios, balconies and terraces!

What are the advantages of growing carrots in planters?

Carrots grown from seed in Haxnicks Carrot planter

Carrot planters are a must if you want to grow carrots in container They are specifically designed for carrot plants and work whether you are growing carrots from seed or buying carrot plants. They are deep to allow long straight roots and narrow to allow all plants to get light.

But also, planting in planters will raise your carrots up to avoid more of the carrot flies. Carrot flies only fly to a maximum of around 40 cm from the ground so are less likely to stumble across your crop if its not at ground level.

There is almost no weeding to be done when using carrot planters and you don't need any heavy gardening tools at all, just light, water, and fertilizer.

When is the best time to grow carrots?

Carrots can be grown all year round in all conditions except extreme heat.

Sow from early Spring right through to August. Early August really is the last month where you can sow carrot seeds.

How do you grow carrots in planters or containers?

Step 1: Add a layer of gravel to the bottom of your planter, just level with the drainage hole. If you aren't using a dedicated Haxnicks Carrot planter then make sure your container has drainage holes so your carrots don't sit in water.

Step 2: Add multipurpose compost up to 4cm (1½") from the top of the planter and water if very dry.

Step 3: Mark out 2 trenches 13mm (1/2") deep 15cm (6") apart. I’ve used a bamboo cane here, but you can use a 'dibber' or even a finger if you like!

Step 4: Empty seeds into the palm of your hand – this will make it easier to space the seeds out when you go to sow them in the ‘drills’ you made.

Step 5: Starting with the little finger, roll each digit in a 'Mexican wave' fashion so that the seeds roll off the side of your palm. This takes a bit of practice, so try doing it on a folded sheet of paper first. Remember to sow thinly, carrots need space and 'thinning out' will only increase the risk of attracting carrot fly.

Step 6: Cover over the drills you made with compost and water using a watering can. Make sure the ‘rose’ head attachment is fixed on securely so you don’t wash all the seeds away!

If you have sowed too many seeds then you will need to thin them out. Be very careful when doing this as the scent from bruised carrot seedlings is sure to attract carrot flies.

When should I thin out carrots?

Very young carrots that have been thinned out of a carrot patch on a white background sstk

Once the seedlings are about 2” tall they should be thinned out. Thin to about 1” apart and when 6” tall to 2” apart. At this stage excessive or overwatering should be avoided as it will tend to crack the roots.

Aftercare for planting carrots

Weed the crop regularly making sure not to disturb the roots too much. A good mulch will help to retain moisture and keep the weeds at bay - keep the seedlings well watered in dry weather.

Harvesting and storage

Start to harvest usually 7 - 8 weeks after sowing.

Lift carefully with a fork rather than pulling, especially when the soil is dry. Main crop carrots can be left in the soil and harvested as required. Later in the year you may need to cover with straw of fleece as the temperature drops. Alternatively you can lift your crop in mid Autumn and store in a box of sand or dry potting compost. Trim the foliage to 1cm and make sure the carrots are not touching. Stored in this way they should last throughout the winter.

Remember if you still are growing carrots and parsnips and they are still in the ground by mid-November they should be lifted before the heavy frosts. They can then be stored in a cool place for up to 5 months.

We hope this has shed some light on how to grow carrots for you. Let us know below if you have any questions.

July 22, 2025 — Nicola Wallis

Older articles Back to Grow At Home Newer articles

Comments

Hi Janet, sorry you are having a problem with hornworms.
Yes, Micromesh would help you stop the hornworms (actually caterpillars not worms at all) as it stops the hawk moths from landing on the plant and laying their eggs. However, they usually do this in Spring and early summer so the moths have obviously already laid their eggs which are hatching into caterpillars and eating your plants. So the Micromesh will be good for next year but not for now unless you can clear the plant before putting it on.
If they are in a greenhouse you could introduce beneficial insects like greenfly (try Pippa Greenwood’s website) – you could do this if they are outside too but would be less effective as they may wander off to other plants!
Continue to pick them off by hand (consider taking some of them to a woodland far from any tomato plants and releasing them – the UK is desperately short of moths and these are beauties)

Make sure you thoroughly till the soil where you have grown them before next year and /or plant your tomatoes in a different spot as once they form their chrysalis the pupae fall to the ground and overwinter in the soil before emerging as moths and starting the cycle again.
Lastly, one for this year and next, plant basil around them as the strong scent will prevent the moth finding your tomato plants and laying eggs.
Good luck!

— Haxnicks

I have a terrible time with horn worms on my tomatoes. Will the micromesh keep the horn worms away? Right now I have to hand remove them from my plants.
Thank you! Janet

— Janet

Step by step: How to grow carrots in planters